From 187f19b1704b8a877b53a3e66c67ec26383a3ee9 Mon Sep 17 00:00:00 2001 From: zotlabs Date: Sat, 26 Aug 2017 17:21:33 -0700 Subject: fix titles on ajaxupdate issue, add jsonld-php library --- library/jsonld/LICENSE | 30 + library/jsonld/README.md | 193 ++ library/jsonld/composer.json | 29 + library/jsonld/jsonld.php | 6038 ++++++++++++++++++++++++++++++++++++++++++ library/jsonld/test.php | 765 ++++++ 5 files changed, 7055 insertions(+) create mode 100644 library/jsonld/LICENSE create mode 100644 library/jsonld/README.md create mode 100644 library/jsonld/composer.json create mode 100644 library/jsonld/jsonld.php create mode 100644 library/jsonld/test.php (limited to 'library/jsonld') diff --git a/library/jsonld/LICENSE b/library/jsonld/LICENSE new file mode 100644 index 000000000..bd572d3e0 --- /dev/null +++ b/library/jsonld/LICENSE @@ -0,0 +1,30 @@ +BSD 3-Clause License +Copyright (c) 2011, Digital Bazaar, Inc. +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimer. + +Redistributions in binary form must reproduce the above copyright +notice, this list of conditions and the following disclaimer in the +documentation and/or other materials provided with the distribution. + +Neither the name of the Digital Bazaar, Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED +TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + diff --git a/library/jsonld/README.md b/library/jsonld/README.md new file mode 100644 index 000000000..5853c94bf --- /dev/null +++ b/library/jsonld/README.md @@ -0,0 +1,193 @@ +php-json-ld +=========== + +[![Build Status][travis-ci-png]][travis-ci-site] +[travis-ci-png]: https://travis-ci.org/digitalbazaar/php-json-ld.png?branch=master +[travis-ci-site]: https://travis-ci.org/digitalbazaar/php-json-ld + +Introduction +------------ + +This library is an implementation of the [JSON-LD][] specification in [PHP][]. + +JSON, as specified in [RFC7159][], is a simple language for representing +objects on the Web. Linked Data is a way of describing content across +different documents or Web sites. Web resources are described using +IRIs, and typically are dereferencable entities that may be used to find +more information, creating a "Web of Knowledge". [JSON-LD][] is intended +to be a simple publishing method for expressing not only Linked Data in +JSON, but for adding semantics to existing JSON. + +JSON-LD is designed as a light-weight syntax that can be used to express +Linked Data. It is primarily intended to be a way to express Linked Data +in JavaScript and other Web-based programming environments. It is also +useful when building interoperable Web Services and when storing Linked +Data in JSON-based document storage engines. It is practical and +designed to be as simple as possible, utilizing the large number of JSON +parsers and existing code that is in use today. It is designed to be +able to express key-value pairs, RDF data, [RDFa][] data, +[Microformats][] data, and [Microdata][]. That is, it supports every +major Web-based structured data model in use today. + +The syntax does not require many applications to change their JSON, but +easily add meaning by adding context in a way that is either in-band or +out-of-band. The syntax is designed to not disturb already deployed +systems running on JSON, but provide a smooth migration path from JSON +to JSON with added semantics. Finally, the format is intended to be fast +to parse, fast to generate, stream-based and document-based processing +compatible, and require a very small memory footprint in order to operate. + +## Quick Examples + +```php +$doc = (object)array( + "http://schema.org/name" => "Manu Sporny", + "http://schema.org/url" => (object)array("@id" => "http://manu.sporny.org/"), + "http://schema.org/image" => (object)array("@id" => "http://manu.sporny.org/images/manu.png") +); + +$context = (object)array( + "name" => "http://schema.org/name", + "homepage" => (object)array("@id" => "http://schema.org/url", "@type" => "@id"), + "image" => (object)array("@id" => "http://schema.org/image", "@type" => "@id") +); + +// compact a document according to a particular context +// see: http://json-ld.org/spec/latest/json-ld/#compacted-document-form +$compacted = jsonld_compact($doc, $context); + +echo json_encode($compacted, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES); +/* Output: +{ + "@context": {...}, + "image": "http://manu.sporny.org/images/manu.png", + "homepage": "http://manu.sporny.org/", + "name": "Manu Sporny" +} +*/ + +// compact using URLs +jsonld_compact('http://example.org/doc', 'http://example.org/context'); + +// expand a document, removing its context +// see: http://json-ld.org/spec/latest/json-ld/#expanded-document-form +$expanded = jsonld_expand($compacted) { +echo json_encode($expanded, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES); +/* Output: +{ + "http://schema.org/image": [{"@id": "http://manu.sporny.org/images/manu.png"}], + "http://schema.org/name": [{"@value": "Manu Sporny"}], + "http://schema.org/url": [{"@id": "http://manu.sporny.org/"}] +} +*/ + +// expand using URLs +jsonld_expand('http://example.org/doc'); + +// flatten a document +// see: http://json-ld.org/spec/latest/json-ld/#flattened-document-form +$flattened = jsonld_flatten($doc); +// all deep-level trees flattened to the top-level + +// frame a document +// see: http://json-ld.org/spec/latest/json-ld-framing/#introduction +$framed = jsonld_frame($doc, $frame); +// document transformed into a particular tree structure per the given frame + +// normalize a document using the RDF Dataset Normalization Algorithm +// (URDNA2015), see: http://json-ld.github.io/normalization/spec/ +$normalized = jsonld_normalize( + $doc, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads')); +// normalized is a string that is a canonical representation of the document +// that can be used for hashing, comparison, etc. + +// force HTTPS-only context loading: +// use built-in secure document loader +jsonld_set_document_loader('jsonld_default_secure_document_loader'); + +// set a default custom document loader +jsonld_set_document_loader('my_custom_doc_loader'); + +// a custom loader that demonstrates using a simple in-memory mock for +// certain contexts before falling back to the default loader +// note: if you want to set this loader as the new default, you'll need to +// store the previous default in another variable first and access that inside +// the loader +global $mocks; +$mocks = array('http://example.com/mycontext' => (object)array( + 'hombre' => 'http://schema.org/name')); +function mock_load($url) { + global $jsonld_default_load_document, $mocks; + if(isset($mocks[$url])) { + // return a "RemoteDocument", it has these three properties: + return (object)array( + 'contextUrl' => null, + 'document' => $mocks[$url], + 'documentUrl' => $url); + } + // use default loader + return call_user_func($jsonld_default_load_document, $url); +} + +// use the mock loader for just this call, witout modifying the default one +$compacted = jsonld_compact($foo, 'http://example.com/mycontext', array( + 'documentLoader' => 'mock_load')); + +// a custom loader that uses a simplistic in-memory cache (no invalidation) +global $cache; +$cache = array(); +function cache_load($url) { + global $jsonld_default_load_document, $cache; + if(isset($cache[$url])) { + return $cache[$url]; + } + // use default loader + $doc = call_user_func($jsonld_default_load_document, $url); + $cache[$url] = $doc; + return $doc; +} + +// use the cache loader for just this call, witout modifying the default one +$compacted = jsonld_compact($foo, 'http://schema.org', array( + 'documentLoader' => 'cache_load')); +``` + +Commercial Support +------------------ + +Commercial support for this library is available upon request from +[Digital Bazaar][]: support@digitalbazaar.com + +Source +------ + +The source code for the PHP implementation of the JSON-LD API +is available at: + +http://github.com/digitalbazaar/php-json-ld + +Tests +----- + +This library includes a sample testing utility which may be used to verify +that changes to the processor maintain the correct output. + +To run the sample tests you will need to get the test suite files by cloning +the `json-ld.org` and `normalization` repositories hosted on GitHub: + +- https://github.com/json-ld/json-ld.org +- https://github.com/json-ld/normalization + +Then run the PHPUnit test.php application and point it at the directories +containing the tests: + + phpunit --group json-ld.org test.php -d {PATH_TO_JSON_LD_ORG/test-suite} + phpunit --group normalization test.php -d {PATH_TO_NORMALIZATION/tests} + +[Digital Bazaar]: http://digitalbazaar.com/ +[JSON-LD]: http://json-ld.org/ +[Microdata]: http://www.w3.org/TR/microdata/ +[Microformats]: http://microformats.org/ +[PHP]: http://php.net +[RDFa]: http://www.w3.org/TR/rdfa-core/ +[RFC7159]: http://tools.ietf.org/html/rfc7159 diff --git a/library/jsonld/composer.json b/library/jsonld/composer.json new file mode 100644 index 000000000..cc985b23e --- /dev/null +++ b/library/jsonld/composer.json @@ -0,0 +1,29 @@ +{ + "name": "digitalbazaar/json-ld", + "type": "library", + "description": "A JSON-LD Processor and API implementation in PHP.", + "keywords": [ + "JSON", + "Linked Data", + "JSON-LD", + "RDF", + "Semantic Web", + "jsonld" + ], + "homepage": "https://github.com/digitalbazaar/php-json-ld", + "license": "BSD-3-Clause", + "authors": [ + { + "name": "Digital Bazaar, Inc.", + "email": "support@digitalbazaar.com", + "url": "http://digitalbazaar.com/" + } + ], + "require": { + "php": ">=5.3.0", + "ext-json": "*" + }, + "autoload": { + "files": [ "jsonld.php" ] + } +} diff --git a/library/jsonld/jsonld.php b/library/jsonld/jsonld.php new file mode 100644 index 000000000..28b3e7ce3 --- /dev/null +++ b/library/jsonld/jsonld.php @@ -0,0 +1,6038 @@ +compact($input, $ctx, $options); +} + +/** + * Performs JSON-LD expansion. + * + * @param mixed $input the JSON-LD object to expand. + * @param assoc[$options] the options to use: + * [base] the base IRI to use. + * [documentLoader(url)] the document loader. + * + * @return array the expanded JSON-LD output. + */ +function jsonld_expand($input, $options=array()) { + $p = new JsonLdProcessor(); + return $p->expand($input, $options); +} + +/** + * Performs JSON-LD flattening. + * + * @param mixed $input the JSON-LD to flatten. + * @param mixed $ctx the context to use to compact the flattened output, or + * null. + * @param [options] the options to use: + * [base] the base IRI to use. + * [documentLoader(url)] the document loader. + * + * @return mixed the flattened JSON-LD output. + */ +function jsonld_flatten($input, $ctx, $options=array()) { + $p = new JsonLdProcessor(); + return $p->flatten($input, $ctx, $options); +} + +/** + * Performs JSON-LD framing. + * + * @param mixed $input the JSON-LD object to frame. + * @param stdClass $frame the JSON-LD frame to use. + * @param assoc [$options] the framing options. + * [base] the base IRI to use. + * [embed] default @embed flag (default: true). + * [explicit] default @explicit flag (default: false). + * [requireAll] default @requireAll flag (default: true). + * [omitDefault] default @omitDefault flag (default: false). + * [documentLoader(url)] the document loader. + * + * @return stdClass the framed JSON-LD output. + */ +function jsonld_frame($input, $frame, $options=array()) { + $p = new JsonLdProcessor(); + return $p->frame($input, $frame, $options); +} + +/** + * **Experimental** + * + * Links a JSON-LD document's nodes in memory. + * + * @param mixed $input the JSON-LD document to link. + * @param mixed $ctx the JSON-LD context to apply or null. + * @param assoc [$options] the options to use: + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [documentLoader(url)] the document loader. + * + * @return the linked JSON-LD output. + */ +function jsonld_link($input, $ctx, $options) { + // API matches running frame with a wildcard frame and embed: '@link' + // get arguments + $frame = new stdClass(); + if($ctx) { + $frame->{'@context'} = $ctx; + } + $frame->{'@embed'} = '@link'; + return jsonld_frame($input, $frame, $options); +}; + +/** + * Performs RDF dataset normalization on the given input. The input is + * JSON-LD unless the 'inputFormat' option is used. The output is an RDF + * dataset unless the 'format' option is used. + * + * @param mixed $input the JSON-LD object to normalize. + * @param assoc [$options] the options to use: + * [base] the base IRI to use. + * [intputFormat] the format if input is not JSON-LD: + * 'application/nquads' for N-Quads. + * [format] the format if output is a string: + * 'application/nquads' for N-Quads. + * [documentLoader(url)] the document loader. + * + * @return mixed the normalized output. + */ +function jsonld_normalize($input, $options=array()) { + $p = new JsonLdProcessor(); + return $p->normalize($input, $options); +} + +/** + * Converts an RDF dataset to JSON-LD. + * + * @param mixed $input a serialized string of RDF in a format specified + * by the format option or an RDF dataset to convert. + * @param assoc [$options] the options to use: + * [format] the format if input not an array: + * 'application/nquads' for N-Quads (default). + * [useRdfType] true to use rdf:type, false to use @type + * (default: false). + * [useNativeTypes] true to convert XSD types into native types + * (boolean, integer, double), false not to (default: false). + * + * @return array the JSON-LD output. + */ +function jsonld_from_rdf($input, $options=array()) { + $p = new JsonLdProcessor(); + return $p->fromRDF($input, $options); +} + +/** + * Outputs the RDF dataset found in the given JSON-LD object. + * + * @param mixed $input the JSON-LD object. + * @param assoc [$options] the options to use: + * [base] the base IRI to use. + * [format] the format to use to output a string: + * 'application/nquads' for N-Quads. + * [produceGeneralizedRdf] true to output generalized RDF, false + * to produce only standard RDF (default: false). + * [documentLoader(url)] the document loader. + * + * @return mixed the resulting RDF dataset (or a serialization of it). + */ +function jsonld_to_rdf($input, $options=array()) { + $p = new JsonLdProcessor(); + return $p->toRDF($input, $options); +} + +/** + * JSON-encodes (with unescaped slashes) the given stdClass or array. + * + * @param mixed $input the native PHP stdClass or array which will be + * converted to JSON by json_encode(). + * @param int $options the options to use. + * [JSON_PRETTY_PRINT] pretty print. + * @param int $depth the maximum depth to use. + * + * @return the encoded JSON data. + */ +function jsonld_encode($input, $options=0, $depth=512) { + // newer PHP has a flag to avoid escaped '/' + if(defined('JSON_UNESCAPED_SLASHES')) { + return json_encode($input, JSON_UNESCAPED_SLASHES | $options, $depth); + } + // use a simple string replacement of '\/' to '/'. + return str_replace('\\/', '/', json_encode($input, $options, $depth)); +} + +/** + * Decodes a serialized JSON-LD object. + * + * @param string $input the JSON-LD input. + * + * @return mixed the resolved JSON-LD object, null on error. + */ +function jsonld_decode($input) { + return json_decode($input); +} + +/** + * Parses a link header. The results will be key'd by the value of "rel". + * + * Link: ; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json" + * + * Parses as: { + * 'http://www.w3.org/ns/json-ld#context': { + * target: http://json-ld.org/contexts/person.jsonld, + * type: 'application/ld+json' + * } + * } + * + * If there is more than one "rel" with the same IRI, then entries in the + * resulting map for that "rel" will be arrays of objects, otherwise they will + * be single objects. + * + * @param string $header the link header to parse. + * + * @return assoc the parsed result. + */ +function jsonld_parse_link_header($header) { + $rval = array(); + // split on unbracketed/unquoted commas + if(!preg_match_all( + '/(?:<[^>]*?>|"[^"]*?"|[^,])+/', $header, $entries, PREG_SET_ORDER)) { + return $rval; + } + $r_link_header = '/\s*<([^>]*?)>\s*(?:;\s*(.*))?/'; + foreach($entries as $entry) { + if(!preg_match($r_link_header, $entry[0], $match)) { + continue; + } + $result = (object)array('target' => $match[1]); + $params = $match[2]; + $r_params = '/(.*?)=(?:(?:"([^"]*?)")|([^"]*?))\s*(?:(?:;\s*)|$)/'; + preg_match_all($r_params, $params, $matches, PREG_SET_ORDER); + foreach($matches as $match) { + $result->{$match[1]} = $match[2] ?: $match[3]; + } + $rel = property_exists($result, 'rel') ? $result->rel : ''; + if(!isset($rval[$rel])) { + $rval[$rel] = $result; + } else if(is_array($rval[$rel])) { + $rval[$rel][] = $result; + } else { + $rval[$rel] = array($rval[$rel], $result); + } + } + return $rval; +} + +/** + * Relabels all blank nodes in the given JSON-LD input. + * + * @param mixed input the JSON-LD input. + */ +function jsonld_relabel_blank_nodes($input) { + $p = new JsonLdProcessor(); + return $p->_labelBlankNodes(new UniqueNamer('_:b'), $input); +} + +/** JSON-LD shared in-memory cache. */ +global $jsonld_cache; +$jsonld_cache = new stdClass(); + +/** The default active context cache. */ +$jsonld_cache->activeCtx = new ActiveContextCache(); + +/** Stores the default JSON-LD document loader. */ +global $jsonld_default_load_document; +$jsonld_default_load_document = 'jsonld_default_document_loader'; + +/** + * Sets the default JSON-LD document loader. + * + * @param callable load_document(url) the document loader. + */ +function jsonld_set_document_loader($load_document) { + global $jsonld_default_load_document; + $jsonld_default_load_document = $load_document; +} + +/** + * Retrieves JSON-LD at the given URL. + * + * @param string $url the URL to retrieve. + * + * @return the JSON-LD. + */ +function jsonld_get_url($url) { + global $jsonld_default_load_document; + if($jsonld_default_load_document !== null) { + $document_loader = $jsonld_default_load_document; + } else { + $document_loader = 'jsonld_default_document_loader'; + } + + $remote_doc = call_user_func($document_loader, $url); + if($remote_doc) { + return $remote_doc->document; + } + return null; +} + +/** + * The default implementation to retrieve JSON-LD at the given URL. + * + * @param string $url the URL to to retrieve. + * + * @return stdClass the RemoteDocument object. + */ +function jsonld_default_document_loader($url) { + $doc = (object)array( + 'contextUrl' => null, 'document' => null, 'documentUrl' => $url); + $redirects = array(); + + $opts = array( + 'http' => array( + 'method' => 'GET', + 'header' => + "Accept: application/ld+json\r\n"), + /* Note: Use jsonld_default_secure_document_loader for security. */ + 'ssl' => array( + 'verify_peer' => false, + 'allow_self_signed' => true) + ); + + $context = stream_context_create($opts); + $content_type = null; + stream_context_set_params($context, array('notification' => + function($notification_code, $severity, $message) use ( + &$redirects, &$content_type) { + switch($notification_code) { + case STREAM_NOTIFY_REDIRECTED: + $redirects[] = $message; + break; + case STREAM_NOTIFY_MIME_TYPE_IS: + $content_type = $message; + break; + }; + })); + $result = @file_get_contents($url, false, $context); + if($result === false) { + throw new JsonLdException( + 'Could not retrieve a JSON-LD document from the URL: ' . $url, + 'jsonld.LoadDocumentError', 'loading document failed'); + } + $link_header = array(); + foreach($http_response_header as $header) { + if(strpos($header, 'link') === 0) { + $value = explode(': ', $header); + if(count($value) > 1) { + $link_header[] = $value[1]; + } + } + } + $link_header = jsonld_parse_link_header(join(',', $link_header)); + if(isset($link_header['http://www.w3.org/ns/json-ld#context'])) { + $link_header = $link_header['http://www.w3.org/ns/json-ld#context']; + } else { + $link_header = null; + } + if($link_header && $content_type !== 'application/ld+json') { + // only 1 related link header permitted + if(is_array($link_header)) { + throw new JsonLdException( + 'URL could not be dereferenced, it has more than one ' . + 'associated HTTP Link Header.', 'jsonld.LoadDocumentError', + 'multiple context link headers', array('url' => $url)); + } + $doc->{'contextUrl'} = $link_header->target; + } + + // update document url based on redirects + $redirs = count($redirects); + if($redirs > 0) { + $url = $redirects[$redirs - 1]; + } + $doc->document = $result; + $doc->documentUrl = $url; + return $doc; +} + +/** + * The default implementation to retrieve JSON-LD at the given secure URL. + * + * @param string $url the secure URL to to retrieve. + * + * @return stdClass the RemoteDocument object. + */ +function jsonld_default_secure_document_loader($url) { + if(strpos($url, 'https') !== 0) { + throw new JsonLdException( + "Could not GET url: '$url'; 'https' is required.", + 'jsonld.LoadDocumentError', 'loading document failed'); + } + + $doc = (object)array( + 'contextUrl' => null, 'document' => null, 'documentUrl' => $url); + $redirects = array(); + + // default JSON-LD https GET implementation + $opts = array( + 'http' => array( + 'method' => 'GET', + 'header' => + "Accept: application/ld+json\r\n"), + 'ssl' => array( + 'verify_peer' => true, + 'allow_self_signed' => false, + 'cafile' => '/etc/ssl/certs/ca-certificates.crt')); + $context = stream_context_create($opts); + $content_type = null; + stream_context_set_params($context, array('notification' => + function($notification_code, $severity, $message) use ( + &$redirects, &$content_type) { + switch($notification_code) { + case STREAM_NOTIFY_REDIRECTED: + $redirects[] = $message; + break; + case STREAM_NOTIFY_MIME_TYPE_IS: + $content_type = $message; + break; + }; + })); + $result = @file_get_contents($url, false, $context); + if($result === false) { + throw new JsonLdException( + 'Could not retrieve a JSON-LD document from the URL: ' + $url, + 'jsonld.LoadDocumentError', 'loading document failed'); + } + $link_header = array(); + foreach($http_response_header as $header) { + if(strpos($header, 'link') === 0) { + $value = explode(': ', $header); + if(count($value) > 1) { + $link_header[] = $value[1]; + } + } + } + $link_header = jsonld_parse_link_header(join(',', $link_header)); + if(isset($link_header['http://www.w3.org/ns/json-ld#context'])) { + $link_header = $link_header['http://www.w3.org/ns/json-ld#context']; + } else { + $link_header = null; + } + if($link_header && $content_type !== 'application/ld+json') { + // only 1 related link header permitted + if(is_array($link_header)) { + throw new JsonLdException( + 'URL could not be dereferenced, it has more than one ' . + 'associated HTTP Link Header.', 'jsonld.LoadDocumentError', + 'multiple context link headers', array('url' => $url)); + } + $doc->{'contextUrl'} = $link_header->target; + } + + // update document url based on redirects + foreach($redirects as $redirect) { + if(strpos($redirect, 'https') !== 0) { + throw new JsonLdException( + "Could not GET redirected url: '$redirect'; 'https' is required.", + 'jsonld.LoadDocumentError', 'loading document failed'); + } + $url = $redirect; + } + $doc->document = $result; + $doc->documentUrl = $url; + return $doc; +} + +/** Registered global RDF dataset parsers hashed by content-type. */ +global $jsonld_rdf_parsers; +$jsonld_rdf_parsers = new stdClass(); + +/** + * Registers a global RDF dataset parser by content-type, for use with + * jsonld_from_rdf. Global parsers will be used by JsonLdProcessors that do + * not register their own parsers. + * + * @param string $content_type the content-type for the parser. + * @param callable $parser(input) the parser function (takes a string as + * a parameter and returns an RDF dataset). + */ +function jsonld_register_rdf_parser($content_type, $parser) { + global $jsonld_rdf_parsers; + $jsonld_rdf_parsers->{$content_type} = $parser; +} + +/** + * Unregisters a global RDF dataset parser by content-type. + * + * @param string $content_type the content-type for the parser. + */ +function jsonld_unregister_rdf_parser($content_type) { + global $jsonld_rdf_parsers; + if(property_exists($jsonld_rdf_parsers, $content_type)) { + unset($jsonld_rdf_parsers->{$content_type}); + } +} + +/** + * Parses a URL into its component parts. + * + * @param string $url the URL to parse. + * + * @return assoc the parsed URL. + */ +function jsonld_parse_url($url) { + if($url === null) { + $url = ''; + } + + $keys = array( + 'href', 'protocol', 'scheme', '?authority', 'authority', + '?auth', 'auth', 'user', 'pass', 'host', '?port', 'port', 'path', + '?query', 'query', '?fragment', 'fragment'); + $regex = "/^(([^:\/?#]+):)?(\/\/(((([^:@]*)(?::([^:@]*))?)?@)?([^:\/?#]*)(:(\d*))?))?([^?#]*)(\?([^#]*))?(#(.*))?/"; + preg_match($regex, $url, $match); + + $rval = array(); + $flags = array(); + $len = count($keys); + for($i = 0; $i < $len; ++$i) { + $key = $keys[$i]; + if(strpos($key, '?') === 0) { + $flags[substr($key, 1)] = !empty($match[$i]); + } else if(!isset($match[$i])) { + $rval[$key] = null; + } else { + $rval[$key] = $match[$i]; + } + } + + if(!$flags['authority']) { + $rval['authority'] = null; + } + if(!$flags['auth']) { + $rval['auth'] = $rval['user'] = $rval['pass'] = null; + } + if(!$flags['port']) { + $rval['port'] = null; + } + if(!$flags['query']) { + $rval['query'] = null; + } + if(!$flags['fragment']) { + $rval['fragment'] = null; + } + + $rval['normalizedPath'] = jsonld_remove_dot_segments( + $rval['path'], !!$rval['authority']); + + return $rval; +} + +/** + * Removes dot segments from a URL path. + * + * @param string $path the path to remove dot segments from. + * @param bool $has_authority true if the URL has an authority, false if not. + */ +function jsonld_remove_dot_segments($path, $has_authority) { + $rval = ''; + + if(strpos($path, '/') === 0) { + $rval = '/'; + } + + // RFC 3986 5.2.4 (reworked) + $input = explode('/', $path); + $output = array(); + while(count($input) > 0) { + if($input[0] === '.' || ($input[0] === '' && count($input) > 1)) { + array_shift($input); + continue; + } + if($input[0] === '..') { + array_shift($input); + if($has_authority || + (count($output) > 0 && $output[count($output) - 1] !== '..')) { + array_pop($output); + } else { + // leading relative URL '..' + $output[] = '..'; + } + continue; + } + $output[] = array_shift($input); + } + + return $rval . implode('/', $output); +} + +/** + * Prepends a base IRI to the given relative IRI. + * + * @param mixed $base a string or the parsed base IRI. + * @param string $iri the relative IRI. + * + * @return string the absolute IRI. + */ +function jsonld_prepend_base($base, $iri) { + // skip IRI processing + if($base === null) { + return $iri; + } + + // already an absolute IRI + if(strpos($iri, ':') !== false) { + return $iri; + } + + // parse base if it is a string + if(is_string($base)) { + $base = jsonld_parse_url($base); + } + + // parse given IRI + $rel = jsonld_parse_url($iri); + + // per RFC3986 5.2.2 + $transform = array('protocol' => $base['protocol']); + + if($rel['authority'] !== null) { + $transform['authority'] = $rel['authority']; + $transform['path'] = $rel['path']; + $transform['query'] = $rel['query']; + } else { + $transform['authority'] = $base['authority']; + + if($rel['path'] === '') { + $transform['path'] = $base['path']; + if($rel['query'] !== null) { + $transform['query'] = $rel['query']; + } else { + $transform['query'] = $base['query']; + } + } else { + if(strpos($rel['path'], '/') === 0) { + // IRI represents an absolute path + $transform['path'] = $rel['path']; + } else { + // merge paths + $path = $base['path']; + + // append relative path to the end of the last directory from base + if($rel['path'] !== '') { + $idx = strrpos($path, '/'); + $idx = ($idx === false) ? 0 : $idx + 1; + $path = substr($path, 0, $idx); + if(strlen($path) > 0 && substr($path, -1) !== '/') { + $path .= '/'; + } + $path .= $rel['path']; + } + + $transform['path'] = $path; + } + $transform['query'] = $rel['query']; + } + } + + // remove slashes and dots in path + $transform['path'] = jsonld_remove_dot_segments( + $transform['path'], !!$transform['authority']); + + // construct URL + $rval = $transform['protocol']; + if($transform['authority'] !== null) { + $rval .= '//' . $transform['authority']; + } + $rval .= $transform['path']; + if($transform['query'] !== null) { + $rval .= '?' . $transform['query']; + } + if($rel['fragment'] !== null) { + $rval .= '#' . $rel['fragment']; + } + + // handle empty base + if($rval === '') { + $rval = './'; + } + + return $rval; +} + +/** + * Removes a base IRI from the given absolute IRI. + * + * @param mixed $base the base IRI. + * @param string $iri the absolute IRI. + * + * @return string the relative IRI if relative to base, otherwise the absolute + * IRI. + */ +function jsonld_remove_base($base, $iri) { + // skip IRI processing + if($base === null) { + return $iri; + } + + if(is_string($base)) { + $base = jsonld_parse_url($base); + } + + // establish base root + $root = ''; + if($base['href'] !== '') { + $root .= "{$base['protocol']}//{$base['authority']}"; + } else if(strpos($iri, '//') === false) { + // support network-path reference with empty base + $root .= '//'; + } + + // IRI not relative to base + if($root === '' || strpos($iri, $root) !== 0) { + return $iri; + } + + // remove root from IRI + $rel = jsonld_parse_url(substr($iri, strlen($root))); + + // remove path segments that match (do not remove last segment unless there + // is a hash or query) + $base_segments = explode('/', $base['normalizedPath']); + $iri_segments = explode('/', $rel['normalizedPath']); + $last = ($rel['query'] || $rel['fragment']) ? 0 : 1; + while(count($base_segments) > 0 && count($iri_segments) > $last) { + if($base_segments[0] !== $iri_segments[0]) { + break; + } + array_shift($base_segments); + array_shift($iri_segments); + } + + // use '../' for each non-matching base segment + $rval = ''; + if(count($base_segments) > 0) { + // don't count the last segment (if it ends with '/' last path doesn't + // count and if it doesn't end with '/' it isn't a path) + array_pop($base_segments); + foreach($base_segments as $segment) { + $rval .= '../'; + } + } + + // prepend remaining segments + $rval .= implode('/', $iri_segments); + + // add query and hash + if($rel['query'] !== null) { + $rval .= "?{$rel['query']}"; + } + if($rel['fragment'] !== null) { + $rval .= "#{$rel['fragment']}"; + } + + if($rval === '') { + $rval = './'; + } + + return $rval; +} + + +/** + * A JSON-LD processor. + */ +class JsonLdProcessor { + /** XSD constants */ + const XSD_BOOLEAN = 'http://www.w3.org/2001/XMLSchema#boolean'; + const XSD_DOUBLE = 'http://www.w3.org/2001/XMLSchema#double'; + const XSD_INTEGER = 'http://www.w3.org/2001/XMLSchema#integer'; + const XSD_STRING = 'http://www.w3.org/2001/XMLSchema#string'; + + /** RDF constants */ + const RDF_LIST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#List'; + const RDF_FIRST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#first'; + const RDF_REST = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#rest'; + const RDF_NIL = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#nil'; + const RDF_TYPE = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type'; + const RDF_LANGSTRING = + 'http://www.w3.org/1999/02/22-rdf-syntax-ns#langString'; + + /** Restraints */ + const MAX_CONTEXT_URLS = 10; + + /** Processor-specific RDF dataset parsers. */ + protected $rdfParsers = null; + + /** + * Constructs a JSON-LD processor. + */ + public function __construct() {} + + /** + * Performs JSON-LD compaction. + * + * @param mixed $input the JSON-LD object to compact. + * @param mixed $ctx the context to compact with. + * @param assoc $options the compaction options. + * [base] the base IRI to use. + * [compactArrays] true to compact arrays to single values when + * appropriate, false not to (default: true). + * [graph] true to always output a top-level graph (default: false). + * [skipExpansion] true to assume the input is expanded and skip + * expansion, false not to, defaults to false. + * [activeCtx] true to also return the active context used. + * [documentLoader(url)] the document loader. + * + * @return mixed the compacted JSON-LD output. + */ + public function compact($input, $ctx, $options) { + global $jsonld_default_load_document; + + if($ctx === null) { + throw new JsonLdException( + 'The compaction context must not be null.', + 'jsonld.CompactError', 'invalid local context'); + } + + // nothing to compact + if($input === null) { + return null; + } + + self::setdefaults($options, array( + 'base' => is_string($input) ? $input : '', + 'compactArrays' => true, + 'graph' => false, + 'skipExpansion' => false, + 'activeCtx' => false, + 'documentLoader' => $jsonld_default_load_document, + 'link' => false)); + if($options['link']) { + // force skip expansion when linking, "link" is not part of the + // public API, it should only be called from framing + $options['skipExpansion'] = true; + } + + if($options['skipExpansion'] === true) { + $expanded = $input; + } else { + // expand input + try { + $expanded = $this->expand($input, $options); + } catch(JsonLdException $e) { + throw new JsonLdException( + 'Could not expand input before compaction.', + 'jsonld.CompactError', null, null, $e); + } + } + + // process context + $active_ctx = $this->_getInitialContext($options); + try { + $active_ctx = $this->processContext($active_ctx, $ctx, $options); + } catch(JsonLdException $e) { + throw new JsonLdException( + 'Could not process context before compaction.', + 'jsonld.CompactError', null, null, $e); + } + + // do compaction + $compacted = $this->_compact($active_ctx, null, $expanded, $options); + + if($options['compactArrays'] && + !$options['graph'] && is_array($compacted)) { + if(count($compacted) === 1) { + // simplify to a single item + $compacted = $compacted[0]; + } else if(count($compacted) === 0) { + // simplify to an empty object + $compacted = new stdClass(); + } + } else if($options['graph']) { + // always use array if graph option is on + $compacted = self::arrayify($compacted); + } + + // follow @context key + if(is_object($ctx) && property_exists($ctx, '@context')) { + $ctx = $ctx->{'@context'}; + } + + // build output context + $ctx = self::copy($ctx); + $ctx = self::arrayify($ctx); + + // remove empty contexts + $tmp = $ctx; + $ctx = array(); + foreach($tmp as $v) { + if(!is_object($v) || count(array_keys((array)$v)) > 0) { + $ctx[] = $v; + } + } + + // remove array if only one context + $ctx_length = count($ctx); + $has_context = ($ctx_length > 0); + if($ctx_length === 1) { + $ctx = $ctx[0]; + } + + // add context and/or @graph + if(is_array($compacted)) { + // use '@graph' keyword + $kwgraph = $this->_compactIri($active_ctx, '@graph'); + $graph = $compacted; + $compacted = new stdClass(); + if($has_context) { + $compacted->{'@context'} = $ctx; + } + $compacted->{$kwgraph} = $graph; + } else if(is_object($compacted) && $has_context) { + // reorder keys so @context is first + $graph = $compacted; + $compacted = new stdClass(); + $compacted->{'@context'} = $ctx; + foreach($graph as $k => $v) { + $compacted->{$k} = $v; + } + } + + if($options['activeCtx']) { + return array('compacted' => $compacted, 'activeCtx' => $active_ctx); + } + + return $compacted; + } + + /** + * Performs JSON-LD expansion. + * + * @param mixed $input the JSON-LD object to expand. + * @param assoc $options the options to use: + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [keepFreeFloatingNodes] true to keep free-floating nodes, + * false not to, defaults to false. + * [documentLoader(url)] the document loader. + * + * @return array the expanded JSON-LD output. + */ + public function expand($input, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'keepFreeFloatingNodes' => false, + 'documentLoader' => $jsonld_default_load_document)); + + // if input is a string, attempt to dereference remote document + if(is_string($input)) { + $remote_doc = call_user_func($options['documentLoader'], $input); + } else { + $remote_doc = (object)array( + 'contextUrl' => null, + 'documentUrl' => null, + 'document' => $input); + } + + try { + if($remote_doc->document === null) { + throw new JsonLdException( + 'No remote document found at the given URL.', + 'jsonld.NullRemoteDocument'); + } + if(is_string($remote_doc->document)) { + $remote_doc->document = self::_parse_json($remote_doc->document); + } + } catch(Exception $e) { + throw new JsonLdException( + 'Could not retrieve a JSON-LD document from the URL.', + 'jsonld.LoadDocumentError', 'loading document failed', + array('remoteDoc' => $remote_doc), $e); + } + + // set default base + self::setdefault($options, 'base', $remote_doc->documentUrl ?: ''); + + // build meta-object and retrieve all @context urls + $input = (object)array( + 'document' => self::copy($remote_doc->document), + 'remoteContext' => (object)array( + '@context' => $remote_doc->contextUrl)); + if(isset($options['expandContext'])) { + $expand_context = self::copy($options['expandContext']); + if(is_object($expand_context) && + property_exists($expand_context, '@context')) { + $input->expandContext = $expand_context; + } else { + $input->expandContext = (object)array('@context' => $expand_context); + } + } + + // retrieve all @context URLs in the input + try { + $this->_retrieveContextUrls( + $input, new stdClass(), $options['documentLoader'], $options['base']); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not perform JSON-LD expansion.', + 'jsonld.ExpandError', null, null, $e); + } + + $active_ctx = $this->_getInitialContext($options); + $document = $input->document; + $remote_context = $input->remoteContext->{'@context'}; + + // process optional expandContext + if(property_exists($input, 'expandContext')) { + $active_ctx = self::_processContext( + $active_ctx, $input->expandContext, $options); + } + + // process remote context from HTTP Link Header + if($remote_context) { + $active_ctx = self::_processContext( + $active_ctx, $remote_context, $options); + } + + // do expansion + $expanded = $this->_expand($active_ctx, null, $document, $options, false); + + // optimize away @graph with no other properties + if(is_object($expanded) && property_exists($expanded, '@graph') && + count(array_keys((array)$expanded)) === 1) { + $expanded = $expanded->{'@graph'}; + } else if($expanded === null) { + $expanded = array(); + } + // normalize to an array + return self::arrayify($expanded); + } + + /** + * Performs JSON-LD flattening. + * + * @param mixed $input the JSON-LD to flatten. + * @param ctx the context to use to compact the flattened output, or null. + * @param assoc $options the options to use: + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [documentLoader(url)] the document loader. + * + * @return array the flattened output. + */ + public function flatten($input, $ctx, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'base' => is_string($input) ? $input : '', + 'documentLoader' => $jsonld_default_load_document)); + + try { + // expand input + $expanded = $this->expand($input, $options); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not expand input before flattening.', + 'jsonld.FlattenError', null, null, $e); + } + + // do flattening + $flattened = $this->_flatten($expanded); + + if($ctx === null) { + return $flattened; + } + + // compact result (force @graph option to true, skip expansion) + $options['graph'] = true; + $options['skipExpansion'] = true; + try { + $compacted = $this->compact($flattened, $ctx, $options); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not compact flattened output.', + 'jsonld.FlattenError', null, null, $e); + } + + return $compacted; + } + + /** + * Performs JSON-LD framing. + * + * @param mixed $input the JSON-LD object to frame. + * @param stdClass $frame the JSON-LD frame to use. + * @param $options the framing options. + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [embed] default @embed flag: '@last', '@always', '@never', '@link' + * (default: '@last'). + * [explicit] default @explicit flag (default: false). + * [requireAll] default @requireAll flag (default: true). + * [omitDefault] default @omitDefault flag (default: false). + * [documentLoader(url)] the document loader. + * + * @return stdClass the framed JSON-LD output. + */ + public function frame($input, $frame, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'base' => is_string($input) ? $input : '', + 'compactArrays' => true, + 'embed' => '@last', + 'explicit' => false, + 'requireAll' => true, + 'omitDefault' => false, + 'documentLoader' => $jsonld_default_load_document)); + + // if frame is a string, attempt to dereference remote document + if(is_string($frame)) { + $remote_frame = call_user_func($options['documentLoader'], $frame); + } else { + $remote_frame = (object)array( + 'contextUrl' => null, + 'documentUrl' => null, + 'document' => $frame); + } + + try { + if($remote_frame->document === null) { + throw new JsonLdException( + 'No remote document found at the given URL.', + 'jsonld.NullRemoteDocument'); + } + if(is_string($remote_frame->document)) { + $remote_frame->document = self::_parse_json($remote_frame->document); + } + } catch(Exception $e) { + throw new JsonLdException( + 'Could not retrieve a JSON-LD document from the URL.', + 'jsonld.LoadDocumentError', 'loading document failed', + array('remoteDoc' => $remote_frame), $e); + } + + // preserve frame context + $frame = $remote_frame->document; + if($frame !== null) { + $ctx = (property_exists($frame, '@context') ? + $frame->{'@context'} : new stdClass()); + if($remote_frame->contextUrl !== null) { + if($ctx !== null) { + $ctx = $remote_frame->contextUrl; + } else { + $ctx = self::arrayify($ctx); + $ctx[] = $remote_frame->contextUrl; + } + $frame->{'@context'} = $ctx; + } + } + + try { + // expand input + $expanded = $this->expand($input, $options); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not expand input before framing.', + 'jsonld.FrameError', null, null, $e); + } + + try { + // expand frame + $opts = $options; + $opts['keepFreeFloatingNodes'] = true; + $expanded_frame = $this->expand($frame, $opts); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not expand frame before framing.', + 'jsonld.FrameError', null, null, $e); + } + + // do framing + $framed = $this->_frame($expanded, $expanded_frame, $options); + + try { + // compact result (force @graph option to true, skip expansion, check + // for linked embeds) + $options['graph'] = true; + $options['skipExpansion'] = true; + $options['link'] = new ArrayObject(); + $options['activeCtx'] = true; + $result = $this->compact($framed, $ctx, $options); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not compact framed output.', + 'jsonld.FrameError', null, null, $e); + } + + $compacted = $result['compacted']; + $active_ctx = $result['activeCtx']; + + // get graph alias + $graph = $this->_compactIri($active_ctx, '@graph'); + // remove @preserve from results + $options['link'] = new ArrayObject(); + $compacted->{$graph} = $this->_removePreserve( + $active_ctx, $compacted->{$graph}, $options); + return $compacted; + } + + /** + * Performs JSON-LD normalization. + * + * @param mixed $input the JSON-LD object to normalize. + * @param assoc $options the options to use: + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [inputFormat] the format if input is not JSON-LD: + * 'application/nquads' for N-Quads. + * [format] the format if output is a string: + * 'application/nquads' for N-Quads. + * [documentLoader(url)] the document loader. + * + * @return mixed the normalized output. + */ + public function normalize($input, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'base' => is_string($input) ? $input : '', + 'documentLoader' => $jsonld_default_load_document)); + + if(isset($options['inputFormat'])) { + if($options['inputFormat'] != 'application/nquads') { + throw new JsonLdException( + 'Unknown normalization input format.', 'jsonld.NormalizeError'); + } + $dataset = $this->parseNQuads($input); + } else { + try { + // convert to RDF dataset then do normalization + $opts = $options; + if(isset($opts['format'])) { + unset($opts['format']); + } + $opts['produceGeneralizedRdf'] = false; + $dataset = $this->toRDF($input, $opts); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not convert input to RDF dataset before normalization.', + 'jsonld.NormalizeError', null, null, $e); + } + } + + // do normalization + return $this->_normalize($dataset, $options); + } + + /** + * Converts an RDF dataset to JSON-LD. + * + * @param mixed $dataset a serialized string of RDF in a format specified + * by the format option or an RDF dataset to convert. + * @param assoc $options the options to use: + * [format] the format if input is a string: + * 'application/nquads' for N-Quads (default). + * [useRdfType] true to use rdf:type, false to use @type + * (default: false). + * [useNativeTypes] true to convert XSD types into native types + * (boolean, integer, double), false not to (default: false). + * + * @return array the JSON-LD output. + */ + public function fromRDF($dataset, $options) { + global $jsonld_rdf_parsers; + + self::setdefaults($options, array( + 'useRdfType' => false, + 'useNativeTypes' => false)); + + if(!isset($options['format']) && is_string($dataset)) { + // set default format to nquads + $options['format'] = 'application/nquads'; + } + + // handle special format + if(isset($options['format']) && $options['format']) { + // supported formats (processor-specific and global) + if(($this->rdfParsers !== null && + !property_exists($this->rdfParsers, $options['format'])) || + $this->rdfParsers === null && + !property_exists($jsonld_rdf_parsers, $options['format'])) { + throw new JsonLdException( + 'Unknown input format.', + 'jsonld.UnknownFormat', null, array('format' => $options['format'])); + } + if($this->rdfParsers !== null) { + $callable = $this->rdfParsers->{$options['format']}; + } else { + $callable = $jsonld_rdf_parsers->{$options['format']}; + } + $dataset = call_user_func($callable, $dataset); + } + + // convert from RDF + return $this->_fromRDF($dataset, $options); + } + + /** + * Outputs the RDF dataset found in the given JSON-LD object. + * + * @param mixed $input the JSON-LD object. + * @param assoc $options the options to use: + * [base] the base IRI to use. + * [expandContext] a context to expand with. + * [format] the format to use to output a string: + * 'application/nquads' for N-Quads. + * [produceGeneralizedRdf] true to output generalized RDF, false + * to produce only standard RDF (default: false). + * [documentLoader(url)] the document loader. + * + * @return mixed the resulting RDF dataset (or a serialization of it). + */ + public function toRDF($input, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'base' => is_string($input) ? $input : '', + 'produceGeneralizedRdf' => false, + 'documentLoader' => $jsonld_default_load_document)); + + try { + // expand input + $expanded = $this->expand($input, $options); + } catch(JsonLdException $e) { + throw new JsonLdException( + 'Could not expand input before serialization to RDF.', + 'jsonld.RdfError', null, null, $e); + } + + // create node map for default graph (and any named graphs) + $namer = new UniqueNamer('_:b'); + $node_map = (object)array('@default' => new stdClass()); + $this->_createNodeMap($expanded, $node_map, '@default', $namer); + + // output RDF dataset + $dataset = new stdClass(); + $graph_names = array_keys((array)$node_map); + sort($graph_names); + foreach($graph_names as $graph_name) { + $graph = $node_map->{$graph_name}; + // skip relative IRIs + if($graph_name === '@default' || self::_isAbsoluteIri($graph_name)) { + $dataset->{$graph_name} = $this->_graphToRDF($graph, $namer, $options); + } + } + + $rval = $dataset; + + // convert to output format + if(isset($options['format']) && $options['format']) { + // supported formats + if($options['format'] === 'application/nquads') { + $rval = self::toNQuads($dataset); + } else { + throw new JsonLdException( + 'Unknown output format.', 'jsonld.UnknownFormat', + null, array('format' => $options['format'])); + } + } + + return $rval; + } + + /** + * Processes a local context, resolving any URLs as necessary, and returns a + * new active context in its callback. + * + * @param stdClass $active_ctx the current active context. + * @param mixed $local_ctx the local context to process. + * @param assoc $options the options to use: + * [documentLoader(url)] the document loader. + * + * @return stdClass the new active context. + */ + public function processContext($active_ctx, $local_ctx, $options) { + global $jsonld_default_load_document; + self::setdefaults($options, array( + 'base' => '', + 'documentLoader' => $jsonld_default_load_document)); + + // return initial context early for null context + if($local_ctx === null) { + return $this->_getInitialContext($options); + } + + // retrieve URLs in local_ctx + $local_ctx = self::copy($local_ctx); + if(is_string($local_ctx) or ( + is_object($local_ctx) && !property_exists($local_ctx, '@context'))) { + $local_ctx = (object)array('@context' => $local_ctx); + } + try { + $this->_retrieveContextUrls( + $local_ctx, new stdClass(), + $options['documentLoader'], $options['base']); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not process JSON-LD context.', + 'jsonld.ContextError', null, null, $e); + } + + // process context + return $this->_processContext($active_ctx, $local_ctx, $options); + } + + /** + * Returns true if the given subject has the given property. + * + * @param stdClass $subject the subject to check. + * @param string $property the property to look for. + * + * @return bool true if the subject has the given property, false if not. + */ + public static function hasProperty($subject, $property) { + $rval = false; + if(property_exists($subject, $property)) { + $value = $subject->{$property}; + $rval = (!is_array($value) || count($value) > 0); + } + return $rval; + } + + /** + * Determines if the given value is a property of the given subject. + * + * @param stdClass $subject the subject to check. + * @param string $property the property to check. + * @param mixed $value the value to check. + * + * @return bool true if the value exists, false if not. + */ + public static function hasValue($subject, $property, $value) { + $rval = false; + if(self::hasProperty($subject, $property)) { + $val = $subject->{$property}; + $is_list = self::_isList($val); + if(is_array($val) || $is_list) { + if($is_list) { + $val = $val->{'@list'}; + } + foreach($val as $v) { + if(self::compareValues($value, $v)) { + $rval = true; + break; + } + } + } else if(!is_array($value)) { + // avoid matching the set of values with an array value parameter + $rval = self::compareValues($value, $val); + } + } + return $rval; + } + + /** + * Adds a value to a subject. If the value is an array, all values in the + * array will be added. + * + * Note: If the value is a subject that already exists as a property of the + * given subject, this method makes no attempt to deeply merge properties. + * Instead, the value will not be added. + * + * @param stdClass $subject the subject to add the value to. + * @param string $property the property that relates the value to the subject. + * @param mixed $value the value to add. + * @param assoc [$options] the options to use: + * [propertyIsArray] true if the property is always an array, false + * if not (default: false). + * [allowDuplicate] true to allow duplicates, false not to (uses a + * simple shallow comparison of subject ID or value) + * (default: true). + */ + public static function addValue( + $subject, $property, $value, $options=array()) { + self::setdefaults($options, array( + 'allowDuplicate' => true, + 'propertyIsArray' => false)); + + if(is_array($value)) { + if(count($value) === 0 && $options['propertyIsArray'] && + !property_exists($subject, $property)) { + $subject->{$property} = array(); + } + foreach($value as $v) { + self::addValue($subject, $property, $v, $options); + } + } else if(property_exists($subject, $property)) { + // check if subject already has value if duplicates not allowed + $has_value = (!$options['allowDuplicate'] && + self::hasValue($subject, $property, $value)); + + // make property an array if value not present or always an array + if(!is_array($subject->{$property}) && + (!$has_value || $options['propertyIsArray'])) { + $subject->{$property} = array($subject->{$property}); + } + + // add new value + if(!$has_value) { + $subject->{$property}[] = $value; + } + } else { + // add new value as set or single value + $subject->{$property} = ($options['propertyIsArray'] ? + array($value) : $value); + } + } + + /** + * Gets all of the values for a subject's property as an array. + * + * @param stdClass $subject the subject. + * @param string $property the property. + * + * @return array all of the values for a subject's property as an array. + */ + public static function getValues($subject, $property) { + $rval = (property_exists($subject, $property) ? + $subject->{$property} : array()); + return self::arrayify($rval); + } + + /** + * Removes a property from a subject. + * + * @param stdClass $subject the subject. + * @param string $property the property. + */ + public static function removeProperty($subject, $property) { + unset($subject->{$property}); + } + + /** + * Removes a value from a subject. + * + * @param stdClass $subject the subject. + * @param string $property the property that relates the value to the subject. + * @param mixed $value the value to remove. + * @param assoc [$options] the options to use: + * [propertyIsArray] true if the property is always an array, + * false if not (default: false). + */ + public static function removeValue( + $subject, $property, $value, $options=array()) { + self::setdefaults($options, array( + 'propertyIsArray' => false)); + + // filter out value + $filter = function($e) use ($value) { + return !self::compareValues($e, $value); + }; + $values = self::getValues($subject, $property); + $values = array_values(array_filter($values, $filter)); + + if(count($values) === 0) { + self::removeProperty($subject, $property); + } else if(count($values) === 1 && !$options['propertyIsArray']) { + $subject->{$property} = $values[0]; + } else { + $subject->{$property} = $values; + } + } + + /** + * Compares two JSON-LD values for equality. Two JSON-LD values will be + * considered equal if: + * + * 1. They are both primitives of the same type and value. + * 2. They are both @values with the same @value, @type, @language, + * and @index, OR + * 3. They both have @ids that are the same. + * + * @param mixed $v1 the first value. + * @param mixed $v2 the second value. + * + * @return bool true if v1 and v2 are considered equal, false if not. + */ + public static function compareValues($v1, $v2) { + // 1. equal primitives + if($v1 === $v2) { + return true; + } + + // 2. equal @values + if(self::_isValue($v1) && self::_isValue($v2)) { + return ( + self::_compareKeyValues($v1, $v2, '@value') && + self::_compareKeyValues($v1, $v2, '@type') && + self::_compareKeyValues($v1, $v2, '@language') && + self::_compareKeyValues($v1, $v2, '@index')); + } + + // 3. equal @ids + if(is_object($v1) && property_exists($v1, '@id') && + is_object($v2) && property_exists($v2, '@id')) { + return $v1->{'@id'} === $v2->{'@id'}; + } + + return false; + } + + /** + * Gets the value for the given active context key and type, null if none is + * set. + * + * @param stdClass $ctx the active context. + * @param string $key the context key. + * @param string [$type] the type of value to get (eg: '@id', '@type'), if not + * specified gets the entire entry for a key, null if not found. + * + * @return mixed the value. + */ + public static function getContextValue($ctx, $key, $type) { + $rval = null; + + // return null for invalid key + if($key === null) { + return $rval; + } + + // get default language + if($type === '@language' && property_exists($ctx, $type)) { + $rval = $ctx->{$type}; + } + + // get specific entry information + if(property_exists($ctx->mappings, $key)) { + $entry = $ctx->mappings->{$key}; + if($entry === null) { + return null; + } + + if($type === null) { + // return whole entry + $rval = $entry; + } else if(property_exists($entry, $type)) { + // return entry value for type + $rval = $entry->{$type}; + } + } + + return $rval; + } + + /** + * Parses RDF in the form of N-Quads. + * + * @param string $input the N-Quads input to parse. + * + * @return stdClass an RDF dataset. + */ + public static function parseNQuads($input) { + // define partial regexes + $iri = '(?:<([^:]+:[^>]*)>)'; + $bnode = '(_:(?:[A-Za-z][A-Za-z0-9]*))'; + $plain = '"([^"\\\\]*(?:\\\\.[^"\\\\]*)*)"'; + $datatype = "(?:\\^\\^$iri)"; + $language = '(?:@([a-z]+(?:-[a-z0-9]+)*))'; + $literal = "(?:$plain(?:$datatype|$language)?)"; + $ws = '[ \\t]'; + $eoln = '/(?:\r\n)|(?:\n)|(?:\r)/'; + $empty = "/^$ws*$/"; + + // define quad part regexes + $subject = "(?:$iri|$bnode)$ws+"; + $property = "$iri$ws+"; + $object = "(?:$iri|$bnode|$literal)$ws*"; + $graph_name = "(?:\\.|(?:(?:$iri|$bnode)$ws*\\.))"; + + // full quad regex + $quad = "/^$ws*$subject$property$object$graph_name$ws*$/"; + + // build RDF dataset + $dataset = new stdClass(); + + // split N-Quad input into lines + $lines = preg_split($eoln, $input); + $line_number = 0; + foreach($lines as $line) { + $line_number += 1; + + // skip empty lines + if(preg_match($empty, $line)) { + continue; + } + + // parse quad + if(!preg_match($quad, $line, $match)) { + throw new JsonLdException( + 'Error while parsing N-Quads; invalid quad.', + 'jsonld.ParseError', null, array('line' => $line_number)); + } + + // create RDF triple + $triple = (object)array( + 'subject' => new stdClass(), + 'predicate' => new stdClass(), + 'object' => new stdClass()); + + // get subject + if($match[1] !== '') { + $triple->subject->type = 'IRI'; + $triple->subject->value = $match[1]; + } else { + $triple->subject->type = 'blank node'; + $triple->subject->value = $match[2]; + } + + // get predicate + $triple->predicate->type = 'IRI'; + $triple->predicate->value = $match[3]; + + // get object + if($match[4] !== '') { + $triple->object->type = 'IRI'; + $triple->object->value = $match[4]; + } else if($match[5] !== '') { + $triple->object->type = 'blank node'; + $triple->object->value = $match[5]; + } else { + $triple->object->type = 'literal'; + $unescaped = str_replace( + array('\"', '\t', '\n', '\r', '\\\\'), + array('"', "\t", "\n", "\r", '\\'), + $match[6]); + if(isset($match[7]) && $match[7] !== '') { + $triple->object->datatype = $match[7]; + } else if(isset($match[8]) && $match[8] !== '') { + $triple->object->datatype = self::RDF_LANGSTRING; + $triple->object->language = $match[8]; + } else { + $triple->object->datatype = self::XSD_STRING; + } + $triple->object->value = $unescaped; + } + + // get graph name ('@default' is used for the default graph) + $name = '@default'; + if(isset($match[9]) && $match[9] !== '') { + $name = $match[9]; + } else if(isset($match[10]) && $match[10] !== '') { + $name = $match[10]; + } + + // initialize graph in dataset + if(!property_exists($dataset, $name)) { + $dataset->{$name} = array($triple); + } else { + // add triple if unique to its graph + $unique = true; + $triples = &$dataset->{$name}; + foreach($triples as $t) { + if(self::_compareRDFTriples($t, $triple)) { + $unique = false; + break; + } + } + if($unique) { + $triples[] = $triple; + } + } + } + + return $dataset; + } + + /** + * Converts an RDF dataset to N-Quads. + * + * @param stdClass $dataset the RDF dataset to convert. + * + * @return string the N-Quads string. + */ + public static function toNQuads($dataset) { + $quads = array(); + foreach($dataset as $graph_name => $triples) { + foreach($triples as $triple) { + if($graph_name === '@default') { + $graph_name = null; + } + $quads[] = self::toNQuad($triple, $graph_name); + } + } + sort($quads); + return implode($quads); + } + + /** + * Converts an RDF triple and graph name to an N-Quad string (a single quad). + * + * @param stdClass $triple the RDF triple to convert. + * @param mixed $graph_name the name of the graph containing the triple, null + * for the default graph. + * @param string $bnode the bnode the quad is mapped to (optional, for + * use during normalization only). + * + * @return string the N-Quad string. + */ + public static function toNQuad($triple, $graph_name, $bnode=null) { + $s = $triple->subject; + $p = $triple->predicate; + $o = $triple->object; + $g = $graph_name; + + $quad = ''; + + // subject is an IRI + if($s->type === 'IRI') { + $quad .= "<{$s->value}>"; + } else if($bnode !== null) { + // bnode normalization mode + $quad .= ($s->value === $bnode) ? '_:a' : '_:z'; + } else { + // bnode normal mode + $quad .= $s->value; + } + $quad .= ' '; + + // predicate is an IRI + if($p->type === 'IRI') { + $quad .= "<{$p->value}>"; + } else if($bnode !== null) { + // FIXME: TBD what to do with bnode predicates during normalization + // bnode normalization mode + $quad .= '_:p'; + } else { + // bnode normal mode + $quad .= $p->value; + } + $quad .= ' '; + + // object is IRI, bnode, or literal + if($o->type === 'IRI') { + $quad .= "<{$o->value}>"; + } else if($o->type === 'blank node') { + if($bnode !== null) { + // normalization mode + $quad .= ($o->value === $bnode) ? '_:a' : '_:z'; + } else { + // normal mode + $quad .= $o->value; + } + } else { + $escaped = str_replace( + array('\\', "\t", "\n", "\r", '"'), + array('\\\\', '\t', '\n', '\r', '\"'), + $o->value); + $quad .= '"' . $escaped . '"'; + if($o->datatype === self::RDF_LANGSTRING) { + if($o->language) { + $quad .= "@{$o->language}"; + } + } else if($o->datatype !== self::XSD_STRING) { + $quad .= "^^<{$o->datatype}>"; + } + } + + // graph + if($g !== null) { + if(strpos($g, '_:') !== 0) { + $quad .= " <$g>"; + } else if($bnode) { + $quad .= ' _:g'; + } else { + $quad .= " $g"; + } + } + + $quad .= " .\n"; + return $quad; + } + + /** + * Registers a processor-specific RDF dataset parser by content-type. + * Global parsers will no longer be used by this processor. + * + * @param string $content_type the content-type for the parser. + * @param callable $parser(input) the parser function (takes a string as + * a parameter and returns an RDF dataset). + */ + public function registerRDFParser($content_type, $parser) { + if($this->rdfParsers === null) { + $this->rdfParsers = new stdClass(); + } + $this->rdfParsers->{$content_type} = $parser; + } + + /** + * Unregisters a process-specific RDF dataset parser by content-type. If + * there are no remaining processor-specific parsers, then the global + * parsers will be re-enabled. + * + * @param string $content_type the content-type for the parser. + */ + public function unregisterRDFParser($content_type) { + if($this->rdfParsers !== null && + property_exists($this->rdfParsers, $content_type)) { + unset($this->rdfParsers->{$content_type}); + if(count(get_object_vars($content_type)) === 0) { + $this->rdfParsers = null; + } + } + } + + /** + * If $value is an array, returns $value, otherwise returns an array + * containing $value as the only element. + * + * @param mixed $value the value. + * + * @return array an array. + */ + public static function arrayify($value) { + return is_array($value) ? $value : array($value); + } + + /** + * Clones an object, array, or string/number. + * + * @param mixed $value the value to clone. + * + * @return mixed the cloned value. + */ + public static function copy($value) { + if(is_object($value) || is_array($value)) { + return unserialize(serialize($value)); + } + return $value; + } + + /** + * Sets the value of a key for the given array if that property + * has not already been set. + * + * @param &assoc $arr the object to update. + * @param string $key the key to update. + * @param mixed $value the value to set. + */ + public static function setdefault(&$arr, $key, $value) { + isset($arr[$key]) or $arr[$key] = $value; + } + + /** + * Sets default values for keys in the given array. + * + * @param &assoc $arr the object to update. + * @param assoc $defaults the default keys and values. + */ + public static function setdefaults(&$arr, $defaults) { + foreach($defaults as $key => $value) { + self::setdefault($arr, $key, $value); + } + } + + /** + * Recursively compacts an element using the given active context. All values + * must be in expanded form before this method is called. + * + * @param stdClass $active_ctx the active context to use. + * @param mixed $active_property the compacted property with the element + * to compact, null for none. + * @param mixed $element the element to compact. + * @param assoc $options the compaction options. + * + * @return mixed the compacted value. + */ + protected function _compact( + $active_ctx, $active_property, $element, $options) { + // recursively compact array + if(is_array($element)) { + $rval = array(); + foreach($element as $e) { + // compact, dropping any null values + $compacted = $this->_compact( + $active_ctx, $active_property, $e, $options); + if($compacted !== null) { + $rval[] = $compacted; + } + } + if($options['compactArrays'] && count($rval) === 1) { + // use single element if no container is specified + $container = self::getContextValue( + $active_ctx, $active_property, '@container'); + if($container === null) { + $rval = $rval[0]; + } + } + return $rval; + } + + // recursively compact object + if(is_object($element)) { + if($options['link'] && property_exists($element, '@id') && + isset($options['link'][$element->{'@id'}])) { + // check for a linked element to reuse + $linked = $options['link'][$element->{'@id'}]; + foreach($linked as $link) { + if($link['expanded'] === $element) { + return $link['compacted']; + } + } + } + + // do value compaction on @values and subject references + if(self::_isValue($element) || self::_isSubjectReference($element)) { + $rval = $this->_compactValue($active_ctx, $active_property, $element); + if($options['link'] && self::_isSubjectReference($element)) { + // store linked element + if(!isset($options['link'][$element->{'@id'}])) { + $options['link'][$element->{'@id'}] = array(); + } + $options['link'][$element->{'@id'}][] = array( + 'expanded' => $element, 'compacted' => $rval); + } + return $rval; + } + + // FIXME: avoid misuse of active property as an expanded property? + $inside_reverse = ($active_property === '@reverse'); + + $rval = new stdClass(); + + if($options['link'] && property_exists($element, '@id')) { + // store linked element + if(!isset($options['link'][$element->{'@id'}])) { + $options['link'][$element->{'@id'}] = array(); + } + $options['link'][$element->{'@id'}][] = array( + 'expanded' => $element, 'compacted' => $rval); + } + + // process element keys in order + $keys = array_keys((array)$element); + sort($keys); + foreach($keys as $expanded_property) { + $expanded_value = $element->{$expanded_property}; + + // compact @id and @type(s) + if($expanded_property === '@id' || $expanded_property === '@type') { + if(is_string($expanded_value)) { + // compact single @id + $compacted_value = $this->_compactIri( + $active_ctx, $expanded_value, null, + array('vocab' => ($expanded_property === '@type'))); + } else { + // expanded value must be a @type array + $compacted_value = array(); + foreach($expanded_value as $ev) { + $compacted_value[] = $this->_compactIri( + $active_ctx, $ev, null, array('vocab' => true)); + } + } + + // use keyword alias and add value + $alias = $this->_compactIri($active_ctx, $expanded_property); + $is_array = (is_array($compacted_value) && + count($expanded_value) === 0); + self::addValue( + $rval, $alias, $compacted_value, + array('propertyIsArray' => $is_array)); + continue; + } + + // handle @reverse + if($expanded_property === '@reverse') { + // recursively compact expanded value + $compacted_value = $this->_compact( + $active_ctx, '@reverse', $expanded_value, $options); + + // handle double-reversed properties + foreach($compacted_value as $compacted_property => $value) { + if(property_exists($active_ctx->mappings, $compacted_property) && + $active_ctx->mappings->{$compacted_property} && + $active_ctx->mappings->{$compacted_property}->reverse) { + $container = self::getContextValue( + $active_ctx, $compacted_property, '@container'); + $use_array = ($container === '@set' || + !$options['compactArrays']); + self::addValue( + $rval, $compacted_property, $value, + array('propertyIsArray' => $use_array)); + unset($compacted_value->{$compacted_property}); + } + } + + if(count(array_keys((array)$compacted_value)) > 0) { + // use keyword alias and add value + $alias = $this->_compactIri($active_ctx, $expanded_property); + self::addValue($rval, $alias, $compacted_value); + } + + continue; + } + + // handle @index property + if($expanded_property === '@index') { + // drop @index if inside an @index container + $container = self::getContextValue( + $active_ctx, $active_property, '@container'); + if($container === '@index') { + continue; + } + + // use keyword alias and add value + $alias = $this->_compactIri($active_ctx, $expanded_property); + self::addValue($rval, $alias, $expanded_value); + continue; + } + + // skip array processing for keywords that aren't @graph or @list + if($expanded_property !== '@graph' && $expanded_property !== '@list' && + self::_isKeyword($expanded_property)) { + // use keyword alias and add value as is + $alias = $this->_compactIri($active_ctx, $expanded_property); + self::addValue($rval, $alias, $expanded_value); + continue; + } + + // Note: expanded value must be an array due to expansion algorithm. + + // preserve empty arrays + if(count($expanded_value) === 0) { + $item_active_property = $this->_compactIri( + $active_ctx, $expanded_property, $expanded_value, + array('vocab' => true), $inside_reverse); + self::addValue( + $rval, $item_active_property, array(), + array('propertyIsArray' => true)); + } + + // recusively process array values + foreach($expanded_value as $expanded_item) { + // compact property and get container type + $item_active_property = $this->_compactIri( + $active_ctx, $expanded_property, $expanded_item, + array('vocab' => true), $inside_reverse); + $container = self::getContextValue( + $active_ctx, $item_active_property, '@container'); + + // get @list value if appropriate + $is_list = self::_isList($expanded_item); + $list = null; + if($is_list) { + $list = $expanded_item->{'@list'}; + } + + // recursively compact expanded item + $compacted_item = $this->_compact( + $active_ctx, $item_active_property, + $is_list ? $list : $expanded_item, $options); + + // handle @list + if($is_list) { + // ensure @list value is an array + $compacted_item = self::arrayify($compacted_item); + + if($container !== '@list') { + // wrap using @list alias + $compacted_item = (object)array( + $this->_compactIri($active_ctx, '@list') => $compacted_item); + + // include @index from expanded @list, if any + if(property_exists($expanded_item, '@index')) { + $compacted_item->{$this->_compactIri($active_ctx, '@index')} = + $expanded_item->{'@index'}; + } + } else if(property_exists($rval, $item_active_property)) { + // can't use @list container for more than 1 list + throw new JsonLdException( + 'JSON-LD compact error; property has a "@list" @container ' . + 'rule but there is more than a single @list that matches ' . + 'the compacted term in the document. Compaction might mix ' . + 'unwanted items into the list.', 'jsonld.SyntaxError', + 'compaction to list of lists'); + } + } + + // handle language and index maps + if($container === '@language' || $container === '@index') { + // get or create the map object + if(property_exists($rval, $item_active_property)) { + $map_object = $rval->{$item_active_property}; + } else { + $rval->{$item_active_property} = $map_object = new stdClass(); + } + + // if container is a language map, simplify compacted value to + // a simple string + if($container === '@language' && self::_isValue($compacted_item)) { + $compacted_item = $compacted_item->{'@value'}; + } + + // add compact value to map object using key from expanded value + // based on the container type + self::addValue( + $map_object, $expanded_item->{$container}, $compacted_item); + } else { + // use an array if: compactArrays flag is false, + // @container is @set or @list, value is an empty + // array, or key is @graph + $is_array = (!$options['compactArrays'] || + $container === '@set' || $container === '@list' || + (is_array($compacted_item) && count($compacted_item) === 0) || + $expanded_property === '@list' || + $expanded_property === '@graph'); + + // add compact value + self::addValue( + $rval, $item_active_property, $compacted_item, + array('propertyIsArray' => $is_array)); + } + } + } + + return $rval; + } + + // only primitives remain which are already compact + return $element; + } + + /** + * Recursively expands an element using the given context. Any context in + * the element will be removed. All context URLs must have been retrieved + * before calling this method. + * + * @param stdClass $active_ctx the active context to use. + * @param mixed $active_property the property for the element, null for none. + * @param mixed $element the element to expand. + * @param assoc $options the expansion options. + * @param bool $inside_list true if the property is a list, false if not. + * + * @return mixed the expanded value. + */ + protected function _expand( + $active_ctx, $active_property, $element, $options, $inside_list) { + // nothing to expand + if($element === null) { + return $element; + } + + // recursively expand array + if(is_array($element)) { + $rval = array(); + $container = self::getContextValue( + $active_ctx, $active_property, '@container'); + $inside_list = $inside_list || $container === '@list'; + foreach($element as $e) { + // expand element + $e = $this->_expand( + $active_ctx, $active_property, $e, $options, $inside_list); + if($inside_list && (is_array($e) || self::_isList($e))) { + // lists of lists are illegal + throw new JsonLdException( + 'Invalid JSON-LD syntax; lists of lists are not permitted.', + 'jsonld.SyntaxError', 'list of lists'); + } + // drop null values + if($e !== null) { + if(is_array($e)) { + $rval = array_merge($rval, $e); + } else { + $rval[] = $e; + } + } + } + return $rval; + } + + if(!is_object($element)) { + // drop free-floating scalars that are not in lists + if(!$inside_list && + ($active_property === null || + $this->_expandIri($active_ctx, $active_property, + array('vocab' => true)) === '@graph')) { + return null; + } + + // expand element according to value expansion rules + return $this->_expandValue($active_ctx, $active_property, $element); + } + + // recursively expand object: + + // if element has a context, process it + if(property_exists($element, '@context')) { + $active_ctx = $this->_processContext( + $active_ctx, $element->{'@context'}, $options); + } + + // expand the active property + $expanded_active_property = $this->_expandIri( + $active_ctx, $active_property, array('vocab' => true)); + + $rval = new stdClass(); + $keys = array_keys((array)$element); + sort($keys); + foreach($keys as $key) { + $value = $element->{$key}; + + if($key === '@context') { + continue; + } + + // expand key to IRI + $expanded_property = $this->_expandIri( + $active_ctx, $key, array('vocab' => true)); + + // drop non-absolute IRI keys that aren't keywords + if($expanded_property === null || + !(self::_isAbsoluteIri($expanded_property) || + self::_isKeyword($expanded_property))) { + continue; + } + + if(self::_isKeyword($expanded_property)) { + if($expanded_active_property === '@reverse') { + throw new JsonLdException( + 'Invalid JSON-LD syntax; a keyword cannot be used as a @reverse ' . + 'property.', 'jsonld.SyntaxError', 'invalid reverse property map', + array('value' => $value)); + } + if(property_exists($rval, $expanded_property)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; colliding keywords detected.', + 'jsonld.SyntaxError', 'colliding keywords', + array('keyword' => $expanded_property)); + } + } + + // syntax error if @id is not a string + if($expanded_property === '@id' && !is_string($value)) { + if(!isset($options['isFrame']) || !$options['isFrame']) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@id" value must a string.', + 'jsonld.SyntaxError', 'invalid @id value', + array('value' => $value)); + } + if(!is_object($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@id" value must a string or an object.', + 'jsonld.SyntaxError', 'invalid @id value', + array('value' => $value)); + } + } + + // validate @type value + if($expanded_property === '@type') { + $this->_validateTypeValue($value); + } + + // @graph must be an array or an object + if($expanded_property === '@graph' && + !(is_object($value) || is_array($value))) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@graph" value must not be an ' . + 'object or an array.', 'jsonld.SyntaxError', + 'invalid @graph value', array('value' => $value)); + } + + // @value must not be an object or an array + if($expanded_property === '@value' && + (is_object($value) || is_array($value))) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@value" value must not be an ' . + 'object or an array.', 'jsonld.SyntaxError', + 'invalid value object value', array('value' => $value)); + } + + // @language must be a string + if($expanded_property === '@language') { + if($value === null) { + // drop null @language values, they expand as if they didn't exist + continue; + } + if(!is_string($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@language" value must not be a string.', + 'jsonld.SyntaxError', 'invalid language-tagged string', + array('value' => $value)); + } + // ensure language value is lowercase + $value = strtolower($value); + } + + // @index must be a string + if($expanded_property === '@index') { + if(!is_string($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@index" value must be a string.', + 'jsonld.SyntaxError', 'invalid @index value', + array('value' => $value)); + } + } + + // @reverse must be an object + if($expanded_property === '@reverse') { + if(!is_object($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@reverse" value must be an object.', + 'jsonld.SyntaxError', 'invalid @reverse value', + array('value' => $value)); + } + + $expanded_value = $this->_expand( + $active_ctx, '@reverse', $value, $options, $inside_list); + + // properties double-reversed + if(property_exists($expanded_value, '@reverse')) { + foreach($expanded_value->{'@reverse'} as $rproperty => $rvalue) { + self::addValue( + $rval, $rproperty, $rvalue, array('propertyIsArray' => true)); + } + } + + // FIXME: can this be merged with code below to simplify? + // merge in all reversed properties + if(property_exists($rval, '@reverse')) { + $reverse_map = $rval->{'@reverse'}; + } else { + $reverse_map = null; + } + foreach($expanded_value as $property => $items) { + if($property === '@reverse') { + continue; + } + if($reverse_map === null) { + $reverse_map = $rval->{'@reverse'} = new stdClass(); + } + self::addValue( + $reverse_map, $property, array(), + array('propertyIsArray' => true)); + foreach($items as $item) { + if(self::_isValue($item) || self::_isList($item)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@reverse" value must not be a ' + + '@value or an @list.', 'jsonld.SyntaxError', + 'invalid reverse property value', + array('value' => $expanded_value)); + } + self::addValue( + $reverse_map, $property, $item, + array('propertyIsArray' => true)); + } + } + + continue; + } + + $container = self::getContextValue($active_ctx, $key, '@container'); + + if($container === '@language' && is_object($value)) { + // handle language map container (skip if value is not an object) + $expanded_value = $this->_expandLanguageMap($value); + } else if($container === '@index' && is_object($value)) { + // handle index container (skip if value is not an object) + $expanded_value = array(); + $value_keys = array_keys((array)$value); + sort($value_keys); + foreach($value_keys as $value_key) { + $val = $value->{$value_key}; + $val = self::arrayify($val); + $val = $this->_expand($active_ctx, $key, $val, $options, false); + foreach($val as $item) { + if(!property_exists($item, '@index')) { + $item->{'@index'} = $value_key; + } + $expanded_value[] = $item; + } + } + } else { + // recurse into @list or @set + $is_list = ($expanded_property === '@list'); + if($is_list || $expanded_property === '@set') { + $next_active_property = $active_property; + if($is_list && $expanded_active_property === '@graph') { + $next_active_property = null; + } + $expanded_value = $this->_expand( + $active_ctx, $next_active_property, $value, $options, $is_list); + if($is_list && self::_isList($expanded_value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; lists of lists are not permitted.', + 'jsonld.SyntaxError', 'list of lists'); + } + } else { + // recursively expand value with key as new active property + $expanded_value = $this->_expand( + $active_ctx, $key, $value, $options, false); + } + } + + // drop null values if property is not @value + if($expanded_value === null && $expanded_property !== '@value') { + continue; + } + + // convert expanded value to @list if container specifies it + if($expanded_property !== '@list' && !self::_isList($expanded_value) && + $container === '@list') { + // ensure expanded value is an array + $expanded_value = (object)array( + '@list' => self::arrayify($expanded_value)); + } + + // FIXME: can this be merged with code above to simplify? + // merge in reverse properties + if(property_exists($active_ctx->mappings, $key) && + $active_ctx->mappings->{$key} && + $active_ctx->mappings->{$key}->reverse) { + if(property_exists($rval, '@reverse')) { + $reverse_map = $rval->{'@reverse'}; + } else { + $reverse_map = $rval->{'@reverse'} = new stdClass(); + } + $expanded_value = self::arrayify($expanded_value); + foreach($expanded_value as $item) { + if(self::_isValue($item) || self::_isList($item)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@reverse" value must not be a ' + + '@value or an @list.', 'jsonld.SyntaxError', + 'invalid reverse property value', + array('value' => $expanded_value)); + } + self::addValue( + $reverse_map, $expanded_property, $item, + array('propertyIsArray' => true)); + } + continue; + } + + // add value for property + // use an array except for certain keywords + $use_array = (!in_array( + $expanded_property, array( + '@index', '@id', '@type', '@value', '@language'))); + self::addValue( + $rval, $expanded_property, $expanded_value, + array('propertyIsArray' => $use_array)); + } + + // get property count on expanded output + $keys = array_keys((array)$rval); + $count = count($keys); + + // @value must only have @language or @type + if(property_exists($rval, '@value')) { + // @value must only have @language or @type + if(property_exists($rval, '@type') && + property_exists($rval, '@language')) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; an element containing "@value" may not ' . + 'contain both "@type" and "@language".', + 'jsonld.SyntaxError', 'invalid value object', + array('element' => $rval)); + } + $valid_count = $count - 1; + if(property_exists($rval, '@type')) { + $valid_count -= 1; + } + if(property_exists($rval, '@index')) { + $valid_count -= 1; + } + if(property_exists($rval, '@language')) { + $valid_count -= 1; + } + if($valid_count !== 0) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; an element containing "@value" may only ' . + 'have an "@index" property and at most one other property ' . + 'which can be "@type" or "@language".', + 'jsonld.SyntaxError', 'invalid value object', + array('element' => $rval)); + } + // drop null @values + if($rval->{'@value'} === null) { + $rval = null; + } else if(property_exists($rval, '@language') && + !is_string($rval->{'@value'})) { + // if @language is present, @value must be a string + throw new JsonLdException( + 'Invalid JSON-LD syntax; only strings may be language-tagged.', + 'jsonld.SyntaxError', 'invalid language-tagged value', + array('element' => $rval)); + } else if(property_exists($rval, '@type') && + (!self::_isAbsoluteIri($rval->{'@type'}) || + strpos($rval->{'@type'}, '_:') === 0)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; an element containing "@value" ' . + 'and "@type" must have an absolute IRI for the value ' . + 'of "@type".', 'jsonld.SyntaxError', 'invalid typed value', + array('element' => $rval)); + } + } else if(property_exists($rval, '@type') && !is_array($rval->{'@type'})) { + // convert @type to an array + $rval->{'@type'} = array($rval->{'@type'}); + } else if(property_exists($rval, '@set') || + property_exists($rval, '@list')) { + // handle @set and @list + if($count > 1 && !($count === 2 && property_exists($rval, '@index'))) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; if an element has the property "@set" ' . + 'or "@list", then it can have at most one other property that is ' . + '"@index".', 'jsonld.SyntaxError', 'invalid set or list object', + array('element' => $rval)); + } + // optimize away @set + if(property_exists($rval, '@set')) { + $rval = $rval->{'@set'}; + $keys = array_keys((array)$rval); + $count = count($keys); + } + } else if($count === 1 && property_exists($rval, '@language')) { + // drop objects with only @language + $rval = null; + } + + // drop certain top-level objects that do not occur in lists + if(is_object($rval) && + !$options['keepFreeFloatingNodes'] && !$inside_list && + ($active_property === null || $expanded_active_property === '@graph')) { + // drop empty object or top-level @value/@list, or object with only @id + if($count === 0 || property_exists($rval, '@value') || + property_exists($rval, '@list') || + ($count === 1 && property_exists($rval, '@id'))) { + $rval = null; + } + } + + return $rval; + } + + /** + * Performs JSON-LD flattening. + * + * @param array $input the expanded JSON-LD to flatten. + * + * @return array the flattened output. + */ + protected function _flatten($input) { + // produce a map of all subjects and name each bnode + $namer = new UniqueNamer('_:b'); + $graphs = (object)array('@default' => new stdClass()); + $this->_createNodeMap($input, $graphs, '@default', $namer); + + // add all non-default graphs to default graph + $default_graph = $graphs->{'@default'}; + $graph_names = array_keys((array)$graphs); + foreach($graph_names as $graph_name) { + if($graph_name === '@default') { + continue; + } + $node_map = $graphs->{$graph_name}; + if(!property_exists($default_graph, $graph_name)) { + $default_graph->{$graph_name} = (object)array( + '@id' => $graph_name, '@graph' => array()); + } + $subject = $default_graph->{$graph_name}; + if(!property_exists($subject, '@graph')) { + $subject->{'@graph'} = array(); + } + $ids = array_keys((array)$node_map); + sort($ids); + foreach($ids as $id) { + $node = $node_map->{$id}; + // only add full subjects + if(!self::_isSubjectReference($node)) { + $subject->{'@graph'}[] = $node; + } + } + } + + // produce flattened output + $flattened = array(); + $keys = array_keys((array)$default_graph); + sort($keys); + foreach($keys as $key) { + $node = $default_graph->{$key}; + // only add full subjects to top-level + if(!self::_isSubjectReference($node)) { + $flattened[] = $node; + } + } + return $flattened; + } + + /** + * Performs JSON-LD framing. + * + * @param array $input the expanded JSON-LD to frame. + * @param array $frame the expanded JSON-LD frame to use. + * @param assoc $options the framing options. + * + * @return array the framed output. + */ + protected function _frame($input, $frame, $options) { + // create framing state + $state = (object)array( + 'options' => $options, + 'graphs' => (object)array( + '@default' => new stdClass(), + '@merged' => new stdClass()), + 'subjectStack' => array(), + 'link' => new stdClass()); + + // produce a map of all graphs and name each bnode + // FIXME: currently uses subjects from @merged graph only + $namer = new UniqueNamer('_:b'); + $this->_createNodeMap($input, $state->graphs, '@merged', $namer); + $state->subjects = $state->graphs->{'@merged'}; + + // frame the subjects + $framed = new ArrayObject(); + $keys = array_keys((array)$state->subjects); + sort($keys); + $this->_matchFrame($state, $keys, $frame, $framed, null); + return (array)$framed; + } + + /** + * Performs normalization on the given RDF dataset. + * + * @param stdClass $dataset the RDF dataset to normalize. + * @param assoc $options the normalization options. + * + * @return mixed the normalized output. + */ + protected function _normalize($dataset, $options) { + // create quads and map bnodes to their associated quads + $quads = array(); + $bnodes = new stdClass(); + foreach($dataset as $graph_name => $triples) { + if($graph_name === '@default') { + $graph_name = null; + } + foreach($triples as $triple) { + $quad = $triple; + if($graph_name !== null) { + if(strpos($graph_name, '_:') === 0) { + $quad->name = (object)array( + 'type' => 'blank node', 'value' => $graph_name); + } else { + $quad->name = (object)array( + 'type' => 'IRI', 'value' => $graph_name); + } + } + $quads[] = $quad; + + foreach(array('subject', 'object', 'name') as $attr) { + if(property_exists($quad, $attr) && + $quad->{$attr}->type === 'blank node') { + $id = $quad->{$attr}->value; + if(property_exists($bnodes, $id)) { + $bnodes->{$id}->quads[] = $quad; + } else { + $bnodes->{$id} = (object)array('quads' => array($quad)); + } + } + } + } + } + + // mapping complete, start canonical naming + $namer = new UniqueNamer('_:c14n'); + + // continue to hash bnode quads while bnodes are assigned names + $unnamed = null; + $nextUnnamed = array_keys((array)$bnodes); + $duplicates = null; + do { + $unnamed = $nextUnnamed; + $nextUnnamed = array(); + $duplicates = new stdClass(); + $unique = new stdClass(); + foreach($unnamed as $bnode) { + // hash quads for each unnamed bnode + $hash = $this->_hashQuads($bnode, $bnodes, $namer); + + // store hash as unique or a duplicate + if(property_exists($duplicates, $hash)) { + $duplicates->{$hash}[] = $bnode; + $nextUnnamed[] = $bnode; + } else if(property_exists($unique, $hash)) { + $duplicates->{$hash} = array($unique->{$hash}, $bnode); + $nextUnnamed[] = $unique->{$hash}; + $nextUnnamed[] = $bnode; + unset($unique->{$hash}); + } else { + $unique->{$hash} = $bnode; + } + } + + // name unique bnodes in sorted hash order + $hashes = array_keys((array)$unique); + sort($hashes); + foreach($hashes as $hash) { + $namer->getName($unique->{$hash}); + } + } + while(count($unnamed) > count($nextUnnamed)); + + // enumerate duplicate hash groups in sorted order + $hashes = array_keys((array)$duplicates); + sort($hashes); + foreach($hashes as $hash) { + // process group + $group = $duplicates->{$hash}; + $results = array(); + foreach($group as $bnode) { + // skip already-named bnodes + if($namer->isNamed($bnode)) { + continue; + } + + // hash bnode paths + $path_namer = new UniqueNamer('_:b'); + $path_namer->getName($bnode); + $results[] = $this->_hashPaths($bnode, $bnodes, $namer, $path_namer); + } + + // name bnodes in hash order + usort($results, function($a, $b) { + $a = $a->hash; + $b = $b->hash; + return ($a < $b) ? -1 : (($a > $b) ? 1 : 0); + }); + foreach($results as $result) { + // name all bnodes in path namer in key-entry order + foreach($result->pathNamer->order as $bnode) { + $namer->getName($bnode); + } + } + } + + // create normalized array + $normalized = array(); + + /* Note: At this point all bnodes in the set of RDF quads have been + assigned canonical names, which have been stored in the 'namer' object. + Here each quad is updated by assigning each of its bnodes its new name + via the 'namer' object. */ + + // update bnode names in each quad and serialize + foreach($quads as $quad) { + foreach(array('subject', 'object', 'name') as $attr) { + if(property_exists($quad, $attr) && + $quad->{$attr}->type === 'blank node' && + strpos($quad->{$attr}->value, '_:c14n') !== 0) { + $quad->{$attr}->value = $namer->getName($quad->{$attr}->value); + } + } + $normalized[] = $this->toNQuad($quad, property_exists($quad, 'name') ? + $quad->name->value : null); + } + + // sort normalized output + sort($normalized); + + // handle output format + if(isset($options['format']) && $options['format']) { + if($options['format'] === 'application/nquads') { + return implode($normalized); + } + throw new JsonLdException( + 'Unknown output format.', + 'jsonld.UnknownFormat', null, array('format' => $options['format'])); + } + + // return RDF dataset + return $this->parseNQuads(implode($normalized)); + } + + /** + * Converts an RDF dataset to JSON-LD. + * + * @param stdClass $dataset the RDF dataset. + * @param assoc $options the RDF serialization options. + * + * @return array the JSON-LD output. + */ + protected function _fromRDF($dataset, $options) { + $default_graph = new stdClass(); + $graph_map = (object)array('@default' => $default_graph); + $referenced_once = (object)array(); + + foreach($dataset as $name => $graph) { + if(!property_exists($graph_map, $name)) { + $graph_map->{$name} = new stdClass(); + } + if($name !== '@default' && !property_exists($default_graph, $name)) { + $default_graph->{$name} = (object)array('@id' => $name); + } + $node_map = $graph_map->{$name}; + foreach($graph as $triple) { + // get subject, predicate, object + $s = $triple->subject->value; + $p = $triple->predicate->value; + $o = $triple->object; + + if(!property_exists($node_map, $s)) { + $node_map->{$s} = (object)array('@id' => $s); + } + $node = $node_map->{$s}; + + $object_is_id = ($o->type === 'IRI' || $o->type === 'blank node'); + if($object_is_id && !property_exists($node_map, $o->value)) { + $node_map->{$o->value} = (object)array('@id' => $o->value); + } + + if($p === self::RDF_TYPE && !$options['useRdfType'] && $object_is_id) { + self::addValue( + $node, '@type', $o->value, array('propertyIsArray' => true)); + continue; + } + + $value = self::_RDFToObject($o, $options['useNativeTypes']); + self::addValue($node, $p, $value, array('propertyIsArray' => true)); + + // object may be an RDF list/partial list node but we can't know + // easily until all triples are read + if($object_is_id) { + if($o->value === self::RDF_NIL) { + $object = $node_map->{$o->value}; + if(!property_exists($object, 'usages')) { + $object->usages = array(); + } + $object->usages[] = (object)array( + 'node' => $node, + 'property' => $p, + 'value' => $value); + } else if(property_exists($referenced_once, $o->value)) { + // object referenced more than once + $referenced_once->{$o->value} = false; + } else { + // track single reference + $referenced_once->{$o->value} = (object)array( + 'node' => $node, + 'property' => $p, + 'value' => $value); + } + } + } + } + + // convert linked lists to @list arrays + foreach($graph_map as $name => $graph_object) { + // no @lists to be converted, continue + if(!property_exists($graph_object, self::RDF_NIL)) { + continue; + } + + // iterate backwards through each RDF list + $nil = $graph_object->{self::RDF_NIL}; + foreach($nil->usages as $usage) { + $node = $usage->node; + $property = $usage->property; + $head = $usage->value; + $list = array(); + $list_nodes = array(); + + // ensure node is a well-formed list node; it must: + // 1. Be referenced only once. + // 2. Have an array for rdf:first that has 1 item. + // 3. Have an array for rdf:rest that has 1 item. + // 4. Have no keys other than: @id, rdf:first, rdf:rest, and, + // optionally, @type where the value is rdf:List. + $node_key_count = count(array_keys((array)$node)); + while($property === self::RDF_REST && + property_exists($referenced_once, $node->{'@id'}) && + is_object($referenced_once->{$node->{'@id'}}) && + property_exists($node, self::RDF_FIRST) && + property_exists($node, self::RDF_REST) && + is_array($node->{self::RDF_FIRST}) && + is_array($node->{self::RDF_REST}) && + count($node->{self::RDF_FIRST}) === 1 && + count($node->{self::RDF_REST}) === 1 && + ($node_key_count === 3 || ($node_key_count === 4 && + property_exists($node, '@type') && is_array($node->{'@type'}) && + count($node->{'@type'}) === 1 && + $node->{'@type'}[0] === self::RDF_LIST))) { + $list[] = $node->{self::RDF_FIRST}[0]; + $list_nodes[] = $node->{'@id'}; + + // get next node, moving backwards through list + $usage = $referenced_once->{$node->{'@id'}}; + $node = $usage->node; + $property = $usage->property; + $head = $usage->value; + $node_key_count = count(array_keys((array)$node)); + + // if node is not a blank node, then list head found + if(strpos($node->{'@id'}, '_:') !== 0) { + break; + } + } + + // list is nested in another list + if($property === self::RDF_FIRST) { + // empty list + if($node->{'@id'} === self::RDF_NIL) { + // can't convert rdf:nil to a @list object because it would + // result in a list of lists which isn't supported + continue; + } + + // preserve list head + $head = $graph_object->{$head->{'@id'}}->{self::RDF_REST}[0]; + array_pop($list); + array_pop($list_nodes); + } + + // transform list into @list object + unset($head->{'@id'}); + $head->{'@list'} = array_reverse($list); + foreach($list_nodes as $list_node) { + unset($graph_object->{$list_node}); + } + } + + unset($nil->usages); + } + + $result = array(); + $subjects = array_keys((array)$default_graph); + sort($subjects); + foreach($subjects as $subject) { + $node = $default_graph->{$subject}; + if(property_exists($graph_map, $subject)) { + $node->{'@graph'} = array(); + $graph_object = $graph_map->{$subject}; + $subjects_ = array_keys((array)$graph_object); + sort($subjects_); + foreach($subjects_ as $subject_) { + $node_ = $graph_object->{$subject_}; + // only add full subjects to top-level + if(!self::_isSubjectReference($node_)) { + $node->{'@graph'}[] = $node_; + } + } + } + // only add full subjects to top-level + if(!self::_isSubjectReference($node)) { + $result[] = $node; + } + } + + return $result; + } + + /** + * Processes a local context and returns a new active context. + * + * @param stdClass $active_ctx the current active context. + * @param mixed $local_ctx the local context to process. + * @param assoc $options the context processing options. + * + * @return stdClass the new active context. + */ + protected function _processContext($active_ctx, $local_ctx, $options) { + global $jsonld_cache; + + // normalize local context to an array + if(is_object($local_ctx) && property_exists($local_ctx, '@context') && + is_array($local_ctx->{'@context'})) { + $local_ctx = $local_ctx->{'@context'}; + } + $ctxs = self::arrayify($local_ctx); + + // no contexts in array, clone existing context + if(count($ctxs) === 0) { + return self::_cloneActiveContext($active_ctx); + } + + // process each context in order, update active context + // on each iteration to ensure proper caching + $rval = $active_ctx; + foreach($ctxs as $ctx) { + // reset to initial context + if($ctx === null) { + $rval = $active_ctx = $this->_getInitialContext($options); + continue; + } + + // dereference @context key if present + if(is_object($ctx) && property_exists($ctx, '@context')) { + $ctx = $ctx->{'@context'}; + } + + // context must be an object by now, all URLs retrieved before this call + if(!is_object($ctx)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context must be an object.', + 'jsonld.SyntaxError', 'invalid local context', + array('context' => $ctx)); + } + + // get context from cache if available + if(property_exists($jsonld_cache, 'activeCtx')) { + $cached = $jsonld_cache->activeCtx->get($active_ctx, $ctx); + if($cached) { + $rval = $active_ctx = $cached; + $must_clone = true; + continue; + } + } + + // update active context and clone new one before updating + $active_ctx = $rval; + $rval = self::_cloneActiveContext($rval); + + // define context mappings for keys in local context + $defined = new stdClass(); + + // handle @base + if(property_exists($ctx, '@base')) { + $base = $ctx->{'@base'}; + if($base === null) { + $base = null; + } else if(!is_string($base)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; the value of "@base" in a ' . + '@context must be a string or null.', + 'jsonld.SyntaxError', 'invalid base IRI', array('context' => $ctx)); + } else if($base !== '' && !self::_isAbsoluteIri($base)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; the value of "@base" in a ' . + '@context must be an absolute IRI or the empty string.', + 'jsonld.SyntaxError', 'invalid base IRI', array('context' => $ctx)); + } + if($base !== null) { + $base = jsonld_parse_url($base); + } + $rval->{'@base'} = $base; + $defined->{'@base'} = true; + } + + // handle @vocab + if(property_exists($ctx, '@vocab')) { + $value = $ctx->{'@vocab'}; + if($value === null) { + unset($rval->{'@vocab'}); + } else if(!is_string($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; the value of "@vocab" in a ' . + '@context must be a string or null.', + 'jsonld.SyntaxError', 'invalid vocab mapping', + array('context' => $ctx)); + } else if(!self::_isAbsoluteIri($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; the value of "@vocab" in a ' . + '@context must be an absolute IRI.', + 'jsonld.SyntaxError', 'invalid vocab mapping', + array('context' => $ctx)); + } else { + $rval->{'@vocab'} = $value; + } + $defined->{'@vocab'} = true; + } + + // handle @language + if(property_exists($ctx, '@language')) { + $value = $ctx->{'@language'}; + if($value === null) { + unset($rval->{'@language'}); + } else if(!is_string($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; the value of "@language" in a ' . + '@context must be a string or null.', + 'jsonld.SyntaxError', 'invalid default language', + array('context' => $ctx)); + } else { + $rval->{'@language'} = strtolower($value); + } + $defined->{'@language'} = true; + } + + // process all other keys + foreach($ctx as $k => $v) { + $this->_createTermDefinition($rval, $ctx, $k, $defined); + } + + // cache result + if(property_exists($jsonld_cache, 'activeCtx')) { + $jsonld_cache->activeCtx->set($active_ctx, $ctx, $rval); + } + } + + return $rval; + } + + /** + * Expands a language map. + * + * @param stdClass $language_map the language map to expand. + * + * @return array the expanded language map. + */ + protected function _expandLanguageMap($language_map) { + $rval = array(); + $keys = array_keys((array)$language_map); + sort($keys); + foreach($keys as $key) { + $values = $language_map->{$key}; + $values = self::arrayify($values); + foreach($values as $item) { + if($item === null) { + continue; + } + if(!is_string($item)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; language map values must be strings.', + 'jsonld.SyntaxError', 'invalid language map value', + array('languageMap', $language_map)); + } + $rval[] = (object)array( + '@value' => $item, + '@language' => strtolower($key)); + } + } + return $rval; + } + + /** + * Labels the blank nodes in the given value using the given UniqueNamer. + * + * @param UniqueNamer $namer the UniqueNamer to use. + * @param mixed $element the element with blank nodes to rename. + * + * @return mixed the element. + */ + public function _labelBlankNodes($namer, $element) { + if(is_array($element)) { + $length = count($element); + for($i = 0; $i < $length; ++$i) { + $element[$i] = $this->_labelBlankNodes($namer, $element[$i]); + } + } else if(self::_isList($element)) { + $element->{'@list'} = $this->_labelBlankNodes( + $namer, $element->{'@list'}); + } else if(is_object($element)) { + // rename blank node + if(self::_isBlankNode($element)) { + $name = null; + if(property_exists($element, '@id')) { + $name = $element->{'@id'}; + } + $element->{'@id'} = $namer->getName($name); + } + + // recursively apply to all keys + $keys = array_keys((array)$element); + sort($keys); + foreach($keys as $key) { + if($key !== '@id') { + $element->{$key} = $this->_labelBlankNodes($namer, $element->{$key}); + } + } + } + + return $element; + } + + /** + * Expands the given value by using the coercion and keyword rules in the + * given context. + * + * @param stdClass $active_ctx the active context to use. + * @param string $active_property the property the value is associated with. + * @param mixed $value the value to expand. + * + * @return mixed the expanded value. + */ + protected function _expandValue($active_ctx, $active_property, $value) { + // nothing to expand + if($value === null) { + return null; + } + + // special-case expand @id and @type (skips '@id' expansion) + $expanded_property = $this->_expandIri( + $active_ctx, $active_property, array('vocab' => true)); + if($expanded_property === '@id') { + return $this->_expandIri($active_ctx, $value, array('base' => true)); + } else if($expanded_property === '@type') { + return $this->_expandIri( + $active_ctx, $value, array('vocab' => true, 'base' => true)); + } + + // get type definition from context + $type = self::getContextValue($active_ctx, $active_property, '@type'); + + // do @id expansion (automatic for @graph) + if($type === '@id' || ($expanded_property === '@graph' && + is_string($value))) { + return (object)array('@id' => $this->_expandIri( + $active_ctx, $value, array('base' => true))); + } + // do @id expansion w/vocab + if($type === '@vocab') { + return (object)array('@id' => $this->_expandIri( + $active_ctx, $value, array('vocab' => true, 'base' => true))); + } + + // do not expand keyword values + if(self::_isKeyword($expanded_property)) { + return $value; + } + + $rval = new stdClass(); + + // other type + if($type !== null) { + $rval->{'@type'} = $type; + } else if(is_string($value)) { + // check for language tagging for strings + $language = self::getContextValue( + $active_ctx, $active_property, '@language'); + if($language !== null) { + $rval->{'@language'} = $language; + } + } + $rval->{'@value'} = $value; + + return $rval; + } + + /** + * Creates an array of RDF triples for the given graph. + * + * @param stdClass $graph the graph to create RDF triples for. + * @param UniqueNamer $namer for assigning bnode names. + * @param assoc $options the RDF serialization options. + * + * @return array the array of RDF triples for the given graph. + */ + protected function _graphToRDF($graph, $namer, $options) { + $rval = array(); + + $ids = array_keys((array)$graph); + sort($ids); + foreach($ids as $id) { + $node = $graph->{$id}; + if($id === '"') { + $id = ''; + } + $properties = array_keys((array)$node); + sort($properties); + foreach($properties as $property) { + $items = $node->{$property}; + if($property === '@type') { + $property = self::RDF_TYPE; + } else if(self::_isKeyword($property)) { + continue; + } + + foreach($items as $item) { + // skip relative IRI subjects and predicates + if(!(self::_isAbsoluteIri($id) && self::_isAbsoluteIri($property))) { + continue; + } + + // RDF subject + $subject = new stdClass(); + $subject->type = (strpos($id, '_:') === 0) ? 'blank node' : 'IRI'; + $subject->value = $id; + + // RDF predicate + $predicate = new stdClass(); + $predicate->type = (strpos($property, '_:') === 0 ? + 'blank node' : 'IRI'); + $predicate->value = $property; + + // skip bnode predicates unless producing generalized RDF + if($predicate->type === 'blank node' && + !$options['produceGeneralizedRdf']) { + continue; + } + + if(self::_isList($item)) { + // convert @list to triples + $this->_listToRDF( + $item->{'@list'}, $namer, $subject, $predicate, $rval); + } else { + // convert value or node object to triple + $object = $this->_objectToRDF($item); + // skip null objects (they are relative IRIs) + if($object) { + $rval[] = (object)array( + 'subject' => $subject, + 'predicate' => $predicate, + 'object' => $object); + } + } + } + } + } + + return $rval; + } + + /** + * Converts a @list value into linked list of blank node RDF triples + * (an RDF collection). + * + * @param array $list the @list value. + * @param UniqueNamer $namer for assigning blank node names. + * @param stdClass $subject the subject for the head of the list. + * @param stdClass $predicate the predicate for the head of the list. + * @param &array $triples the array of triples to append to. + */ + protected function _listToRDF( + $list, $namer, $subject, $predicate, &$triples) { + $first = (object)array('type' => 'IRI', 'value' => self::RDF_FIRST); + $rest = (object)array('type' => 'IRI', 'value' => self::RDF_REST); + $nil = (object)array('type' => 'IRI', 'value' => self::RDF_NIL); + + foreach($list as $item) { + $blank_node = (object)array( + 'type' => 'blank node', 'value' => $namer->getName()); + $triples[] = (object)array( + 'subject' => $subject, + 'predicate' => $predicate, + 'object' => $blank_node); + + $subject = $blank_node; + $predicate = $first; + $object = $this->_objectToRDF($item); + // skip null objects (they are relative IRIs) + if($object) { + $triples[] = (object)array( + 'subject' => $subject, + 'predicate' => $predicate, + 'object' => $object); + } + + $predicate = $rest; + } + + $triples[] = (object)array( + 'subject' => $subject, 'predicate' => $predicate, 'object' => $nil); + } + + /** + * Converts a JSON-LD value object to an RDF literal or a JSON-LD string or + * node object to an RDF resource. + * + * @param mixed $item the JSON-LD value or node object. + * + * @return stdClass the RDF literal or RDF resource. + */ + protected function _objectToRDF($item) { + $object = new stdClass(); + + if(self::_isValue($item)) { + $object->type = 'literal'; + $value = $item->{'@value'}; + $datatype = property_exists($item, '@type') ? $item->{'@type'} : null; + + // convert to XSD datatypes as appropriate + if(is_bool($value)) { + $object->value = ($value ? 'true' : 'false'); + $object->datatype = $datatype ? $datatype : self::XSD_BOOLEAN; + } else if(is_double($value) || $datatype == self::XSD_DOUBLE) { + // canonical double representation + $object->value = preg_replace( + '/(\d)0*E\+?/', '$1E', sprintf('%1.15E', $value)); + $object->datatype = $datatype ? $datatype : self::XSD_DOUBLE; + } else if(is_integer($value)) { + $object->value = strval($value); + $object->datatype = $datatype ? $datatype : self::XSD_INTEGER; + } else if(property_exists($item, '@language')) { + $object->value = $value; + $object->datatype = $datatype ? $datatype : self::RDF_LANGSTRING; + $object->language = $item->{'@language'}; + } else { + $object->value = $value; + $object->datatype = $datatype ? $datatype : self::XSD_STRING; + } + } else { + // convert string/node object to RDF + $id = is_object($item) ? $item->{'@id'} : $item; + $object->type = (strpos($id, '_:') === 0) ? 'blank node' : 'IRI'; + $object->value = $id; + } + + // skip relative IRIs + if($object->type === 'IRI' && !self::_isAbsoluteIri($object->value)) { + return null; + } + + return $object; + } + + /** + * Converts an RDF triple object to a JSON-LD object. + * + * @param stdClass $o the RDF triple object to convert. + * @param bool $use_native_types true to output native types, false not to. + * + * @return stdClass the JSON-LD object. + */ + protected function _RDFToObject($o, $use_native_types) { + // convert IRI/blank node object to JSON-LD + if($o->type === 'IRI' || $o->type === 'blank node') { + return (object)array('@id' => $o->value); + } + + // convert literal object to JSON-LD + $rval = (object)array('@value' => $o->value); + + if(property_exists($o, 'language')) { + // add language + $rval->{'@language'} = $o->language; + } else { + // add datatype + $type = $o->datatype; + // use native types for certain xsd types + if($use_native_types) { + if($type === self::XSD_BOOLEAN) { + if($rval->{'@value'} === 'true') { + $rval->{'@value'} = true; + } else if($rval->{'@value'} === 'false') { + $rval->{'@value'} = false; + } + } else if(is_numeric($rval->{'@value'})) { + if($type === self::XSD_INTEGER) { + $i = intval($rval->{'@value'}); + if(strval($i) === $rval->{'@value'}) { + $rval->{'@value'} = $i; + } + } else if($type === self::XSD_DOUBLE) { + $rval->{'@value'} = doubleval($rval->{'@value'}); + } + } + // do not add native type + if(!in_array($type, array( + self::XSD_BOOLEAN, self::XSD_INTEGER, self::XSD_DOUBLE, + self::XSD_STRING))) { + $rval->{'@type'} = $type; + } + } else if($type !== self::XSD_STRING) { + $rval->{'@type'} = $type; + } + } + + return $rval; + } + + /** + * Recursively flattens the subjects in the given JSON-LD expanded input + * into a node map. + * + * @param mixed $input the JSON-LD expanded input. + * @param stdClass $graphs a map of graph name to subject map. + * @param string $graph the name of the current graph. + * @param UniqueNamer $namer the blank node namer. + * @param mixed $name the name assigned to the current input if it is a bnode. + * @param mixed $list the list to append to, null for none. + */ + protected function _createNodeMap( + $input, $graphs, $graph, $namer, $name=null, $list=null) { + // recurse through array + if(is_array($input)) { + foreach($input as $e) { + $this->_createNodeMap($e, $graphs, $graph, $namer, null, $list); + } + return; + } + + // add non-object to list + if(!is_object($input)) { + if($list !== null) { + $list[] = $input; + } + return; + } + + // add values to list + if(self::_isValue($input)) { + if(property_exists($input, '@type')) { + $type = $input->{'@type'}; + // rename @type blank node + if(strpos($type, '_:') === 0) { + $type = $input->{'@type'} = $namer->getName($type); + } + } + if($list !== null) { + $list[] = $input; + } + return; + } + + // Note: At this point, input must be a subject. + + // spec requires @type to be named first, so assign names early + if(property_exists($input, '@type')) { + foreach($input->{'@type'} as $type) { + if(strpos($type, '_:') === 0) { + $namer->getName($type); + } + } + } + + // get name for subject + if($name === null) { + if(property_exists($input, '@id')) { + $name = $input->{'@id'}; + } + if(self::_isBlankNode($input)) { + $name = $namer->getName($name); + } + } + + // add subject reference to list + if($list !== null) { + $list[] = (object)array('@id' => $name); + } + + // create new subject or merge into existing one + if(!property_exists($graphs, $graph)) { + $graphs->{$graph} = new stdClass(); + } + $subjects = $graphs->{$graph}; + if(!property_exists($subjects, $name)) { + if($name === '') { + $subjects->{'"'} = new stdClass(); + } else { + $subjects->{$name} = new stdClass(); + } + } + if($name === '') { + $subject = $subjects->{'"'}; + } else { + $subject = $subjects->{$name}; + } + $subject->{'@id'} = $name; + $properties = array_keys((array)$input); + sort($properties); + foreach($properties as $property) { + // skip @id + if($property === '@id') { + continue; + } + + // handle reverse properties + if($property === '@reverse') { + $referenced_node = (object)array('@id' => $name); + $reverse_map = $input->{'@reverse'}; + foreach($reverse_map as $reverse_property => $items) { + foreach($items as $item) { + $item_name = null; + if(property_exists($item, '@id')) { + $item_name = $item->{'@id'}; + } + if(self::_isBlankNode($item)) { + $item_name = $namer->getName($item_name); + } + $this->_createNodeMap($item, $graphs, $graph, $namer, $item_name); + if($item_name === '') { + $item_name = '"'; + } + self::addValue( + $subjects->{$item_name}, $reverse_property, $referenced_node, + array('propertyIsArray' => true, 'allowDuplicate' => false)); + } + } + continue; + } + + // recurse into graph + if($property === '@graph') { + // add graph subjects map entry + if(!property_exists($graphs, $name)) { + // FIXME: temporary hack to avoid empty property bug + if(!$name) { + $name = '"'; + } + $graphs->{$name} = new stdClass(); + } + $g = ($graph === '@merged') ? $graph : $name; + $this->_createNodeMap( + $input->{$property}, $graphs, $g, $namer, null, null); + continue; + } + + // copy non-@type keywords + if($property !== '@type' && self::_isKeyword($property)) { + if($property === '@index' && property_exists($subject, '@index') && + ($input->{'@index'} !== $subject->{'@index'} || + $input->{'@index'}->{'@id'} !== $subject->{'@index'}->{'@id'})) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; conflicting @index property detected.', + 'jsonld.SyntaxError', 'conflicting indexes', + array('subject' => $subject)); + } + $subject->{$property} = $input->{$property}; + continue; + } + + // iterate over objects + $objects = $input->{$property}; + + // if property is a bnode, assign it a new id + if(strpos($property, '_:') === 0) { + $property = $namer->getName($property); + } + + // ensure property is added for empty arrays + if(count($objects) === 0) { + self::addValue( + $subject, $property, array(), array('propertyIsArray' => true)); + continue; + } + foreach($objects as $o) { + if($property === '@type') { + // rename @type blank nodes + $o = (strpos($o, '_:') === 0) ? $namer->getName($o) : $o; + } + + // handle embedded subject or subject reference + if(self::_isSubject($o) || self::_isSubjectReference($o)) { + // rename blank node @id + $id = property_exists($o, '@id') ? $o->{'@id'} : null; + if(self::_isBlankNode($o)) { + $id = $namer->getName($id); + } + + // add reference and recurse + self::addValue( + $subject, $property, (object)array('@id' => $id), + array('propertyIsArray' => true, 'allowDuplicate' => false)); + $this->_createNodeMap($o, $graphs, $graph, $namer, $id, null); + } else if(self::_isList($o)) { + // handle @list + $_list = new ArrayObject(); + $this->_createNodeMap( + $o->{'@list'}, $graphs, $graph, $namer, $name, $_list); + $o = (object)array('@list' => (array)$_list); + self::addValue( + $subject, $property, $o, + array('propertyIsArray' => true, 'allowDuplicate' => false)); + } else { + // handle @value + $this->_createNodeMap($o, $graphs, $graph, $namer, $name, null); + self::addValue( + $subject, $property, $o, + array('propertyIsArray' => true, 'allowDuplicate' => false)); + } + } + } + } + + /** + * Frames subjects according to the given frame. + * + * @param stdClass $state the current framing state. + * @param array $subjects the subjects to filter. + * @param array $frame the frame. + * @param mixed $parent the parent subject or top-level array. + * @param mixed $property the parent property, initialized to null. + */ + protected function _matchFrame( + $state, $subjects, $frame, $parent, $property) { + // validate the frame + $this->_validateFrame($frame); + $frame = $frame[0]; + + // get flags for current frame + $options = $state->options; + $flags = array( + 'embed' => $this->_getFrameFlag($frame, $options, 'embed'), + 'explicit' => $this->_getFrameFlag($frame, $options, 'explicit'), + 'requireAll' => $this->_getFrameFlag($frame, $options, 'requireAll')); + + // filter out subjects that match the frame + $matches = $this->_filterSubjects($state, $subjects, $frame, $flags); + + // add matches to output + foreach($matches as $id => $subject) { + if($flags['embed'] === '@link' && property_exists($state->link, $id)) { + // TODO: may want to also match an existing linked subject against + // the current frame ... so different frames could produce different + // subjects that are only shared in-memory when the frames are the same + + // add existing linked subject + $this->_addFrameOutput($parent, $property, $state->link->{$id}); + continue; + } + + /* Note: In order to treat each top-level match as a compartmentalized + result, clear the unique embedded subjects map when the property is null, + which only occurs at the top-level. */ + if($property === null) { + $state->uniqueEmbeds = new stdClass(); + } + + // start output for subject + $output = new stdClass(); + $output->{'@id'} = $id; + $state->link->{$id} = $output; + + // if embed is @never or if a circular reference would be created by an + // embed, the subject cannot be embedded, just add the reference; + // note that a circular reference won't occur when the embed flag is + // `@link` as the above check will short-circuit before reaching this point + if($flags['embed'] === '@never' || + $this->_createsCircularReference($subject, $state->subjectStack)) { + $this->_addFrameOutput($parent, $property, $output); + continue; + } + + // if only the last match should be embedded + if($flags['embed'] === '@last') { + // remove any existing embed + if(property_exists($state->uniqueEmbeds, $id)) { + $this->_removeEmbed($state, $id); + } + $state->uniqueEmbeds->{$id} = array( + 'parent' => $parent, 'property' => $property); + } + + // push matching subject onto stack to enable circular embed checks + $state->subjectStack[] = $subject; + + // iterate over subject properties + $props = array_keys((array)$subject); + sort($props); + foreach($props as $prop) { + // copy keywords to output + if(self::_isKeyword($prop)) { + $output->{$prop} = self::copy($subject->{$prop}); + continue; + } + + // explicit is on and property isn't in the frame, skip processing + if($flags['explicit'] && !property_exists($frame, $prop)) { + continue; + } + + // add objects + $objects = $subject->{$prop}; + foreach($objects as $o) { + // recurse into list + if(self::_isList($o)) { + // add empty list + $list = (object)array('@list' => array()); + $this->_addFrameOutput($output, $prop, $list); + + // add list objects + $src = $o->{'@list'}; + foreach($src as $o) { + if(self::_isSubjectReference($o)) { + // recurse into subject reference + $subframe = (property_exists($frame, $prop) ? + $frame->{$prop}[0]->{'@list'} : + $this->_createImplicitFrame($flags)); + $this->_matchFrame( + $state, array($o->{'@id'}), $subframe, $list, '@list'); + } else { + // include other values automatically + $this->_addFrameOutput($list, '@list', self::copy($o)); + } + } + continue; + } + + if(self::_isSubjectReference($o)) { + // recurse into subject reference + $subframe = (property_exists($frame, $prop) ? + $frame->{$prop} : $this->_createImplicitFrame($flags)); + $this->_matchFrame( + $state, array($o->{'@id'}), $subframe, $output, $prop); + } else { + // include other values automatically + $this->_addFrameOutput($output, $prop, self::copy($o)); + } + } + } + + // handle defaults + $props = array_keys((array)$frame); + sort($props); + foreach($props as $prop) { + // skip keywords + if(self::_isKeyword($prop)) { + continue; + } + + // if omit default is off, then include default values for properties + // that appear in the next frame but are not in the matching subject + $next = $frame->{$prop}[0]; + $omit_default_on = $this->_getFrameFlag( + $next, $options, 'omitDefault'); + if(!$omit_default_on && !property_exists($output, $prop)) { + $preserve = '@null'; + if(property_exists($next, '@default')) { + $preserve = self::copy($next->{'@default'}); + } + $preserve = self::arrayify($preserve); + $output->{$prop} = array((object)array('@preserve' => $preserve)); + } + } + + // add output to parent + $this->_addFrameOutput($parent, $property, $output); + + // pop matching subject from circular ref-checking stack + array_pop($state->subjectStack); + } + } + + /** + * Creates an implicit frame when recursing through subject matches. If + * a frame doesn't have an explicit frame for a particular property, then + * a wildcard child frame will be created that uses the same flags that the + * parent frame used. + * + * @param assoc flags the current framing flags. + * + * @return array the implicit frame. + */ + function _createImplicitFrame($flags) { + $frame = new stdClass(); + foreach($flags as $key => $value) { + $frame->{'@' . $key} = array($flags[$key]); + } + return array($frame); + } + + /** + * Checks the current subject stack to see if embedding the given subject + * would cause a circular reference. + * + * @param stdClass subject_to_embed the subject to embed. + * @param assoc subject_stack the current stack of subjects. + * + * @return bool true if a circular reference would be created, false if not. + */ + function _createsCircularReference($subject_to_embed, $subject_stack) { + for($i = count($subject_stack) - 1; $i >= 0; --$i) { + if($subject_stack[$i]->{'@id'} === $subject_to_embed->{'@id'}) { + return true; + } + } + return false; + } + + /** + * Gets the frame flag value for the given flag name. + * + * @param stdClass $frame the frame. + * @param stdClass $options the framing options. + * @param string $name the flag name. + * + * @return mixed $the flag value. + */ + protected function _getFrameFlag($frame, $options, $name) { + $flag = "@$name"; + $rval = (property_exists($frame, $flag) ? + $frame->{$flag}[0] : $options[$name]); + if($name === 'embed') { + // default is "@last" + // backwards-compatibility support for "embed" maps: + // true => "@last" + // false => "@never" + if($rval === true) { + $rval = '@last'; + } else if($rval === false) { + $rval = '@never'; + } else if($rval !== '@always' && $rval !== '@never' && + $rval !== '@link') { + $rval = '@last'; + } + } + return $rval; + } + + /** + * Validates a JSON-LD frame, throwing an exception if the frame is invalid. + * + * @param array $frame the frame to validate. + */ + protected function _validateFrame($frame) { + if(!is_array($frame) || count($frame) !== 1 || !is_object($frame[0])) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; a JSON-LD frame must be a single object.', + 'jsonld.SyntaxError', null, array('frame' => $frame)); + } + } + + /** + * Returns a map of all of the subjects that match a parsed frame. + * + * @param stdClass $state the current framing state. + * @param array $subjects the set of subjects to filter. + * @param stdClass $frame the parsed frame. + * @param assoc $flags the frame flags. + * + * @return stdClass all of the matched subjects. + */ + protected function _filterSubjects($state, $subjects, $frame, $flags) { + $rval = new stdClass(); + sort($subjects); + foreach($subjects as $id) { + $subject = $state->subjects->{$id}; + if($this->_filterSubject($subject, $frame, $flags)) { + $rval->{$id} = $subject; + } + } + return $rval; + } + + /** + * Returns true if the given subject matches the given frame. + * + * @param stdClass $subject the subject to check. + * @param stdClass $frame the frame to check. + * @param assoc $flags the frame flags. + * + * @return bool true if the subject matches, false if not. + */ + protected function _filterSubject($subject, $frame, $flags) { + // check @type (object value means 'any' type, fall through to ducktyping) + if(property_exists($frame, '@type') && + !(count($frame->{'@type'}) === 1 && is_object($frame->{'@type'}[0]))) { + $types = $frame->{'@type'}; + foreach($types as $type) { + // any matching @type is a match + if(self::hasValue($subject, '@type', $type)) { + return true; + } + } + return false; + } + + // check ducktype + $wildcard = true; + $matches_some = false; + foreach($frame as $k => $v) { + if(self::_isKeyword($k)) { + // skip non-@id and non-@type + if($k !== '@id' && $k !== '@type') { + continue; + } + $wildcard = false; + + // check @id for a specific @id value + if($k === '@id' && is_string($v)) { + if(!property_exists($subject, $k) || $subject->{$k} !== $v) { + return false; + } + $matches_some = true; + continue; + } + } + + $wildcard = false; + + if(property_exists($subject, $k)) { + // $v === [] means do not match if property is present + if(is_array($v) && count($v) === 0) { + return false; + } + $matches_some = true; + continue; + } + + // all properties must match to be a duck unless a @default is specified + $has_default = (is_array($v) && count($v) === 1 && is_object($v[0]) && + property_exists($v[0], '@default')); + if($flags['requireAll'] && !$has_default) { + return false; + } + } + + // return true if wildcard or subject matches some properties + return $wildcard || $matches_some; + } + + /** + * Removes an existing embed. + * + * @param stdClass $state the current framing state. + * @param string $id the @id of the embed to remove. + */ + protected function _removeEmbed($state, $id) { + // get existing embed + $embeds = $state->uniqueEmbeds; + $embed = $embeds->{$id}; + $property = $embed['property']; + + // create reference to replace embed + $subject = (object)array('@id' => $id); + + // remove existing embed + if(is_array($embed->parent)) { + // replace subject with reference + foreach($embed->parent as $i => $parent) { + if(self::compareValues($parent, $subject)) { + $embed->parent[$i] = $subject; + break; + } + } + } else { + // replace subject with reference + $use_array = is_array($embed->parent->{$property}); + self::removeValue($embed->parent, $property, $subject, + array('propertyIsArray' => $use_array)); + self::addValue($embed->parent, $property, $subject, + array('propertyIsArray' => $use_array)); + } + + // recursively remove dependent dangling embeds + $removeDependents = function($id) { + // get embed keys as a separate array to enable deleting keys in map + $ids = array_keys((array)$embeds); + foreach($ids as $next) { + if(property_exists($embeds, $next) && + is_object($embeds->{$next}->parent) && + $embeds->{$next}->parent->{'@id'} === $id) { + unset($embeds->{$next}); + $removeDependents($next); + } + } + }; + $removeDependents($id); + } + + /** + * Adds framing output to the given parent. + * + * @param mixed $parent the parent to add to. + * @param string $property the parent property. + * @param mixed $output the output to add. + */ + protected function _addFrameOutput($parent, $property, $output) { + if(is_object($parent) && !($parent instanceof ArrayObject)) { + self::addValue( + $parent, $property, $output, array('propertyIsArray' => true)); + } else { + $parent[] = $output; + } + } + + /** + * Removes the @preserve keywords as the last step of the framing algorithm. + * + * @param stdClass $ctx the active context used to compact the input. + * @param mixed $input the framed, compacted output. + * @param assoc $options the compaction options used. + * + * @return mixed the resulting output. + */ + protected function _removePreserve($ctx, $input, $options) { + // recurse through arrays + if(is_array($input)) { + $output = array(); + foreach($input as $e) { + $result = $this->_removePreserve($ctx, $e, $options); + // drop nulls from arrays + if($result !== null) { + $output[] = $result; + } + } + $input = $output; + } else if(is_object($input)) { + // remove @preserve + if(property_exists($input, '@preserve')) { + if($input->{'@preserve'} === '@null') { + return null; + } + return $input->{'@preserve'}; + } + + // skip @values + if(self::_isValue($input)) { + return $input; + } + + // recurse through @lists + if(self::_isList($input)) { + $input->{'@list'} = $this->_removePreserve( + $ctx, $input->{'@list'}, $options); + return $input; + } + + // handle in-memory linked nodes + $id_alias = $this->_compactIri($ctx, '@id'); + if(property_exists($input, $id_alias)) { + $id = $input->{$id_alias}; + if(isset($options['link'][$id])) { + $idx = array_search($input, $options['link'][$id]); + if($idx === false) { + // prevent circular visitation + $options['link'][$id][] = $input; + } else { + // already visited + return $options['link'][$id][$idx]; + } + } else { + // prevent circular visitation + $options['link'][$id] = array($input); + } + } + + // recurse through properties + foreach($input as $prop => $v) { + $result = $this->_removePreserve($ctx, $v, $options); + $container = self::getContextValue($ctx, $prop, '@container'); + if($options['compactArrays'] && + is_array($result) && count($result) === 1 && + $container !== '@set' && $container !== '@list') { + $result = $result[0]; + } + $input->{$prop} = $result; + } + } + return $input; + } + + /** + * Compares two RDF triples for equality. + * + * @param stdClass $t1 the first triple. + * @param stdClass $t2 the second triple. + * + * @return true if the triples are the same, false if not. + */ + protected static function _compareRDFTriples($t1, $t2) { + foreach(array('subject', 'predicate', 'object') as $attr) { + if($t1->{$attr}->type !== $t2->{$attr}->type || + $t1->{$attr}->value !== $t2->{$attr}->value) { + return false; + } + } + if(property_exists($t1->object, 'language') !== + property_exists($t1->object, 'language')) { + return false; + } + if(property_exists($t1->object, 'language') && + $t1->object->language !== $t2->object->language) { + return false; + } + if(property_exists($t1->object, 'datatype') && + $t1->object->datatype !== $t2->object->datatype) { + return false; + } + return true; + } + + /** + * Hashes all of the quads about a blank node. + * + * @param string $id the ID of the bnode to hash quads for. + * @param stdClass $bnodes the mapping of bnodes to quads. + * @param UniqueNamer $namer the canonical bnode namer. + * + * @return string the new hash. + */ + protected function _hashQuads($id, $bnodes, $namer) { + // return cached hash + if(property_exists($bnodes->{$id}, 'hash')) { + return $bnodes->{$id}->hash; + } + + // serialize all of bnode's quads + $quads = $bnodes->{$id}->quads; + $nquads = array(); + foreach($quads as $quad) { + $nquads[] = $this->toNQuad($quad, property_exists($quad, 'name') ? + $quad->name->value : null, $id); + } + + // sort serialized quads + sort($nquads); + + // cache and return hashed quads + $hash = $bnodes->{$id}->hash = sha1(implode($nquads)); + return $hash; + } + + /** + * Produces a hash for the paths of adjacent bnodes for a bnode, + * incorporating all information about its subgraph of bnodes. This + * method will recursively pick adjacent bnode permutations that produce the + * lexicographically-least 'path' serializations. + * + * @param string $id the ID of the bnode to hash paths for. + * @param stdClass $bnodes the map of bnode quads. + * @param UniqueNamer $namer the canonical bnode namer. + * @param UniqueNamer $path_namer the namer used to assign names to adjacent + * bnodes. + * + * @return stdClass the hash and path namer used. + */ + protected function _hashPaths($id, $bnodes, $namer, $path_namer) { + // create SHA-1 digest + $md = hash_init('sha1'); + + // group adjacent bnodes by hash, keep properties and references separate + $groups = new stdClass(); + $quads = $bnodes->{$id}->quads; + foreach($quads as $quad) { + // get adjacent bnode + $bnode = $this->_getAdjacentBlankNodeName($quad->subject, $id); + if($bnode !== null) { + // normal property + $direction = 'p'; + } else { + $bnode = $this->_getAdjacentBlankNodeName($quad->object, $id); + if($bnode !== null) { + // reverse property + $direction = 'r'; + } + } + if($bnode !== null) { + // get bnode name (try canonical, path, then hash) + if($namer->isNamed($bnode)) { + $name = $namer->getName($bnode); + } else if($path_namer->isNamed($bnode)) { + $name = $path_namer->getName($bnode); + } else { + $name = $this->_hashQuads($bnode, $bnodes, $namer); + } + + // hash direction, property, and bnode name/hash + $group_md = hash_init('sha1'); + hash_update($group_md, $direction); + hash_update($group_md, $quad->predicate->value); + hash_update($group_md, $name); + $group_hash = hash_final($group_md); + + // add bnode to hash group + if(property_exists($groups, $group_hash)) { + $groups->{$group_hash}[] = $bnode; + } else { + $groups->{$group_hash} = array($bnode); + } + } + } + + // iterate over groups in sorted hash order + $group_hashes = array_keys((array)$groups); + sort($group_hashes); + foreach($group_hashes as $group_hash) { + // digest group hash + hash_update($md, $group_hash); + + // choose a path and namer from the permutations + $chosen_path = null; + $chosen_namer = null; + $permutator = new Permutator($groups->{$group_hash}); + while($permutator->hasNext()) { + $permutation = $permutator->next(); + $path_namer_copy = clone $path_namer; + + // build adjacent path + $path = ''; + $skipped = false; + $recurse = array(); + foreach($permutation as $bnode) { + // use canonical name if available + if($namer->isNamed($bnode)) { + $path .= $namer->getName($bnode); + } else { + // recurse if bnode isn't named in the path yet + if(!$path_namer_copy->isNamed($bnode)) { + $recurse[] = $bnode; + } + $path .= $path_namer_copy->getName($bnode); + } + + // skip permutation if path is already >= chosen path + if($chosen_path !== null && strlen($path) >= strlen($chosen_path) && + $path > $chosen_path) { + $skipped = true; + break; + } + } + + // recurse + if(!$skipped) { + foreach($recurse as $bnode) { + $result = $this->_hashPaths( + $bnode, $bnodes, $namer, $path_namer_copy); + $path .= $path_namer_copy->getName($bnode); + $path .= "<{$result->hash}>"; + $path_namer_copy = $result->pathNamer; + + // skip permutation if path is already >= chosen path + if($chosen_path !== null && + strlen($path) >= strlen($chosen_path) && $path > $chosen_path) { + $skipped = true; + break; + } + } + } + + if(!$skipped && ($chosen_path === null || $path < $chosen_path)) { + $chosen_path = $path; + $chosen_namer = $path_namer_copy; + } + } + + // digest chosen path and update namer + hash_update($md, $chosen_path); + $path_namer = $chosen_namer; + } + + // return SHA-1 hash and path namer + return (object)array( + 'hash' => hash_final($md), 'pathNamer' => $path_namer); + } + + /** + * A helper function that gets the blank node name from an RDF quad + * node (subject or object). If the node is not a blank node or its + * value does not match the given blank node ID, it will be returned. + * + * @param stdClass $node the RDF quad node. + * @param string $id the ID of the blank node to look next to. + * + * @return mixed the adjacent blank node name or null if none was found. + */ + protected function _getAdjacentBlankNodeName($node, $id) { + if($node->type === 'blank node' && $node->value !== $id) { + return $node->value; + } + return null; + } + + /** + * Compares two strings first based on length and then lexicographically. + * + * @param string $a the first string. + * @param string $b the second string. + * + * @return integer -1 if a < b, 1 if a > b, 0 if a == b. + */ + protected function _compareShortestLeast($a, $b) { + $len_a = strlen($a); + $len_b = strlen($b); + if($len_a < $len_b) { + return -1; + } + if($len_b < $len_a) { + return 1; + } + if($a === $b) { + return 0; + } + return ($a < $b) ? -1 : 1; + } + + /** + * Picks the preferred compaction term from the given inverse context entry. + * + * @param active_ctx the active context. + * @param iri the IRI to pick the term for. + * @param value the value to pick the term for. + * @param containers the preferred containers. + * @param type_or_language either '@type' or '@language'. + * @param type_or_language_value the preferred value for '@type' or + * '@language'. + * + * @return mixed the preferred term. + */ + protected function _selectTerm( + $active_ctx, $iri, $value, $containers, + $type_or_language, $type_or_language_value) { + if($type_or_language_value === null) { + $type_or_language_value = '@null'; + } + + // options for the value of @type or @language + $prefs = array(); + + // determine prefs for @id based on whether or not value compacts to a term + if(($type_or_language_value === '@id' || + $type_or_language_value === '@reverse') && + self::_isSubjectReference($value)) { + // prefer @reverse first + if($type_or_language_value === '@reverse') { + $prefs[] = '@reverse'; + } + // try to compact value to a term + $term = $this->_compactIri( + $active_ctx, $value->{'@id'}, null, array('vocab' => true)); + if(property_exists($active_ctx->mappings, $term) && + $active_ctx->mappings->{$term} && + $active_ctx->mappings->{$term}->{'@id'} === $value->{'@id'}) { + // prefer @vocab + array_push($prefs, '@vocab', '@id'); + } else { + // prefer @id + array_push($prefs, '@id', '@vocab'); + } + } else { + $prefs[] = $type_or_language_value; + } + $prefs[] = '@none'; + + $container_map = $active_ctx->inverse->{$iri}; + foreach($containers as $container) { + // if container not available in the map, continue + if(!property_exists($container_map, $container)) { + continue; + } + + $type_or_language_value_map = + $container_map->{$container}->{$type_or_language}; + foreach($prefs as $pref) { + // if type/language option not available in the map, continue + if(!property_exists($type_or_language_value_map, $pref)) { + continue; + } + + // select term + return $type_or_language_value_map->{$pref}; + } + } + return null; + } + + /** + * Compacts an IRI or keyword into a term or prefix if it can be. If the + * IRI has an associated value it may be passed. + * + * @param stdClass $active_ctx the active context to use. + * @param string $iri the IRI to compact. + * @param mixed $value the value to check or null. + * @param assoc $relative_to options for how to compact IRIs: + * vocab: true to split after @vocab, false not to. + * @param bool $reverse true if a reverse property is being compacted, false + * if not. + * + * @return string the compacted term, prefix, keyword alias, or original IRI. + */ + protected function _compactIri( + $active_ctx, $iri, $value=null, $relative_to=array(), $reverse=false) { + // can't compact null + if($iri === null) { + return $iri; + } + + $inverse_ctx = $this->_getInverseContext($active_ctx); + + if(self::_isKeyword($iri)) { + // a keyword can only be compacted to simple alias + if(property_exists($inverse_ctx, $iri)) { + return $inverse_ctx->$iri->{'@none'}->{'@type'}->{'@none'}; + } + return $iri; + } + + if(!isset($relative_to['vocab'])) { + $relative_to['vocab'] = false; + } + + // use inverse context to pick a term if iri is relative to vocab + if($relative_to['vocab'] && property_exists($inverse_ctx, $iri)) { + $default_language = '@none'; + if(property_exists($active_ctx, '@language')) { + $default_language = $active_ctx->{'@language'}; + } + + // prefer @index if available in value + $containers = array(); + if(is_object($value) && property_exists($value, '@index')) { + $containers[] = '@index'; + } + + // defaults for term selection based on type/language + $type_or_language = '@language'; + $type_or_language_value = '@null'; + + if($reverse) { + $type_or_language = '@type'; + $type_or_language_value = '@reverse'; + $containers[] = '@set'; + } else if(self::_isList($value)) { + // choose the most specific term that works for all elements in @list + // only select @list containers if @index is NOT in value + if(!property_exists($value, '@index')) { + $containers[] = '@list'; + } + $list = $value->{'@list'}; + $common_language = (count($list) === 0) ? $default_language : null; + $common_type = null; + foreach($list as $item) { + $item_language = '@none'; + $item_type = '@none'; + if(self::_isValue($item)) { + if(property_exists($item, '@language')) { + $item_language = $item->{'@language'}; + } else if(property_exists($item, '@type')) { + $item_type = $item->{'@type'}; + } else { + // plain literal + $item_language = '@null'; + } + } else { + $item_type = '@id'; + } + if($common_language === null) { + $common_language = $item_language; + } else if($item_language !== $common_language && + self::_isValue($item)) { + $common_language = '@none'; + } + if($common_type === null) { + $common_type = $item_type; + } else if($item_type !== $common_type) { + $common_type = '@none'; + } + // there are different languages and types in the list, so choose + // the most generic term, no need to keep iterating the list + if($common_language === '@none' && $common_type === '@none') { + break; + } + } + if($common_language === null) { + $common_language = '@none'; + } + if($common_type === null) { + $common_type = '@none'; + } + if($common_type !== '@none') { + $type_or_language = '@type'; + $type_or_language_value = $common_type; + } else { + $type_or_language_value = $common_language; + } + } else { + if(self::_isValue($value)) { + if(property_exists($value, '@language') && + !property_exists($value, '@index')) { + $containers[] = '@language'; + $type_or_language_value = $value->{'@language'}; + } else if(property_exists($value, '@type')) { + $type_or_language = '@type'; + $type_or_language_value = $value->{'@type'}; + } + } else { + $type_or_language = '@type'; + $type_or_language_value = '@id'; + } + $containers[] = '@set'; + } + + // do term selection + $containers[] = '@none'; + $term = $this->_selectTerm( + $active_ctx, $iri, $value, + $containers, $type_or_language, $type_or_language_value); + if($term !== null) { + return $term; + } + } + + // no term match, use @vocab if available + if($relative_to['vocab']) { + if(property_exists($active_ctx, '@vocab')) { + // determine if vocab is a prefix of the iri + $vocab = $active_ctx->{'@vocab'}; + if(strpos($iri, $vocab) === 0 && $iri !== $vocab) { + // use suffix as relative iri if it is not a term in the active + // context + $suffix = substr($iri, strlen($vocab)); + if(!property_exists($active_ctx->mappings, $suffix)) { + return $suffix; + } + } + } + } + + // no term or @vocab match, check for possible CURIEs + $choice = null; + $idx = 0; + $partial_matches = array(); + $iri_map = $active_ctx->fast_curie_map; + // check for partial matches of against `iri`, which means look until + // iri.length - 1, not full length + $max_partial_length = strlen($iri) - 1; + for(; $idx < $max_partial_length && isset($iri_map[$iri[$idx]]); ++$idx) { + $iri_map = $iri_map[$iri[$idx]]; + if(isset($iri_map[''])) { + $entry = $iri_map[''][0]; + $entry->iri_length = $idx + 1; + $partial_matches[] = $entry; + } + } + // check partial matches in reverse order to prefer longest ones first + $partial_matches = array_reverse($partial_matches); + foreach($partial_matches as $entry) { + $terms = $entry->terms; + foreach($terms as $term) { + // a CURIE is usable if: + // 1. it has no mapping, OR + // 2. value is null, which means we're not compacting an @value, AND + // the mapping matches the IRI + $curie = $term . ':' . substr($iri, $entry->iri_length); + $is_usable_curie = (!property_exists($active_ctx->mappings, $curie) || + ($value === null && + $active_ctx->mappings->{$curie}->{'@id'} === $iri)); + + // select curie if it is shorter or the same length but + // lexicographically less than the current choice + if($is_usable_curie && ($choice === null || + self::_compareShortestLeast($curie, $choice) < 0)) { + $choice = $curie; + } + } + } + + // return chosen curie + if($choice !== null) { + return $choice; + } + + // compact IRI relative to base + if(!$relative_to['vocab']) { + return jsonld_remove_base($active_ctx->{'@base'}, $iri); + } + + // return IRI as is + return $iri; + } + + /** + * Performs value compaction on an object with '@value' or '@id' as the only + * property. + * + * @param stdClass $active_ctx the active context. + * @param string $active_property the active property that points to the + * value. + * @param mixed $value the value to compact. + * + * @return mixed the compaction result. + */ + protected function _compactValue($active_ctx, $active_property, $value) { + // value is a @value + if(self::_isValue($value)) { + // get context rules + $type = self::getContextValue($active_ctx, $active_property, '@type'); + $language = self::getContextValue( + $active_ctx, $active_property, '@language'); + $container = self::getContextValue( + $active_ctx, $active_property, '@container'); + + // whether or not the value has an @index that must be preserved + $preserve_index = (property_exists($value, '@index') && + $container !== '@index'); + + // if there's no @index to preserve + if(!$preserve_index) { + // matching @type or @language specified in context, compact value + if(self::_hasKeyValue($value, '@type', $type) || + self::_hasKeyValue($value, '@language', $language)) { + return $value->{'@value'}; + } + } + + // return just the value of @value if all are true: + // 1. @value is the only key or @index isn't being preserved + // 2. there is no default language or @value is not a string or + // the key has a mapping with a null @language + $key_count = count(array_keys((array)$value)); + $is_value_only_key = ($key_count === 1 || + ($key_count === 2 && property_exists($value, '@index') && + !$preserve_index)); + $has_default_language = property_exists($active_ctx, '@language'); + $is_value_string = is_string($value->{'@value'}); + $has_null_mapping = ( + property_exists($active_ctx->mappings, $active_property) && + $active_ctx->mappings->{$active_property} !== null && + self::_hasKeyValue( + $active_ctx->mappings->{$active_property}, '@language', null)); + if($is_value_only_key && + (!$has_default_language || !$is_value_string || $has_null_mapping)) { + return $value->{'@value'}; + } + + $rval = new stdClass(); + + // preserve @index + if($preserve_index) { + $rval->{$this->_compactIri($active_ctx, '@index')} = $value->{'@index'}; + } + + // compact @type IRI + if(property_exists($value, '@type')) { + $rval->{$this->_compactIri($active_ctx, '@type')} = $this->_compactIri( + $active_ctx, $value->{'@type'}, null, array('vocab' => true)); + } else if(property_exists($value, '@language')) { + // alias @language + $rval->{$this->_compactIri($active_ctx, '@language')} = + $value->{'@language'}; + } + + // alias @value + $rval->{$this->_compactIri($active_ctx, '@value')} = $value->{'@value'}; + + return $rval; + } + + // value is a subject reference + $expanded_property = $this->_expandIri( + $active_ctx, $active_property, array('vocab' => true)); + $type = self::getContextValue($active_ctx, $active_property, '@type'); + $compacted = $this->_compactIri( + $active_ctx, $value->{'@id'}, null, + array('vocab' => ($type === '@vocab'))); + + // compact to scalar + if($type === '@id' || $type === '@vocab' || + $expanded_property === '@graph') { + return $compacted; + } + + $rval = (object)array( + $this->_compactIri($active_ctx, '@id') => $compacted); + return $rval; + } + + /** + * Creates a term definition during context processing. + * + * @param stdClass $active_ctx the current active context. + * @param stdClass $local_ctx the local context being processed. + * @param string $term the key in the local context to define the mapping for. + * @param stdClass $defined a map of defining/defined keys to detect cycles + * and prevent double definitions. + */ + protected function _createTermDefinition( + $active_ctx, $local_ctx, $term, $defined) { + if(property_exists($defined, $term)) { + // term already defined + if($defined->{$term}) { + return; + } + // cycle detected + throw new JsonLdException( + 'Cyclical context definition detected.', + 'jsonld.CyclicalContext', 'cyclic IRI mapping', + array('context' => $local_ctx, 'term' => $term)); + } + + // now defining term + $defined->{$term} = false; + + if(self::_isKeyword($term)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; keywords cannot be overridden.', + 'jsonld.SyntaxError', 'keyword redefinition', + array('context' => $local_ctx, 'term' => $term)); + } + + // remove old mapping + if(property_exists($active_ctx->mappings, $term)) { + unset($active_ctx->mappings->{$term}); + } + + // get context term value + $value = $local_ctx->{$term}; + + // clear context entry + if($value === null || (is_object($value) && + self::_hasKeyValue($value, '@id', null))) { + $active_ctx->mappings->{$term} = null; + $defined->{$term} = true; + return; + } + + // convert short-hand value to object w/@id + if(is_string($value)) { + $value = (object)array('@id' => $value); + } + + if(!is_object($value)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context property values must be ' . + 'strings or objects.', 'jsonld.SyntaxError', 'invalid term definition', + array('context' => $local_ctx)); + } + + // create new mapping + $mapping = $active_ctx->mappings->{$term} = new stdClass(); + $mapping->reverse = false; + + if(property_exists($value, '@reverse')) { + if(property_exists($value, '@id')) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; a @reverse term definition must not ' + + 'contain @id.', 'jsonld.SyntaxError', 'invalid reverse property', + array('context' => $local_ctx)); + } + $reverse = $value->{'@reverse'}; + if(!is_string($reverse)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; a @context @reverse value must be a string.', + 'jsonld.SyntaxError', 'invalid IRI mapping', + array('context' => $local_ctx)); + } + + // expand and add @id mapping + $id = $this->_expandIri( + $active_ctx, $reverse, array('vocab' => true, 'base' => false), + $local_ctx, $defined); + if(!self::_isAbsoluteIri($id)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @reverse value must be ' . + 'an absolute IRI or a blank node identifier.', + 'jsonld.SyntaxError', 'invalid IRI mapping', + array('context' => $local_ctx)); + } + $mapping->{'@id'} = $id; + $mapping->reverse = true; + } else if(property_exists($value, '@id')) { + $id = $value->{'@id'}; + if(!is_string($id)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @id value must be a string.', + 'jsonld.SyntaxError', 'invalid IRI mapping', + array('context' => $local_ctx)); + } + if($id !== $term) { + // add @id to mapping + $id = $this->_expandIri( + $active_ctx, $id, array('vocab' => true, 'base' => false), + $local_ctx, $defined); + if(!self::_isAbsoluteIri($id) && !self::_isKeyword($id)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @id value must be an ' . + 'absolute IRI, a blank node identifier, or a keyword.', + 'jsonld.SyntaxError', 'invalid IRI mapping', + array('context' => $local_ctx)); + } + $mapping->{'@id'} = $id; + } + } + + // always compute whether term has a colon as an optimization for + // _compactIri + $colon = strpos($term, ':'); + $mapping->_term_has_colon = ($colon !== false); + + if(!property_exists($mapping, '@id')) { + // see if the term has a prefix + if($mapping->_term_has_colon) { + $prefix = substr($term, 0, $colon); + if(property_exists($local_ctx, $prefix)) { + // define parent prefix + $this->_createTermDefinition( + $active_ctx, $local_ctx, $prefix, $defined); + } + + if(property_exists($active_ctx->mappings, $prefix) && + $active_ctx->mappings->{$prefix}) { + // set @id based on prefix parent + $suffix = substr($term, $colon + 1); + $mapping->{'@id'} = $active_ctx->mappings->{$prefix}->{'@id'} . + $suffix; + } else { + // term is an absolute IRI + $mapping->{'@id'} = $term; + } + } else { + // non-IRIs *must* define @ids if @vocab is not available + if(!property_exists($active_ctx, '@vocab')) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context terms must define an @id.', + 'jsonld.SyntaxError', 'invalid IRI mapping', + array('context' => $local_ctx, 'term' => $term)); + } + // prepend vocab to term + $mapping->{'@id'} = $active_ctx->{'@vocab'} . $term; + } + } + + // optimization to store length of @id once for _compactIri + $mapping->_id_length = strlen($mapping->{'@id'}); + + // IRI mapping now defined + $defined->{$term} = true; + + if(property_exists($value, '@type')) { + $type = $value->{'@type'}; + if(!is_string($type)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @type values must be strings.', + 'jsonld.SyntaxError', 'invalid type mapping', + array('context' => $local_ctx)); + } + + if($type !== '@id' && $type !== '@vocab') { + // expand @type to full IRI + $type = $this->_expandIri( + $active_ctx, $type, array('vocab' => true), $local_ctx, $defined); + if(!self::_isAbsoluteIri($type)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; an @context @type value must ' . + 'be an absolute IRI.', 'jsonld.SyntaxError', + 'invalid type mapping', array('context' => $local_ctx)); + } + if(strpos($type, '_:') === 0) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; an @context @type values must ' . + 'be an IRI, not a blank node identifier.', + 'jsonld.SyntaxError', 'invalid type mapping', + array('context' => $local_ctx)); + } + } + + // add @type to mapping + $mapping->{'@type'} = $type; + } + + if(property_exists($value, '@container')) { + $container = $value->{'@container'}; + if($container !== '@list' && $container !== '@set' && + $container !== '@index' && $container !== '@language') { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @container value must be ' . + 'one of the following: @list, @set, @index, or @language.', + 'jsonld.SyntaxError', 'invalid container mapping', + array('context' => $local_ctx)); + } + if($mapping->reverse && $container !== '@index' && + $container !== '@set' && $container !== null) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @container value for a @reverse ' + + 'type definition must be @index or @set.', + 'jsonld.SyntaxError', 'invalid reverse property', + array('context' => $local_ctx)); + } + + // add @container to mapping + $mapping->{'@container'} = $container; + } + + if(property_exists($value, '@language') && + !property_exists($value, '@type')) { + $language = $value->{'@language'}; + if($language !== null && !is_string($language)) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context @language value must be ' . + 'a string or null.', 'jsonld.SyntaxError', + 'invalid language mapping', array('context' => $local_ctx)); + } + + // add @language to mapping + if($language !== null) { + $language = strtolower($language); + } + $mapping->{'@language'} = $language; + } + + // disallow aliasing @context and @preserve + $id = $mapping->{'@id'}; + if($id === '@context' || $id === '@preserve') { + throw new JsonLdException( + 'Invalid JSON-LD syntax; @context and @preserve cannot be aliased.', + 'jsonld.SyntaxError', 'invalid keyword alias', + array('context' => $local_ctx)); + } + } + + /** + * Expands a string to a full IRI. The string may be a term, a prefix, a + * relative IRI, or an absolute IRI. The associated absolute IRI will be + * returned. + * + * @param stdClass $active_ctx the current active context. + * @param string $value the string to expand. + * @param assoc $relative_to options for how to resolve relative IRIs: + * base: true to resolve against the base IRI, false not to. + * vocab: true to concatenate after @vocab, false not to. + * @param stdClass $local_ctx the local context being processed (only given + * if called during document processing). + * @param defined a map for tracking cycles in context definitions (only given + * if called during document processing). + * + * @return mixed the expanded value. + */ + function _expandIri( + $active_ctx, $value, $relative_to=array(), $local_ctx=null, $defined=null) { + // already expanded + if($value === null || self::_isKeyword($value)) { + return $value; + } + + // define term dependency if not defined + if($local_ctx !== null && property_exists($local_ctx, $value) && + !self::_hasKeyValue($defined, $value, true)) { + $this->_createTermDefinition($active_ctx, $local_ctx, $value, $defined); + } + + if(isset($relative_to['vocab']) && $relative_to['vocab']) { + if(property_exists($active_ctx->mappings, $value)) { + $mapping = $active_ctx->mappings->{$value}; + + // value is explicitly ignored with a null mapping + if($mapping === null) { + return null; + } + + // value is a term + return $mapping->{'@id'}; + } + } + + // split value into prefix:suffix + $colon = strpos($value, ':'); + if($colon !== false) { + $prefix = substr($value, 0, $colon); + $suffix = substr($value, $colon + 1); + + // do not expand blank nodes (prefix of '_') or already-absolute + // IRIs (suffix of '//') + if($prefix === '_' || strpos($suffix, '//') === 0) { + return $value; + } + + // prefix dependency not defined, define it + if($local_ctx !== null && property_exists($local_ctx, $prefix)) { + $this->_createTermDefinition( + $active_ctx, $local_ctx, $prefix, $defined); + } + + // use mapping if prefix is defined + if(property_exists($active_ctx->mappings, $prefix)) { + $mapping = $active_ctx->mappings->{$prefix}; + if($mapping) { + return $mapping->{'@id'} . $suffix; + } + } + + // already absolute IRI + return $value; + } + + // prepend vocab + if(isset($relative_to['vocab']) && $relative_to['vocab'] && + property_exists($active_ctx, '@vocab')) { + return $active_ctx->{'@vocab'} . $value; + } + + // prepend base + $rval = $value; + if(isset($relative_to['base']) && $relative_to['base']) { + $rval = jsonld_prepend_base($active_ctx->{'@base'}, $rval); + } + + return $rval; + } + + /** + * Finds all @context URLs in the given JSON-LD input. + * + * @param mixed $input the JSON-LD input. + * @param stdClass $urls a map of URLs (url => false/@contexts). + * @param bool $replace true to replace the URLs in the given input with + * the @contexts from the urls map, false not to. + * @param string $base the base URL to resolve relative URLs with. + */ + protected function _findContextUrls($input, $urls, $replace, $base) { + if(is_array($input)) { + foreach($input as $e) { + $this->_findContextUrls($e, $urls, $replace, $base); + } + } else if(is_object($input)) { + foreach($input as $k => &$v) { + if($k !== '@context') { + $this->_findContextUrls($v, $urls, $replace, $base); + continue; + } + + // array @context + if(is_array($v)) { + $length = count($v); + for($i = 0; $i < $length; ++$i) { + if(is_string($v[$i])) { + $url = jsonld_prepend_base($base, $v[$i]); + // replace w/@context if requested + if($replace) { + $ctx = $urls->{$url}; + if(is_array($ctx)) { + // add flattened context + array_splice($v, $i, 1, $ctx); + $i += count($ctx) - 1; + $length = count($v); + } else { + $v[$i] = $ctx; + } + } else if(!property_exists($urls, $url)) { + // @context URL found + $urls->{$url} = false; + } + } + } + } else if(is_string($v)) { + // string @context + $v = jsonld_prepend_base($base, $v); + // replace w/@context if requested + if($replace) { + $input->{$k} = $urls->{$v}; + } else if(!property_exists($urls, $v)) { + // @context URL found + $urls->{$v} = false; + } + } + } + } + } + + /** + * Retrieves external @context URLs using the given document loader. Each + * instance of @context in the input that refers to a URL will be replaced + * with the JSON @context found at that URL. + * + * @param mixed $input the JSON-LD input with possible contexts. + * @param stdClass $cycles an object for tracking context cycles. + * @param callable $load_document(url) the document loader. + * @param base $base the base URL to resolve relative URLs against. + * + * @return mixed the result. + */ + protected function _retrieveContextUrls( + &$input, $cycles, $load_document, $base='') { + if(count(get_object_vars($cycles)) > self::MAX_CONTEXT_URLS) { + throw new JsonLdException( + 'Maximum number of @context URLs exceeded.', + 'jsonld.ContextUrlError', 'loading remote context failed', + array('max' => self::MAX_CONTEXT_URLS)); + } + + // for tracking the URLs to retrieve + $urls = new stdClass(); + + // regex for validating URLs + $regex = '/(http|https):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/'; + + // find all URLs in the given input + $this->_findContextUrls($input, $urls, false, $base); + + // queue all unretrieved URLs + $queue = array(); + foreach($urls as $url => $ctx) { + if($ctx === false) { + // validate URL + if(!preg_match($regex, $url)) { + throw new JsonLdException( + 'Malformed or unsupported URL.', 'jsonld.InvalidUrl', + 'loading remote context failed', array('url' => $url)); + } + $queue[] = $url; + } + } + + // retrieve URLs in queue + foreach($queue as $url) { + // check for context URL cycle + if(property_exists($cycles, $url)) { + throw new JsonLdException( + 'Cyclical @context URLs detected.', + 'jsonld.ContextUrlError', 'recursive context inclusion', + array('url' => $url)); + } + $_cycles = self::copy($cycles); + $_cycles->{$url} = true; + + // retrieve URL + $remote_doc = call_user_func($load_document, $url); + $ctx = $remote_doc->document; + + // parse string context as JSON + if(is_string($ctx)) { + try { + $ctx = self::_parse_json($ctx); + } catch(Exception $e) { + throw new JsonLdException( + 'Could not parse JSON from URL.', + 'jsonld.ParseError', 'loading remote context failed', + array('url' => $url), $e); + } + } + + // ensure ctx is an object + if(!is_object($ctx)) { + throw new JsonLdException( + 'Derefencing a URL did not result in a valid JSON-LD object.', + 'jsonld.InvalidUrl', 'invalid remote context', array('url' => $url)); + } + + // use empty context if no @context key is present + if(!property_exists($ctx, '@context')) { + $ctx = (object)array('@context' => new stdClass()); + } else { + $ctx = (object)array('@context' => $ctx->{'@context'}); + } + + // append context URL to context if given + if($remote_doc->contextUrl !== null) { + $ctx->{'@context'} = self::arrayify($ctx->{'@context'}); + $ctx->{'@context'}[] = $remote_doc->contextUrl; + } + + // recurse + $this->_retrieveContextUrls($ctx, $_cycles, $load_document, $url); + $urls->{$url} = $ctx->{'@context'}; + } + + // replace all URLS in the input + $this->_findContextUrls($input, $urls, true, $base); + } + + /** + * Gets the initial context. + * + * @param assoc $options the options to use. + * base the document base IRI. + * + * @return stdClass the initial context. + */ + protected function _getInitialContext($options) { + return (object)array( + '@base' => jsonld_parse_url($options['base']), + 'mappings' => new stdClass(), + 'inverse' => null); + } + + /** + * Generates an inverse context for use in the compaction algorithm, if + * not already generated for the given active context. + * + * @param stdClass $active_ctx the active context to use. + * + * @return stdClass the inverse context. + */ + protected function _getInverseContext($active_ctx) { + // inverse context already generated + if($active_ctx->inverse) { + return $active_ctx->inverse; + } + + $inverse = $active_ctx->inverse = new stdClass(); + + // variables for building fast CURIE map + $fast_curie_map = $active_ctx->fast_curie_map = new ArrayObject(); + $iris_to_terms = array(); + + // handle default language + $default_language = '@none'; + if(property_exists($active_ctx, '@language')) { + $default_language = $active_ctx->{'@language'}; + } + + // create term selections for each mapping in the context, ordered by + // shortest and then lexicographically least + $mappings = $active_ctx->mappings; + $terms = array_keys((array)$mappings); + usort($terms, array($this, '_compareShortestLeast')); + foreach($terms as $term) { + $mapping = $mappings->{$term}; + if($mapping === null) { + continue; + } + + // add term selection where it applies + if(property_exists($mapping, '@container')) { + $container = $mapping->{'@container'}; + } else { + $container = '@none'; + } + + // iterate over every IRI in the mapping + $iris = $mapping->{'@id'}; + $iris = self::arrayify($iris); + foreach($iris as $iri) { + $is_keyword = self::_isKeyword($iri); + + // initialize container map + if(!property_exists($inverse, $iri)) { + $inverse->{$iri} = new stdClass(); + if(!$is_keyword && !$mapping->_term_has_colon) { + // init IRI to term map and fast CURIE map + $iris_to_terms[$iri] = new ArrayObject(); + $iris_to_terms[$iri][] = $term; + $fast_curie_entry = (object)array( + 'iri' => $iri, 'terms' => $iris_to_terms[$iri]); + if(!array_key_exists($iri[0], (array)$fast_curie_map)) { + $fast_curie_map[$iri[0]] = new ArrayObject(); + } + $fast_curie_map[$iri[0]][] = $fast_curie_entry; + } + } else if(!$is_keyword && !$mapping->_term_has_colon) { + // add IRI to term match + $iris_to_terms[$iri][] = $term; + } + $container_map = $inverse->{$iri}; + + // add new entry + if(!property_exists($container_map, $container)) { + $container_map->{$container} = (object)array( + '@language' => new stdClass(), + '@type' => new stdClass()); + } + $entry = $container_map->{$container}; + + if($mapping->reverse) { + // term is preferred for values using @reverse + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@type'}, '@reverse'); + } else if(property_exists($mapping, '@type')) { + // term is preferred for values using specific type + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@type'}, $mapping->{'@type'}); + } else if(property_exists($mapping, '@language')) { + // term is preferred for values using specific language + $language = $mapping->{'@language'}; + if($language === null) { + $language = '@null'; + } + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@language'}, $language); + } else { + // term is preferred for values w/default language or no type and + // no language + // add an entry for the default language + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@language'}, $default_language); + + // add entries for no type and no language + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@type'}, '@none'); + $this->_addPreferredTerm( + $mapping, $term, $entry->{'@language'}, '@none'); + } + } + } + + // build fast CURIE map + foreach($fast_curie_map as $key => $value) { + $this->_buildIriMap($fast_curie_map, $key, 1); + } + + return $inverse; + } + + /** + * Runs a recursive algorithm to build a lookup map for quickly finding + * potential CURIEs. + * + * @param ArrayObject $iri_map the map to build. + * @param string $key the current key in the map to work on. + * @param int $idx the index into the IRI to compare. + */ + function _buildIriMap($iri_map, $key, $idx) { + $entries = $iri_map[$key]; + $next = $iri_map[$key] = new ArrayObject(); + + foreach($entries as $entry) { + $iri = $entry->iri; + if($idx >= strlen($iri)) { + $letter = ''; + } else { + $letter = $iri[$idx]; + } + if(!isset($next[$letter])) { + $next[$letter] = new ArrayObject(); + } + $next[$letter][] = $entry; + } + + foreach($next as $key => $value) { + if($key === '') { + continue; + } + $this->_buildIriMap($next, $key, $idx + 1); + } + } + + /** + * Adds the term for the given entry if not already added. + * + * @param stdClass $mapping the term mapping. + * @param string $term the term to add. + * @param stdClass $entry the inverse context type_or_language entry to + * add to. + * @param string $type_or_language_value the key in the entry to add to. + */ + function _addPreferredTerm($mapping, $term, $entry, $type_or_language_value) { + if(!property_exists($entry, $type_or_language_value)) { + $entry->{$type_or_language_value} = $term; + } + } + + /** + * Clones an active context, creating a child active context. + * + * @return stdClass a clone (child) of the active context. + */ + protected function _cloneActiveContext($active_ctx) { + $child = new stdClass(); + $child->{'@base'} = $active_ctx->{'@base'}; + $child->mappings = self::copy($active_ctx->mappings); + $child->inverse = null; + if(property_exists($active_ctx, '@language')) { + $child->{'@language'} = $active_ctx->{'@language'}; + } + if(property_exists($active_ctx, '@vocab')) { + $child->{'@vocab'} = $active_ctx->{'@vocab'}; + } + return $child; + } + + /** + * Returns whether or not the given value is a keyword. + * + * @param string $v the value to check. + * + * @return bool true if the value is a keyword, false if not. + */ + protected static function _isKeyword($v) { + if(!is_string($v)) { + return false; + } + switch($v) { + case '@base': + case '@context': + case '@container': + case '@default': + case '@embed': + case '@explicit': + case '@graph': + case '@id': + case '@index': + case '@language': + case '@list': + case '@omitDefault': + case '@preserve': + case '@requireAll': + case '@reverse': + case '@set': + case '@type': + case '@value': + case '@vocab': + return true; + } + return false; + } + + /** + * Returns true if the given value is an empty Object. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is an empty Object, false if not. + */ + protected static function _isEmptyObject($v) { + return is_object($v) && count(get_object_vars($v)) === 0; + } + + /** + * Throws an exception if the given value is not a valid @type value. + * + * @param mixed $v the value to check. + */ + protected static function _validateTypeValue($v) { + // must be a string or empty object + if(is_string($v) || self::_isEmptyObject($v)) { + return; + } + + // must be an array + $is_valid = false; + if(is_array($v)) { + // must contain only strings + $is_valid = true; + foreach($v as $e) { + if(!(is_string($e))) { + $is_valid = false; + break; + } + } + } + + if(!$is_valid) { + throw new JsonLdException( + 'Invalid JSON-LD syntax; "@type" value must a string, an array ' . + 'of strings, or an empty object.', + 'jsonld.SyntaxError', 'invalid type value', array('value' => $v)); + } + } + + /** + * Returns true if the given value is a subject with properties. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is a subject with properties, false if not. + */ + protected static function _isSubject($v) { + // Note: A value is a subject if all of these hold true: + // 1. It is an Object. + // 2. It is not a @value, @set, or @list. + // 3. It has more than 1 key OR any existing key is not @id. + $rval = false; + if(is_object($v) && + !property_exists($v, '@value') && + !property_exists($v, '@set') && + !property_exists($v, '@list')) { + $count = count(get_object_vars($v)); + $rval = ($count > 1 || !property_exists($v, '@id')); + } + return $rval; + } + + /** + * Returns true if the given value is a subject reference. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is a subject reference, false if not. + */ + protected static function _isSubjectReference($v) { + // Note: A value is a subject reference if all of these hold true: + // 1. It is an Object. + // 2. It has a single key: @id. + return (is_object($v) && count(get_object_vars($v)) === 1 && + property_exists($v, '@id')); + } + + /** + * Returns true if the given value is a @value. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is a @value, false if not. + */ + protected static function _isValue($v) { + // Note: A value is a @value if all of these hold true: + // 1. It is an Object. + // 2. It has the @value property. + return is_object($v) && property_exists($v, '@value'); + } + + /** + * Returns true if the given value is a @list. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is a @list, false if not. + */ + protected static function _isList($v) { + // Note: A value is a @list if all of these hold true: + // 1. It is an Object. + // 2. It has the @list property. + return is_object($v) && property_exists($v, '@list'); + } + + /** + * Returns true if the given value is a blank node. + * + * @param mixed $v the value to check. + * + * @return bool true if the value is a blank node, false if not. + */ + protected static function _isBlankNode($v) { + // Note: A value is a blank node if all of these hold true: + // 1. It is an Object. + // 2. If it has an @id key its value begins with '_:'. + // 3. It has no keys OR is not a @value, @set, or @list. + $rval = false; + if(is_object($v)) { + if(property_exists($v, '@id')) { + $rval = (strpos($v->{'@id'}, '_:') === 0); + } else { + $rval = (count(get_object_vars($v)) === 0 || + !(property_exists($v, '@value') || + property_exists($v, '@set') || + property_exists($v, '@list'))); + } + } + return $rval; + } + + /** + * Returns true if the given value is an absolute IRI, false if not. + * + * @param string $v the value to check. + * + * @return bool true if the value is an absolute IRI, false if not. + */ + protected static function _isAbsoluteIri($v) { + return strpos($v, ':') !== false; + } + + /** + * Returns true if the given target has the given key and its + * value equals is the given value. + * + * @param stdClass $target the target object. + * @param string key the key to check. + * @param mixed $value the value to check. + * + * @return bool true if the target has the given key and its value matches. + */ + protected static function _hasKeyValue($target, $key, $value) { + return (property_exists($target, $key) && $target->{$key} === $value); + } + + /** + * Returns true if both of the given objects have the same value for the + * given key or if neither of the objects contain the given key. + * + * @param stdClass $o1 the first object. + * @param stdClass $o2 the second object. + * @param string key the key to check. + * + * @return bool true if both objects have the same value for the key or + * neither has the key. + */ + protected static function _compareKeyValues($o1, $o2, $key) { + if(property_exists($o1, $key)) { + return property_exists($o2, $key) && $o1->{$key} === $o2->{$key}; + } + return !property_exists($o2, $key); + } + + /** + * Parses JSON and sets an appropriate exception message on error. + * + * @param string $json the JSON to parse. + * + * @return mixed the parsed JSON object or array. + */ + protected static function _parse_json($json) { + $rval = json_decode($json); + $error = json_last_error(); + if($error === JSON_ERROR_NONE && $rval === null) { + $error = JSON_ERROR_SYNTAX; + } + switch($error) { + case JSON_ERROR_NONE: + break; + case JSON_ERROR_DEPTH: + throw new JsonLdException( + 'Could not parse JSON; the maximum stack depth has been exceeded.', + 'jsonld.ParseError'); + case JSON_ERROR_STATE_MISMATCH: + throw new JsonLdException( + 'Could not parse JSON; invalid or malformed JSON.', + 'jsonld.ParseError'); + case JSON_ERROR_CTRL_CHAR: + case JSON_ERROR_SYNTAX: + throw new JsonLdException( + 'Could not parse JSON; syntax error, malformed JSON.', + 'jsonld.ParseError'); + case JSON_ERROR_UTF8: + throw new JsonLdException( + 'Could not parse JSON from URL; malformed UTF-8 characters.', + 'jsonld.ParseError'); + default: + throw new JsonLdException( + 'Could not parse JSON from URL; unknown error.', + 'jsonld.ParseError'); + } + return $rval; + } +} + +// register the N-Quads RDF parser +jsonld_register_rdf_parser( + 'application/nquads', array('JsonLdProcessor', 'parseNQuads')); + +/** + * A JSON-LD Exception. + */ +class JsonLdException extends Exception { + public function __construct( + $msg, $type, $code='error', $details=null, $previous=null) { + $this->type = $type; + $this->code = $code; + $this->details = $details; + $this->cause = $previous; + parent::__construct($msg, 0, $previous); + } + public function __toString() { + $rval = __CLASS__ . ": [{$this->type}]: {$this->message}\n"; + if($this->code) { + $rval .= 'Code: ' . $this->code . "\n"; + } + if($this->details) { + $rval .= 'Details: ' . print_r($this->details, true) . "\n"; + } + if($this->cause) { + $rval .= 'Cause: ' . $this->cause; + } + $rval .= $this->getTraceAsString() . "\n"; + return $rval; + } +}; + +/** + * A UniqueNamer issues unique names, keeping track of any previously issued + * names. + */ +class UniqueNamer { + /** + * Constructs a new UniqueNamer. + * + * @param prefix the prefix to use (''). + */ + public function __construct($prefix) { + $this->prefix = $prefix; + $this->counter = 0; + $this->existing = new stdClass(); + $this->order = array(); + } + + /** + * Clones this UniqueNamer. + */ + public function __clone() { + $this->existing = clone $this->existing; + } + + /** + * Gets the new name for the given old name, where if no old name is given + * a new name will be generated. + * + * @param mixed [$old_name] the old name to get the new name for. + * + * @return string the new name. + */ + public function getName($old_name=null) { + // return existing old name + if($old_name && property_exists($this->existing, $old_name)) { + return $this->existing->{$old_name}; + } + + // get next name + $name = $this->prefix . $this->counter; + $this->counter += 1; + + // save mapping + if($old_name !== null) { + $this->existing->{$old_name} = $name; + $this->order[] = $old_name; + } + + return $name; + } + + /** + * Returns true if the given old name has already been assigned a new name. + * + * @param string $old_name the old name to check. + * + * @return true if the old name has been assigned a new name, false if not. + */ + public function isNamed($old_name) { + return property_exists($this->existing, $old_name); + } +} + +/** + * A Permutator iterates over all possible permutations of the given array + * of elements. + */ +class Permutator { + /** + * Constructs a new Permutator. + * + * @param array $list the array of elements to iterate over. + */ + public function __construct($list) { + // original array + $this->list = $list; + sort($this->list); + // indicates whether there are more permutations + $this->done = false; + // directional info for permutation algorithm + $this->left = new stdClass(); + foreach($list as $v) { + $this->left->{$v} = true; + } + } + + /** + * Returns true if there is another permutation. + * + * @return bool true if there is another permutation, false if not. + */ + public function hasNext() { + return !$this->done; + } + + /** + * Gets the next permutation. Call hasNext() to ensure there is another one + * first. + * + * @return array the next permutation. + */ + public function next() { + // copy current permutation + $rval = $this->list; + + /* Calculate the next permutation using the Steinhaus-Johnson-Trotter + permutation algorithm. */ + + // get largest mobile element k + // (mobile: element is greater than the one it is looking at) + $k = null; + $pos = 0; + $length = count($this->list); + for($i = 0; $i < $length; ++$i) { + $element = $this->list[$i]; + $left = $this->left->{$element}; + if(($k === null || $element > $k) && + (($left && $i > 0 && $element > $this->list[$i - 1]) || + (!$left && $i < ($length - 1) && $element > $this->list[$i + 1]))) { + $k = $element; + $pos = $i; + } + } + + // no more permutations + if($k === null) { + $this->done = true; + } else { + // swap k and the element it is looking at + $swap = $this->left->{$k} ? $pos - 1 : $pos + 1; + $this->list[$pos] = $this->list[$swap]; + $this->list[$swap] = $k; + + // reverse the direction of all elements larger than k + for($i = 0; $i < $length; ++$i) { + if($this->list[$i] > $k) { + $this->left->{$this->list[$i]} = !$this->left->{$this->list[$i]}; + } + } + } + + return $rval; + } +} + +/** + * An ActiveContextCache caches active contexts so they can be reused without + * the overhead of recomputing them. + */ +class ActiveContextCache { + /** + * Constructs a new ActiveContextCache. + * + * @param int size the maximum size of the cache, defaults to 100. + */ + public function __construct($size=100) { + $this->order = array(); + $this->cache = new stdClass(); + $this->size = $size; + } + + /** + * Gets an active context from the cache based on the current active + * context and the new local context. + * + * @param stdClass $active_ctx the current active context. + * @param stdClass $local_ctx the new local context. + * + * @return mixed a shared copy of the cached active context or null. + */ + public function get($active_ctx, $local_ctx) { + $key1 = serialize($active_ctx); + $key2 = serialize($local_ctx); + if(property_exists($this->cache, $key1)) { + $level1 = $this->cache->{$key1}; + if(property_exists($level1, $key2)) { + return $level1->{$key2}; + } + } + return null; + } + + /** + * Sets an active context in the cache based on the previous active + * context and the just-processed local context. + * + * @param stdClass $active_ctx the previous active context. + * @param stdClass $local_ctx the just-processed local context. + * @param stdClass $result the resulting active context. + */ + public function set($active_ctx, $local_ctx, $result) { + if(count($this->order) === $this->size) { + $entry = array_shift($this->order); + unset($this->cache->{$entry->activeCtx}->{$entry->localCtx}); + } + $key1 = serialize($active_ctx); + $key2 = serialize($local_ctx); + $this->order[] = (object)array( + 'activeCtx' => $key1, 'localCtx' => $key2); + if(!property_exists($this->cache, $key1)) { + $this->cache->{$key1} = new stdClass(); + } + $this->cache->{$key1}->{$key2} = JsonLdProcessor::copy($result); + } +} + +/* end of file, omit ?> */ diff --git a/library/jsonld/test.php b/library/jsonld/test.php new file mode 100644 index 000000000..11b72ac09 --- /dev/null +++ b/library/jsonld/test.php @@ -0,0 +1,765 @@ +attach($result); + $this->result = $result; + parent::run($result); + } + + /** + * Tests expansion. + * + * @param JsonLdTest $test the test to run. + * + * @group expand + * @group json-ld.org + * @dataProvider expandProvider + */ + public function testExpand($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $options = $test->createOptions(); + $test->run('jsonld_expand', array($input, $options)); + } + + /** + * Tests compaction. + * + * @param JsonLdTest $test the test to run. + * + * @group compact + * @group json-ld.org + * @dataProvider compactProvider + */ + public function testCompact($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $context = $test->readProperty('context'); + $options = $test->createOptions(); + $test->run('jsonld_compact', array($input, $context, $options)); + } + + /** + * Tests flatten. + * + * @param JsonLdTest $test the test to run. + * + * @group flatten + * @group json-ld.org + * @dataProvider flattenProvider + */ + public function testFlatten($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $context = $test->readProperty('context'); + $options = $test->createOptions(); + $test->run('jsonld_flatten', array($input, $context, $options)); + } + + /** + * Tests serialization to RDF. + * + * @param JsonLdTest $test the test to run. + * + * @group toRdf + * @group json-ld.org + * @dataProvider toRdfProvider + */ + public function testToRdf($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $options = $test->createOptions(array('format' => 'application/nquads')); + $test->run('jsonld_to_rdf', array($input, $options)); + } + + /** + * Tests deserialization from RDF. + * + * @param JsonLdTest $test the test to run. + * + * @group fromRdf + * @group json-ld.org + * @dataProvider fromRdfProvider + */ + public function testFromRdf($test) { + $this->test = $test; + $input = $test->readProperty('input'); + $options = $test->createOptions(array('format' => 'application/nquads')); + $test->run('jsonld_from_rdf', array($input, $options)); + } + + /** + * Tests framing. + * + * @param JsonLdTest $test the test to run. + * + * @group frame + * @group json-ld.org + * @dataProvider frameProvider + */ + public function testFrame($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $frame = $test->readProperty('frame'); + $options = $test->createOptions(); + $test->run('jsonld_frame', array($input, $frame, $options)); + } + + /** + * Tests normalization. + * + * @param JsonLdTest $test the test to run. + * + * @group normalize + * @group json-ld.org + * @dataProvider normalizeProvider + */ + public function testNormalize($test) { + $this->test = $test; + $input = $test->readUrl('input'); + $options = $test->createOptions(array('format' => 'application/nquads')); + $test->run('jsonld_normalize', array($input, $options)); + } + + /** + * Tests URGNA2012 normalization. + * + * @param JsonLdTest $test the test to run. + * + * @group normalize + * @group normalization + * @dataProvider urgna2012Provider + */ + public function testUrgna2012($test) { + $this->test = $test; + $input = $test->readProperty('action'); + $options = $test->createOptions(array( + 'algorithm' => 'URGNA2012', + 'inputFormat' => 'application/nquads', + 'format' => 'application/nquads')); + $test->run('jsonld_normalize', array($input, $options)); + } + + /** + * Tests URDNA2015 normalization. + * + * @param JsonLdTest $test the test to run. + * + * @group normalize + * @group normalization + * @dataProvider urdna2015Provider + */ + public function testUrdna2015($test) { + $this->test = $test; + $input = $test->readProperty('action'); + $options = $test->createOptions(array( + 'algorithm' => 'URDNA2015', + 'inputFormat' => 'application/nquads', + 'format' => 'application/nquads')); + $test->run('jsonld_normalize', array($input, $options)); + } + + public function expandProvider() { + return new JsonLdTestIterator('jld:ExpandTest'); + } + + public function compactProvider() { + return new JsonLdTestIterator('jld:CompactTest'); + } + + public function flattenProvider() { + return new JsonLdTestIterator('jld:FlattenTest'); + } + + public function toRdfProvider() { + return new JsonLdTestIterator('jld:ToRDFTest'); + } + + public function fromRdfProvider() { + return new JsonLdTestIterator('jld:FromRDFTest'); + } + + public function normalizeProvider() { + return new JsonLdTestIterator('jld:NormalizeTest'); + } + + public function frameProvider() { + return new JsonLdTestIterator('jld:FrameTest'); + } + + public function urgna2012Provider() { + return new JsonLdTestIterator('rdfn:Urgna2012EvalTest'); + } + + public function urdna2015Provider() { + return new JsonLdTestIterator('rdfn:Urdna2015EvalTest'); + } +} + +class JsonLdManifest { + public function __construct($data, $filename) { + $this->data = $data; + $this->filename = $filename; + $this->dirname = dirname($filename); + } + + public function load(&$tests) { + $entries = array_merge( + JsonLdProcessor::getValues($this->data, 'sequence'), + JsonLdProcessor::getValues($this->data, 'entries')); + $includes = JsonLdProcessor::getValues($this->data, 'include'); + foreach($includes as $include) { + array_push($entries, $include . '.jsonld'); + } + foreach($entries as $entry) { + if(is_string($entry)) { + $filename = join( + DIRECTORY_SEPARATOR, array($this->dirname, $entry)); + $entry = Util::readJson($filename); + } else { + $filename = $this->filename; + } + + if(JsonLdProcessor::hasValue($entry, '@type', 'mf:Manifest') || + JsonLdProcessor::hasValue($entry, 'type', 'mf:Manifest')) { + // entry is another manifest + $manifest = new JsonLdManifest($entry, $filename); + $manifest->load($tests); + } else { + // assume entry is a test + $test = new JsonLdTest($this, $entry, $filename); + $types = array_merge( + JsonLdProcessor::getValues($test->data, '@type'), + JsonLdProcessor::getValues($test->data, 'type')); + foreach($types as $type) { + if(!isset($tests[$type])) { + $tests[$type] = array(); + } + $tests[$type][] = $test; + } + } + } + } +} + +class JsonLdTest { + public function __construct($manifest, $data, $filename) { + $this->manifest = $manifest; + $this->data = $data; + $this->filename = $filename; + $this->dirname = dirname($filename); + $this->isPositive = + JsonLdProcessor::hasValue( + $data, '@type', 'jld:PositiveEvaluationTest') || + JsonLdProcessor::hasValue( + $data, 'type', 'jld:PositiveEvaluationTest'); + $this->isNegative = + JsonLdProcessor::hasValue( + $data, '@type', 'jld:NegativeEvaluationTest') || + JsonLdProcessor::hasValue( + $data, 'type', 'jld:NegativeEvaluationTest'); + + // generate test name + if(isset($manifest->data->name)) { + $manifestLabel = $manifest->data->name; + } else if(isset($manifest->data->label)) { + $manifestLabel = $manifest->data->label; + } else { + $manifestLabel = 'UNNAMED'; + } + if(isset($this->data->id)) { + $testId = $this->data->id; + } else { + $testId = $this->data->{'@id'}; + } + if(isset($this->data->name)) { + $testLabel = $this->data->name; + } else if(isset($this->data->label)) { + $testLabel = $this->data->label; + } else { + $testLabel = 'UNNAMED'; + } + + $this->name = $manifestLabel . ' ' . $testId . ' - ' . $testLabel; + + // expand @id and input base + if(isset($manifest->data->baseIri)) { + $data->{'@id'} = ($manifest->data->baseIri . + basename($manifest->filename) . $data->{'@id'}); + $this->base = $manifest->data->baseIri . $data->input; + } + } + + private function _getResultProperty() { + if(isset($this->data->expect)) { + return 'expect'; + } else if(isset($this->data->result)) { + return 'result'; + } else { + throw new Exception('No test result property found.'); + } + } + + public function run($fn, $params) { + // read expected data + if($this->isNegative) { + $this->expected = $this->data->expect; + } else { + $this->expected = $this->readProperty($this->_getResultProperty()); + } + + try { + $this->actual = call_user_func_array($fn, $params); + if($this->isNegative) { + throw new Exception('Expected an error; one was not raised.'); + } + PHPUnit_Framework_TestCase::assertEquals($this->expected, $this->actual); + } catch(Exception $e) { + // assume positive test + if($this->isNegative) { + $this->actual = $this->getJsonLdErrorCode($e); + PHPUnit_Framework_TestCase::assertEquals( + $this->expected, $this->actual); + } else { + throw $e; + } + } + } + + public function readUrl($property) { + if(!property_exists($this->data, $property)) { + return null; + } + return $this->manifest->data->baseIri . $this->data->{$property}; + } + + public function readProperty($property) { + $data = $this->data; + if(!property_exists($data, $property)) { + return null; + } + $filename = join( + DIRECTORY_SEPARATOR, array($this->dirname, $data->{$property})); + $extension = pathinfo($filename, PATHINFO_EXTENSION); + if($extension === 'jsonld') { + return Util::readJson($filename); + } + return Util::readFile($filename); + } + + public function createOptions($opts=array()) { + $http_options = array( + 'contentType', 'httpLink', 'httpStatus', 'redirectTo'); + $test_options = (property_exists($this->data, 'option') ? + $this->data->option : array()); + $options = array(); + foreach($test_options as $k => $v) { + if(!in_array($k, $http_options)) { + $options[$k] = $v; + } + } + $options['documentLoader'] = $this->createDocumentLoader(); + $options = array_merge($options, $opts); + if(isset($options['expandContext'])) { + $filename = join( + DIRECTORY_SEPARATOR, array($this->dirname, $options['expandContext'])); + $options['expandContext'] = Util::readJson($filename); + } + return $options; + } + + public function createDocumentLoader() { + $base = 'http://json-ld.org/test-suite'; + $test = $this; + + $load_locally = function($url) use ($test, $base) { + $doc = (object)array( + 'contextUrl' => null, 'documentUrl' => $url, 'document' => null); + $options = (property_exists($test->data, 'option') ? + $test->data->option : null); + if($options and $url === $test->base) { + if(property_exists($options, 'redirectTo') && + property_exists($options, 'httpStatus') && + $options->httpStatus >= '300') { + $doc->documentUrl = ($test->manifest->data->baseIri . + $options->redirectTo); + } else if(property_exists($options, 'httpLink')) { + $content_type = (property_exists($options, 'contentType') ? + $options->contentType : null); + $extension = pathinfo($url, PATHINFO_EXTENSION); + if(!$content_type && $extension === 'jsonld') { + $content_type = 'application/ld+json'; + } + $link_header = $options->httpLink; + if(is_array($link_header)) { + $link_header = join(',', $link_header); + } + $link_header = jsonld_parse_link_header($link_header); + if(isset($link_header['http://www.w3.org/ns/json-ld#context'])) { + $link_header = $link_header['http://www.w3.org/ns/json-ld#context']; + } else { + $link_header = null; + } + if($link_header && $content_type !== 'application/ld+json') { + if(is_array($link_header)) { + throw new Exception('multiple context link headers'); + } + $doc->contextUrl = $link_header->target; + } + } + } + global $ROOT_MANIFEST_DIR; + if(strpos($doc->documentUrl, ':') === false) { + $filename = join( + DIRECTORY_SEPARATOR, array( + $ROOT_MANIFEST_DIR, $doc->documentUrl)); + $doc->documentUrl = 'file://' . $filename; + } else { + $filename = join( + DIRECTORY_SEPARATOR, array( + $ROOT_MANIFEST_DIR, substr($doc->documentUrl, strlen($base)))); + } + try { + $doc->document = Util::readJson($filename); + } catch(Exception $e) { + throw new Exception('loading document failed'); + } + return $doc; + }; + + $local_loader = function($url) use ($test, $base, $load_locally) { + // always load remote-doc and non-base tests remotely + if((strpos($url, $base) !== 0 && strpos($url, ':') !== false) || + $test->manifest->data->name === 'Remote document') { + return call_user_func('jsonld_default_document_loader', $url); + } + + // attempt to load locally + return call_user_func($load_locally, $url); + }; + + return $local_loader; + } + + public function getJsonLdErrorCode($err) { + if($err instanceof JsonLdException) { + if($err->getCode()) { + return $err->getCode(); + } + if($err->cause) { + return $this->getJsonLdErrorCode($err->cause); + } + } + return $err->getMessage(); + } +} + +class JsonLdTestIterator implements Iterator { + /** + * The current test index. + */ + protected $index = 0; + + /** + * The total number of tests. + */ + protected $count = 0; + + /** + * Creates a TestIterator. + * + * @param string $type the type of tests to iterate over. + */ + public function __construct($type) { + global $TESTS; + if(isset($TESTS[$type])) { + $this->tests = $TESTS[$type]; + } else { + $this->tests = array(); + } + $this->count = count($this->tests); + } + + /** + * Gets the parameters for the next test. + * + * @return assoc the parameters for the next test. + */ + public function current() { + return array('test' => $this->tests[$this->index]); + } + + /** + * Gets the current test number. + * + * @return int the current test number. + */ + public function key() { + return $this->index; + } + + /** + * Proceeds to the next test. + */ + public function next() { + $this->index += 1; + } + + /** + * Rewinds to the first test. + */ + public function rewind() { + $this->index = 0; + } + + /** + * Returns true if there are more tests to be run. + * + * @return bool true if there are more tests to be run. + */ + public function valid() { + return $this->index < $this->count; + } +} + +class EarlReport extends PHPUnit_Util_Printer + implements PHPUnit_Framework_TestListener { + public function __construct() { + $this->filename = null; + $this->attached = false; + $this->report = (object)array( + '@context' => (object)array( + 'doap' => 'http://usefulinc.com/ns/doap#', + 'foaf' => 'http://xmlns.com/foaf/0.1/', + 'dc' => 'http://purl.org/dc/terms/', + 'earl' => 'http://www.w3.org/ns/earl#', + 'xsd' => 'http://www.w3.org/2001/XMLSchema#', + 'doap:homepage' => (object)array('@type' => '@id'), + 'doap:license' => (object)array('@type' => '@id'), + 'dc:creator' => (object)array('@type' => '@id'), + 'foaf:homepage' => (object)array('@type' => '@id'), + 'subjectOf' => (object)array('@reverse' => 'earl:subject'), + 'earl:assertedBy' => (object)array('@type' => '@id'), + 'earl:mode' => (object)array('@type' => '@id'), + 'earl:test' => (object)array('@type' => '@id'), + 'earl:outcome' => (object)array('@type' => '@id'), + 'dc:date' => (object)array('@type' => 'xsd:date') + ), + '@id' => 'https://github.com/digitalbazaar/php-json-ld', + '@type' => array('doap:Project', 'earl:TestSubject', 'earl:Software'), + 'doap:name' => 'php-json-ld', + 'dc:title' => 'php-json-ld', + 'doap:homepage' => 'https://github.com/digitalbazaar/php-json-ld', + 'doap:license' => 'https://github.com/digitalbazaar/php-json-ld/blob/master/LICENSE', + 'doap:description' => 'A JSON-LD processor for PHP', + 'doap:programming-language' => 'PHP', + 'dc:creator' => 'https://github.com/dlongley', + 'doap:developer' => (object)array( + '@id' => 'https://github.com/dlongley', + '@type' => array('foaf:Person', 'earl:Assertor'), + 'foaf:name' => 'Dave Longley', + 'foaf:homepage' => 'https://github.com/dlongley' + ), + 'dc:date' => array( + '@value' => gmdate('Y-m-d'), + '@type' => 'xsd:date' + ), + 'subjectOf' => array() + ); + } + + /** + * Attaches to the given test result, if not yet attached. + * + * @param PHPUnit_Framework_Test $result the result to attach to. + */ + public function attach(PHPUnit_Framework_TestResult $result) { + if(!$this->attached && $this->filename) { + $this->attached = true; + $result->addListener($this); + } + } + + /** + * Adds an assertion to this EARL report. + * + * @param JsonLdTest $test the JsonLdTest for the assertion is for. + * @param bool $passed whether or not the test passed. + */ + public function addAssertion($test, $passed) { + $this->report->{'subjectOf'}[] = (object)array( + '@type' => 'earl:Assertion', + 'earl:assertedBy' => $this->report->{'doap:developer'}->{'@id'}, + 'earl:mode' => 'earl:automatic', + 'earl:test' => $test->data->{'@id'}, + 'earl:result' => (object)array( + '@type' => 'earl:TestResult', + 'dc:date' => gmdate(DateTime::ISO8601), + 'earl:outcome' => $passed ? 'earl:passed' : 'earl:failed' + ) + ); + return $this; + } + + /** + * Writes this EARL report to a file. + */ + public function flush() { + if($this->filename) { + printf("\nWriting EARL report to: %s\n", $this->filename); + $fd = fopen($this->filename, 'w'); + fwrite($fd, Util::jsonldEncode($this->report)); + fclose($fd); + } + } + + public function endTest(PHPUnit_Framework_Test $test, $time) { + $this->addAssertion($test->test, true); + } + + public function addError( + PHPUnit_Framework_Test $test, Exception $e, $time) { + $this->addAssertion($test->test, false); + } + + public function addFailure( + PHPUnit_Framework_Test $test, + PHPUnit_Framework_AssertionFailedError $e, $time) { + $this->addAssertion($test->test, false); + if($test->result->shouldStop()) { + if(isset($test->test->name)) { + $name = $test->test->name; + } else if(isset($test->test->label)) { + $name = $test->test->label; + } else { + $name = 'UNNAMED'; + } + printf("\n\nFAILED\n"); + printf("Test: %s\n", $name); + printf("Purpose: %s\n", $test->test->data->purpose); + printf("EXPECTED: %s\n", Util::jsonldEncode($test->test->expected)); + printf("ACTUAL: %s\n", Util::jsonldEncode($test->test->actual)); + } + } + + public function addIncompleteTest( + PHPUnit_Framework_Test $test, Exception $e, $time) { + $this->addAssertion($test->test, false); + } + + public function addRiskyTest( + PHPUnit_Framework_Test $test, Exception $e, $time) {} + public function addSkippedTest( + PHPUnit_Framework_Test $test, Exception $e, $time) {} + public function startTest(PHPUnit_Framework_Test $test) {} + public function startTestSuite(PHPUnit_Framework_TestSuite $suite) {} + public function endTestSuite(PHPUnit_Framework_TestSuite $suite) {} +} + +class Util { + public static function readFile($filename) { + $rval = @file_get_contents($filename); + if($rval === false) { + throw new Exception('File read error: ' . $filename); + } + return $rval; + } + + public static function readJson($filename) { + $rval = json_decode(self::readFile($filename)); + if($rval === null) { + throw new Exception('JSON parse error'); + } + return $rval; + } + + public static function readNQuads($filename) { + return self::readFile($filename); + } + + public static function jsonldEncode($input) { + // newer PHP has a flag to avoid escaped '/' + if(defined('JSON_UNESCAPED_SLASHES')) { + $options = JSON_UNESCAPED_SLASHES; + if(defined('JSON_PRETTY_PRINT')) { + $options |= JSON_PRETTY_PRINT; + } + $json = json_encode($input, $options); + } else { + // use a simple string replacement of '\/' to '/'. + $json = str_replace('\\/', '/', json_encode($input)); + } + return $json; + } +} + +// tests to skip +$SKIP_TESTS = array(); + +// root manifest directory +$ROOT_MANIFEST_DIR; + +// parsed tests; keyed by type +$TESTS = array(); + +// parsed command line options +$OPTIONS = array(); + +// parse command line options +global $argv; +$args = $argv; +$total = count($args); +$start = false; +for($i = 0; $i < $total; ++$i) { + $arg = $args[$i]; + if(!$start) { + if(realpath($arg) === realpath(__FILE__)) { + $start = true; + } + continue; + } + if($arg[0] !== '-') { + break; + } + $i += 1; + $OPTIONS[$arg] = $args[$i]; +} +if(!isset($OPTIONS['-d'])) { + $dvar = 'path to json-ld.org/test-suite'; + $evar = 'file to write EARL report to'; + echo "php-json-ld Tests\n"; + echo "Usage: phpunit test.php -d <$dvar> [-e <$evar>]\n\n"; + exit(0); +} + +// EARL Report +$EARL = new EarlReport(); +if(isset($OPTIONS['-e'])) { + $EARL->filename = $OPTIONS['-e']; +} + +// load root manifest +$ROOT_MANIFEST_DIR = realpath($OPTIONS['-d']); +$filename = join( + DIRECTORY_SEPARATOR, array($ROOT_MANIFEST_DIR, 'manifest.jsonld')); +$root_manifest = Util::readJson($filename); +$manifest = new JsonLdManifest($root_manifest, $filename); +$manifest->load($TESTS); + +/* end of file, omit ?> */ -- cgit v1.2.3