initial sabre upgrade (needs lots of work - to wit: authentication, redo the browser interface, and rework event export/import)

1 files changed, 1627 insertions, 0 deletions

diff --git a/vendor/sabre/dav/lib/DAV/Server.php b/vendor/sabre/dav/lib/DAV/Server.php
new file mode 100644
index 000000000..b37652812
--- /dev/null
+++ b/vendor/sabre/dav/lib/DAV/Server.php
@@ -0,0 +1,1627 @@
+<?php
+
+namespace Sabre\DAV;
+
+use Sabre\Event\EventEmitter;
+use Sabre\HTTP;
+use Sabre\HTTP\RequestInterface;
+use Sabre\HTTP\ResponseInterface;
+use Sabre\HTTP\URLUtil;
+use Sabre\Uri;
+
+/**
+ * Main DAV server class
+ *
+ * @copyright Copyright (C) fruux GmbH (https://fruux.com/)
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Server extends EventEmitter {
+
+    /**
+     * Infinity is used for some request supporting the HTTP Depth header and indicates that the operation should traverse the entire tree
+     */
+    const DEPTH_INFINITY = -1;
+
+    /**
+     * XML namespace for all SabreDAV related elements
+     */
+    const NS_SABREDAV = 'http://sabredav.org/ns';
+
+    /**
+     * The tree object
+     *
+     * @var Sabre\DAV\Tree
+     */
+    public $tree;
+
+    /**
+     * The base uri
+     *
+     * @var string
+     */
+    protected $baseUri = null;
+
+    /**
+     * httpResponse
+     *
+     * @var Sabre\HTTP\Response
+     */
+    public $httpResponse;
+
+    /**
+     * httpRequest
+     *
+     * @var Sabre\HTTP\Request
+     */
+    public $httpRequest;
+
+    /**
+     * PHP HTTP Sapi
+     *
+     * @var Sabre\HTTP\Sapi
+     */
+    public $sapi;
+
+    /**
+     * The list of plugins
+     *
+     * @var array
+     */
+    protected $plugins = [];
+
+    /**
+     * This property will be filled with a unique string that describes the
+     * transaction. This is useful for performance measuring and logging
+     * purposes.
+     *
+     * By default it will just fill it with a lowercased HTTP method name, but
+     * plugins override this. For example, the WebDAV-Sync sync-collection
+     * report will set this to 'report-sync-collection'.
+     *
+     * @var string
+     */
+    public $transactionType;
+
+    /**
+     * This is a list of properties that are always server-controlled, and
+     * must not get modified with PROPPATCH.
+     *
+     * Plugins may add to this list.
+     *
+     * @var string[]
+     */
+    public $protectedProperties = [
+
+        // RFC4918
+        '{DAV:}getcontentlength',
+        '{DAV:}getetag',
+        '{DAV:}getlastmodified',
+        '{DAV:}lockdiscovery',
+        '{DAV:}supportedlock',
+
+        // RFC4331
+        '{DAV:}quota-available-bytes',
+        '{DAV:}quota-used-bytes',
+
+        // RFC3744
+        '{DAV:}supported-privilege-set',
+        '{DAV:}current-user-privilege-set',
+        '{DAV:}acl',
+        '{DAV:}acl-restrictions',
+        '{DAV:}inherited-acl-set',
+
+        // RFC3253
+        '{DAV:}supported-method-set',
+        '{DAV:}supported-report-set',
+
+        // RFC6578
+        '{DAV:}sync-token',
+
+        // calendarserver.org extensions
+        '{http://calendarserver.org/ns/}ctag',
+
+        // sabredav extensions
+        '{http://sabredav.org/ns}sync-token',
+
+    ];
+
+    /**
+     * This is a flag that allow or not showing file, line and code
+     * of the exception in the returned XML
+     *
+     * @var bool
+     */
+    public $debugExceptions = false;
+
+    /**
+     * This property allows you to automatically add the 'resourcetype' value
+     * based on a node's classname or interface.
+     *
+     * The preset ensures that {DAV:}collection is automatically added for nodes
+     * implementing Sabre\DAV\ICollection.
+     *
+     * @var array
+     */
+    public $resourceTypeMapping = [
+        'Sabre\\DAV\\ICollection' => '{DAV:}collection',
+    ];
+
+    /**
+     * This property allows the usage of Depth: infinity on PROPFIND requests.
+     *
+     * By default Depth: infinity is treated as Depth: 1. Allowing Depth:
+     * infinity is potentially risky, as it allows a single client to do a full
+     * index of the webdav server, which is an easy DoS attack vector.
+     *
+     * Only turn this on if you know what you're doing.
+     *
+     * @var bool
+     */
+    public $enablePropfindDepthInfinity = false;
+
+    /**
+     * Reference to the XML utility object.
+     *
+     * @var Xml\Service
+     */
+    public $xml;
+
+    /**
+     * If this setting is turned off, SabreDAV's version number will be hidden
+     * from various places.
+     *
+     * Some people feel this is a good security measure.
+     *
+     * @var bool
+     */
+    static $exposeVersion = true;
+
+    /**
+     * Sets up the server
+     *
+     * If a Sabre\DAV\Tree object is passed as an argument, it will
+     * use it as the directory tree. If a Sabre\DAV\INode is passed, it
+     * will create a Sabre\DAV\Tree and use the node as the root.
+     *
+     * If nothing is passed, a Sabre\DAV\SimpleCollection is created in
+     * a Sabre\DAV\Tree.
+     *
+     * If an array is passed, we automatically create a root node, and use
+     * the nodes in the array as top-level children.
+     *
+     * @param Tree|INode|array|null $treeOrNode The tree object
+     */
+    function __construct($treeOrNode = null) {
+
+        if ($treeOrNode instanceof Tree) {
+            $this->tree = $treeOrNode;
+        } elseif ($treeOrNode instanceof INode) {
+            $this->tree = new Tree($treeOrNode);
+        } elseif (is_array($treeOrNode)) {
+
+            // If it's an array, a list of nodes was passed, and we need to
+            // create the root node.
+            foreach ($treeOrNode as $node) {
+                if (!($node instanceof INode)) {
+                    throw new Exception('Invalid argument passed to constructor. If you\'re passing an array, all the values must implement Sabre\\DAV\\INode');
+                }
+            }
+
+            $root = new SimpleCollection('root', $treeOrNode);
+            $this->tree = new Tree($root);
+
+        } elseif (is_null($treeOrNode)) {
+            $root = new SimpleCollection('root');
+            $this->tree = new Tree($root);
+        } else {
+            throw new Exception('Invalid argument passed to constructor. Argument must either be an instance of Sabre\\DAV\\Tree, Sabre\\DAV\\INode, an array or null');
+        }
+
+        $this->xml = new Xml\Service();
+        $this->sapi = new HTTP\Sapi();
+        $this->httpResponse = new HTTP\Response();
+        $this->httpRequest = $this->sapi->getRequest();
+        $this->addPlugin(new CorePlugin());
+
+    }
+
+    /**
+     * Starts the DAV Server
+     *
+     * @return void
+     */
+    function exec() {
+
+        try {
+
+            // If nginx (pre-1.2) is used as a proxy server, and SabreDAV as an
+            // origin, we must make sure we send back HTTP/1.0 if this was
+            // requested.
+            // This is mainly because nginx doesn't support Chunked Transfer
+            // Encoding, and this forces the webserver SabreDAV is running on,
+            // to buffer entire responses to calculate Content-Length.
+            $this->httpResponse->setHTTPVersion($this->httpRequest->getHTTPVersion());
+
+            // Setting the base url
+            $this->httpRequest->setBaseUrl($this->getBaseUri());
+            $this->invokeMethod($this->httpRequest, $this->httpResponse);
+
+        } catch (\Exception $e) {
+
+            try {
+                $this->emit('exception', [$e]);
+            } catch (\Exception $ignore) {
+            }
+            $DOM = new \DOMDocument('1.0', 'utf-8');
+            $DOM->formatOutput = true;
+
+            $error = $DOM->createElementNS('DAV:', 'd:error');
+            $error->setAttribute('xmlns:s', self::NS_SABREDAV);
+            $DOM->appendChild($error);
+
+            $h = function($v) {
+
+                return htmlspecialchars($v, ENT_NOQUOTES, 'UTF-8');
+
+            };
+
+            if (self::$exposeVersion) {
+                $error->appendChild($DOM->createElement('s:sabredav-version', $h(Version::VERSION)));
+            }
+
+            $error->appendChild($DOM->createElement('s:exception', $h(get_class($e))));
+            $error->appendChild($DOM->createElement('s:message', $h($e->getMessage())));
+            if ($this->debugExceptions) {
+                $error->appendChild($DOM->createElement('s:file', $h($e->getFile())));
+                $error->appendChild($DOM->createElement('s:line', $h($e->getLine())));
+                $error->appendChild($DOM->createElement('s:code', $h($e->getCode())));
+                $error->appendChild($DOM->createElement('s:stacktrace', $h($e->getTraceAsString())));
+            }
+
+            if ($this->debugExceptions) {
+                $previous = $e;
+                while ($previous = $previous->getPrevious()) {
+                    $xPrevious = $DOM->createElement('s:previous-exception');
+                    $xPrevious->appendChild($DOM->createElement('s:exception', $h(get_class($previous))));
+                    $xPrevious->appendChild($DOM->createElement('s:message', $h($previous->getMessage())));
+                    $xPrevious->appendChild($DOM->createElement('s:file', $h($previous->getFile())));
+                    $xPrevious->appendChild($DOM->createElement('s:line', $h($previous->getLine())));
+                    $xPrevious->appendChild($DOM->createElement('s:code', $h($previous->getCode())));
+                    $xPrevious->appendChild($DOM->createElement('s:stacktrace', $h($previous->getTraceAsString())));
+                    $error->appendChild($xPrevious);
+                }
+            }
+
+
+            if ($e instanceof Exception) {
+
+                $httpCode = $e->getHTTPCode();
+                $e->serialize($this, $error);
+                $headers = $e->getHTTPHeaders($this);
+
+            } else {
+
+                $httpCode = 500;
+                $headers = [];
+
+            }
+            $headers['Content-Type'] = 'application/xml; charset=utf-8';
+
+            $this->httpResponse->setStatus($httpCode);
+            $this->httpResponse->setHeaders($headers);
+            $this->httpResponse->setBody($DOM->saveXML());
+            $this->sapi->sendResponse($this->httpResponse);
+
+        }
+
+    }
+
+    /**
+     * Sets the base server uri
+     *
+     * @param string $uri
+     * @return void
+     */
+    function setBaseUri($uri) {
+
+        // If the baseUri does not end with a slash, we must add it
+        if ($uri[strlen($uri) - 1] !== '/')
+            $uri .= '/';
+
+        $this->baseUri = $uri;
+
+    }
+
+    /**
+     * Returns the base responding uri
+     *
+     * @return string
+     */
+    function getBaseUri() {
+
+        if (is_null($this->baseUri)) $this->baseUri = $this->guessBaseUri();
+        return $this->baseUri;
+
+    }
+
+    /**
+     * This method attempts to detect the base uri.
+     * Only the PATH_INFO variable is considered.
+     *
+     * If this variable is not set, the root (/) is assumed.
+     *
+     * @return string
+     */
+    function guessBaseUri() {
+
+        $pathInfo = $this->httpRequest->getRawServerValue('PATH_INFO');
+        $uri = $this->httpRequest->getRawServerValue('REQUEST_URI');
+
+        // If PATH_INFO is found, we can assume it's accurate.
+        if (!empty($pathInfo)) {
+
+            // We need to make sure we ignore the QUERY_STRING part
+            if ($pos = strpos($uri, '?'))
+                $uri = substr($uri, 0, $pos);
+
+            // PATH_INFO is only set for urls, such as: /example.php/path
+            // in that case PATH_INFO contains '/path'.
+            // Note that REQUEST_URI is percent encoded, while PATH_INFO is
+            // not, Therefore they are only comparable if we first decode
+            // REQUEST_INFO as well.
+            $decodedUri = URLUtil::decodePath($uri);
+
+            // A simple sanity check:
+            if (substr($decodedUri, strlen($decodedUri) - strlen($pathInfo)) === $pathInfo) {
+                $baseUri = substr($decodedUri, 0, strlen($decodedUri) - strlen($pathInfo));
+                return rtrim($baseUri, '/') . '/';
+            }
+
+            throw new Exception('The REQUEST_URI (' . $uri . ') did not end with the contents of PATH_INFO (' . $pathInfo . '). This server might be misconfigured.');
+
+        }
+
+        // The last fallback is that we're just going to assume the server root.
+        return '/';
+
+    }
+
+    /**
+     * Adds a plugin to the server
+     *
+     * For more information, console the documentation of Sabre\DAV\ServerPlugin
+     *
+     * @param ServerPlugin $plugin
+     * @return void
+     */
+    function addPlugin(ServerPlugin $plugin) {
+
+        $this->plugins[$plugin->getPluginName()] = $plugin;
+        $plugin->initialize($this);
+
+    }
+
+    /**
+     * Returns an initialized plugin by it's name.
+     *
+     * This function returns null if the plugin was not found.
+     *
+     * @param string $name
+     * @return ServerPlugin
+     */
+    function getPlugin($name) {
+
+        if (isset($this->plugins[$name]))
+            return $this->plugins[$name];
+
+        return null;
+
+    }
+
+    /**
+     * Returns all plugins
+     *
+     * @return array
+     */
+    function getPlugins() {
+
+        return $this->plugins;
+
+    }
+
+    /**
+     * Handles a http request, and execute a method based on its name
+     *
+     * @param RequestInterface $request
+     * @param ResponseInterface $response
+     * @param $sendResponse Whether to send the HTTP response to the DAV client.
+     * @return void
+     */
+    function invokeMethod(RequestInterface $request, ResponseInterface $response, $sendResponse = true) {
+
+        $method = $request->getMethod();
+
+        if (!$this->emit('beforeMethod:' . $method, [$request, $response])) return;
+        if (!$this->emit('beforeMethod', [$request, $response])) return;
+
+        if (self::$exposeVersion) {
+            $response->setHeader('X-Sabre-Version', Version::VERSION);
+        }
+
+        $this->transactionType = strtolower($method);
+
+        if (!$this->checkPreconditions($request, $response)) {
+            $this->sapi->sendResponse($response);
+            return;
+        }
+
+        if ($this->emit('method:' . $method, [$request, $response])) {
+            if ($this->emit('method', [$request, $response])) {
+                $exMessage = "There was no plugin in the system that was willing to handle this " . $method . " method.";
+                if ($method === "GET") {
+                    $exMessage .= " Enable the Browser plugin to get a better result here.";
+                }
+
+                // Unsupported method
+                throw new Exception\NotImplemented($exMessage);
+            }
+        }
+
+        if (!$this->emit('afterMethod:' . $method, [$request, $response])) return;
+        if (!$this->emit('afterMethod', [$request, $response])) return;
+
+        if ($response->getStatus() === null) {
+            throw new Exception('No subsystem set a valid HTTP status code. Something must have interrupted the request without providing further detail.');
+        }
+        if ($sendResponse) {
+            $this->sapi->sendResponse($response);
+            $this->emit('afterResponse', [$request, $response]);
+        }
+
+    }
+
+    // {{{ HTTP/WebDAV protocol helpers
+
+    /**
+     * Returns an array with all the supported HTTP methods for a specific uri.
+     *
+     * @param string $path
+     * @return array
+     */
+    function getAllowedMethods($path) {
+
+        $methods = [
+            'OPTIONS',
+            'GET',
+            'HEAD',
+            'DELETE',
+            'PROPFIND',
+            'PUT',
+            'PROPPATCH',
+            'COPY',
+            'MOVE',
+            'REPORT'
+        ];
+
+        // The MKCOL is only allowed on an unmapped uri
+        try {
+            $this->tree->getNodeForPath($path);
+        } catch (Exception\NotFound $e) {
+            $methods[] = 'MKCOL';
+        }
+
+        // We're also checking if any of the plugins register any new methods
+        foreach ($this->plugins as $plugin) $methods = array_merge($methods, $plugin->getHTTPMethods($path));
+        array_unique($methods);
+
+        return $methods;
+
+    }
+
+    /**
+     * Gets the uri for the request, keeping the base uri into consideration
+     *
+     * @return string
+     */
+    function getRequestUri() {
+
+        return $this->calculateUri($this->httpRequest->getUrl());
+
+    }
+
+    /**
+     * Turns a URI such as the REQUEST_URI into a local path.
+     *
+     * This method:
+     *   * strips off the base path
+     *   * normalizes the path
+     *   * uri-decodes the path
+     *
+     * @param string $uri
+     * @throws Exception\Forbidden A permission denied exception is thrown whenever there was an attempt to supply a uri outside of the base uri
+     * @return string
+     */
+    function calculateUri($uri) {
+
+        if ($uri[0] != '/' && strpos($uri, '://')) {
+
+            $uri = parse_url($uri, PHP_URL_PATH);
+
+        }
+
+        $uri = Uri\normalize(str_replace('//', '/', $uri));
+        $baseUri = Uri\normalize($this->getBaseUri());
+
+        if (strpos($uri, $baseUri) === 0) {
+
+            return trim(URLUtil::decodePath(substr($uri, strlen($baseUri))), '/');
+
+        // A special case, if the baseUri was accessed without a trailing
+        // slash, we'll accept it as well.
+        } elseif ($uri . '/' === $baseUri) {
+
+            return '';
+
+        } else {
+
+            throw new Exception\Forbidden('Requested uri (' . $uri . ') is out of base uri (' . $this->getBaseUri() . ')');
+
+        }
+
+    }
+
+    /**
+     * Returns the HTTP depth header
+     *
+     * This method returns the contents of the HTTP depth request header. If the depth header was 'infinity' it will return the Sabre\DAV\Server::DEPTH_INFINITY object
+     * It is possible to supply a default depth value, which is used when the depth header has invalid content, or is completely non-existent
+     *
+     * @param mixed $default
+     * @return int
+     */
+    function getHTTPDepth($default = self::DEPTH_INFINITY) {
+
+        // If its not set, we'll grab the default
+        $depth = $this->httpRequest->getHeader('Depth');
+
+        if (is_null($depth)) return $default;
+
+        if ($depth == 'infinity') return self::DEPTH_INFINITY;
+
+
+        // If its an unknown value. we'll grab the default
+        if (!ctype_digit($depth)) return $default;
+
+        return (int)$depth;
+
+    }
+
+    /**
+     * Returns the HTTP range header
+     *
+     * This method returns null if there is no well-formed HTTP range request
+     * header or array($start, $end).
+     *
+     * The first number is the offset of the first byte in the range.
+     * The second number is the offset of the last byte in the range.
+     *
+     * If the second offset is null, it should be treated as the offset of the last byte of the entity
+     * If the first offset is null, the second offset should be used to retrieve the last x bytes of the entity
+     *
+     * @return array|null
+     */
+    function getHTTPRange() {
+
+        $range = $this->httpRequest->getHeader('range');
+        if (is_null($range)) return null;
+
+        // Matching "Range: bytes=1234-5678: both numbers are optional
+
+        if (!preg_match('/^bytes=([0-9]*)-([0-9]*)$/i', $range, $matches)) return null;
+
+        if ($matches[1] === '' && $matches[2] === '') return null;
+
+        return [
+            $matches[1] !== '' ? $matches[1] : null,
+            $matches[2] !== '' ? $matches[2] : null,
+        ];
+
+    }
+
+    /**
+     * Returns the HTTP Prefer header information.
+     *
+     * The prefer header is defined in:
+     * http://tools.ietf.org/html/draft-snell-http-prefer-14
+     *
+     * This method will return an array with options.
+     *
+     * Currently, the following options may be returned:
+     *  [
+     *      'return-asynch'         => true,
+     *      'return-minimal'        => true,
+     *      'return-representation' => true,
+     *      'wait'                  => 30,
+     *      'strict'                => true,
+     *      'lenient'               => true,
+     *  ]
+     *
+     * This method also supports the Brief header, and will also return
+     * 'return-minimal' if the brief header was set to 't'.
+     *
+     * For the boolean options, false will be returned if the headers are not
+     * specified. For the integer options it will be 'null'.
+     *
+     * @return array
+     */
+    function getHTTPPrefer() {
+
+        $result = [
+            // can be true or false
+            'respond-async' => false,
+            // Could be set to 'representation' or 'minimal'.
+            'return'        => null,
+            // Used as a timeout, is usually a number.
+            'wait'          => null,
+            // can be 'strict' or 'lenient'.
+            'handling'      => false,
+        ];
+
+        if ($prefer = $this->httpRequest->getHeader('Prefer')) {
+
+            $result = array_merge(
+                $result,
+                \Sabre\HTTP\parsePrefer($prefer)
+            );
+
+        } elseif ($this->httpRequest->getHeader('Brief') == 't') {
+            $result['return'] = 'minimal';
+        }
+
+        return $result;
+
+    }
+
+
+    /**
+     * Returns information about Copy and Move requests
+     *
+     * This function is created to help getting information about the source and the destination for the
+     * WebDAV MOVE and COPY HTTP request. It also validates a lot of information and throws proper exceptions
+     *
+     * The returned value is an array with the following keys:
+     *   * destination - Destination path
+     *   * destinationExists - Whether or not the destination is an existing url (and should therefore be overwritten)
+     *
+     * @param RequestInterface $request
+     * @throws Exception\BadRequest upon missing or broken request headers
+     * @throws Exception\UnsupportedMediaType when trying to copy into a
+     *         non-collection.
+     * @throws Exception\PreconditionFailed If overwrite is set to false, but
+     *         the destination exists.
+     * @throws Exception\Forbidden when source and destination paths are
+     *         identical.
+     * @throws Exception\Conflict When trying to copy a node into its own
+     *         subtree.
+     * @return array
+     */
+    function getCopyAndMoveInfo(RequestInterface $request) {
+
+        // Collecting the relevant HTTP headers
+        if (!$request->getHeader('Destination')) throw new Exception\BadRequest('The destination header was not supplied');
+        $destination = $this->calculateUri($request->getHeader('Destination'));
+        $overwrite = $request->getHeader('Overwrite');
+        if (!$overwrite) $overwrite = 'T';
+        if (strtoupper($overwrite) == 'T') $overwrite = true;
+        elseif (strtoupper($overwrite) == 'F') $overwrite = false;
+        // We need to throw a bad request exception, if the header was invalid
+        else throw new Exception\BadRequest('The HTTP Overwrite header should be either T or F');
+
+        list($destinationDir) = URLUtil::splitPath($destination);
+
+        try {
+            $destinationParent = $this->tree->getNodeForPath($destinationDir);
+            if (!($destinationParent instanceof ICollection)) throw new Exception\UnsupportedMediaType('The destination node is not a collection');
+        } catch (Exception\NotFound $e) {
+
+            // If the destination parent node is not found, we throw a 409
+            throw new Exception\Conflict('The destination node is not found');
+        }
+
+        try {
+
+            $destinationNode = $this->tree->getNodeForPath($destination);
+
+            // If this succeeded, it means the destination already exists
+            // we'll need to throw precondition failed in case overwrite is false
+            if (!$overwrite) throw new Exception\PreconditionFailed('The destination node already exists, and the overwrite header is set to false', 'Overwrite');
+
+        } catch (Exception\NotFound $e) {
+
+            // Destination didn't exist, we're all good
+            $destinationNode = false;
+
+        }
+
+        $requestPath = $request->getPath();
+        if ($destination === $requestPath) {
+            throw new Exception\Forbidden('Source and destination uri are identical.');
+        }
+        if (substr($destination, 0, strlen($requestPath) + 1) === $requestPath . '/') {
+            throw new Exception\Conflict('The destination may not be part of the same subtree as the source path.');
+        }
+
+        // These are the three relevant properties we need to return
+        return [
+            'destination'       => $destination,
+            'destinationExists' => !!$destinationNode,
+            'destinationNode'   => $destinationNode,
+        ];
+
+    }
+
+    /**
+     * Returns a list of properties for a path
+     *
+     * This is a simplified version getPropertiesForPath. If you aren't
+     * interested in status codes, but you just want to have a flat list of
+     * properties, use this method.
+     *
+     * Please note though that any problems related to retrieving properties,
+     * such as permission issues will just result in an empty array being
+     * returned.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     */
+    function getProperties($path, $propertyNames) {
+
+        $result = $this->getPropertiesForPath($path, $propertyNames, 0);
+        if (isset($result[0][200])) {
+            return $result[0][200];
+        } else {
+            return [];
+        }
+
+    }
+
+    /**
+     * A kid-friendly way to fetch properties for a node's children.
+     *
+     * The returned array will be indexed by the path of the of child node.
+     * Only properties that are actually found will be returned.
+     *
+     * The parent node will not be returned.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     * @return array
+     */
+    function getPropertiesForChildren($path, $propertyNames) {
+
+        $result = [];
+        foreach ($this->getPropertiesForPath($path, $propertyNames, 1) as $k => $row) {
+
+            // Skipping the parent path
+            if ($k === 0) continue;
+
+            $result[$row['href']] = $row[200];
+
+        }
+        return $result;
+
+    }
+
+    /**
+     * Returns a list of HTTP headers for a particular resource
+     *
+     * The generated http headers are based on properties provided by the
+     * resource. The method basically provides a simple mapping between
+     * DAV property and HTTP header.
+     *
+     * The headers are intended to be used for HEAD and GET requests.
+     *
+     * @param string $path
+     * @return array
+     */
+    function getHTTPHeaders($path) {
+
+        $propertyMap = [
+            '{DAV:}getcontenttype'   => 'Content-Type',
+            '{DAV:}getcontentlength' => 'Content-Length',
+            '{DAV:}getlastmodified'  => 'Last-Modified',
+            '{DAV:}getetag'          => 'ETag',
+        ];
+
+        $properties = $this->getProperties($path, array_keys($propertyMap));
+
+        $headers = [];
+        foreach ($propertyMap as $property => $header) {
+            if (!isset($properties[$property])) continue;
+
+            if (is_scalar($properties[$property])) {
+                $headers[$header] = $properties[$property];
+
+            // GetLastModified gets special cased
+            } elseif ($properties[$property] instanceof Xml\Property\GetLastModified) {
+                $headers[$header] = HTTP\Util::toHTTPDate($properties[$property]->getTime());
+            }
+
+        }
+
+        return $headers;
+
+    }
+
+    /**
+     * Small helper to support PROPFIND with DEPTH_INFINITY.
+     *
+     * @param array[] $propFindRequests
+     * @param PropFind $propFind
+     * @return void
+     */
+    private function addPathNodesRecursively(&$propFindRequests, PropFind $propFind) {
+
+        $newDepth = $propFind->getDepth();
+        $path = $propFind->getPath();
+
+        if ($newDepth !== self::DEPTH_INFINITY) {
+            $newDepth--;
+        }
+
+        foreach ($this->tree->getChildren($path) as $childNode) {
+            $subPropFind = clone $propFind;
+            $subPropFind->setDepth($newDepth);
+            if ($path !== '') {
+                $subPath = $path . '/' . $childNode->getName();
+            } else {
+                $subPath = $childNode->getName();
+            }
+            $subPropFind->setPath($subPath);
+
+            $propFindRequests[] = [
+                $subPropFind,
+                $childNode
+            ];
+
+            if (($newDepth === self::DEPTH_INFINITY || $newDepth >= 1) && $childNode instanceof ICollection) {
+                $this->addPathNodesRecursively($propFindRequests, $subPropFind);
+            }
+
+        }
+    }
+
+    /**
+     * Returns a list of properties for a given path
+     *
+     * The path that should be supplied should have the baseUrl stripped out
+     * The list of properties should be supplied in Clark notation. If the list is empty
+     * 'allprops' is assumed.
+     *
+     * If a depth of 1 is requested child elements will also be returned.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     * @param int $depth
+     * @return array
+     */
+    function getPropertiesForPath($path, $propertyNames = [], $depth = 0) {
+
+        // The only two options for the depth of a propfind is 0 or 1 - as long as depth infinity is not enabled
+        if (!$this->enablePropfindDepthInfinity && $depth != 0) $depth = 1;
+
+        $path = trim($path, '/');
+
+        $propFindType = $propertyNames ? PropFind::NORMAL : PropFind::ALLPROPS;
+        $propFind = new PropFind($path, (array)$propertyNames, $depth, $propFindType);
+
+        $parentNode = $this->tree->getNodeForPath($path);
+
+        $propFindRequests = [[
+            $propFind,
+            $parentNode
+        ]];
+
+        if (($depth > 0 || $depth === self::DEPTH_INFINITY) && $parentNode instanceof ICollection) {
+            $this->addPathNodesRecursively($propFindRequests, $propFind);
+        }
+
+        $returnPropertyList = [];
+
+        foreach ($propFindRequests as $propFindRequest) {
+
+            list($propFind, $node) = $propFindRequest;
+            $r = $this->getPropertiesByNode($propFind, $node);
+            if ($r) {
+                $result = $propFind->getResultForMultiStatus();
+                $result['href'] = $propFind->getPath();
+
+                // WebDAV recommends adding a slash to the path, if the path is
+                // a collection.
+                // Furthermore, iCal also demands this to be the case for
+                // principals. This is non-standard, but we support it.
+                $resourceType = $this->getResourceTypeForNode($node);
+                if (in_array('{DAV:}collection', $resourceType) || in_array('{DAV:}principal', $resourceType)) {
+                    $result['href'] .= '/';
+                }
+                $returnPropertyList[] = $result;
+            }
+
+        }
+
+        return $returnPropertyList;
+
+    }
+
+    /**
+     * Returns a list of properties for a list of paths.
+     *
+     * The path that should be supplied should have the baseUrl stripped out
+     * The list of properties should be supplied in Clark notation. If the list is empty
+     * 'allprops' is assumed.
+     *
+     * The result is returned as an array, with paths for it's keys.
+     * The result may be returned out of order.
+     *
+     * @param array $paths
+     * @param array $propertyNames
+     * @return array
+     */
+    function getPropertiesForMultiplePaths(array $paths, array $propertyNames = []) {
+
+        $result = [
+        ];
+
+        $nodes = $this->tree->getMultipleNodes($paths);
+
+        foreach ($nodes as $path => $node) {
+
+            $propFind = new PropFind($path, $propertyNames);
+            $r = $this->getPropertiesByNode($propFind, $node);
+            if ($r) {
+                $result[$path] = $propFind->getResultForMultiStatus();
+                $result[$path]['href'] = $path;
+
+                $resourceType = $this->getResourceTypeForNode($node);
+                if (in_array('{DAV:}collection', $resourceType) || in_array('{DAV:}principal', $resourceType)) {
+                    $result[$path]['href'] .= '/';
+                }
+            }
+
+        }
+
+        return $result;
+
+    }
+
+
+    /**
+     * Determines all properties for a node.
+     *
+     * This method tries to grab all properties for a node. This method is used
+     * internally getPropertiesForPath and a few others.
+     *
+     * It could be useful to call this, if you already have an instance of your
+     * target node and simply want to run through the system to get a correct
+     * list of properties.
+     *
+     * @param PropFind $propFind
+     * @param INode $node
+     * @return bool
+     */
+    function getPropertiesByNode(PropFind $propFind, INode $node) {
+
+        return $this->emit('propFind', [$propFind, $node]);
+
+    }
+
+    /**
+     * This method is invoked by sub-systems creating a new file.
+     *
+     * Currently this is done by HTTP PUT and HTTP LOCK (in the Locks_Plugin).
+     * It was important to get this done through a centralized function,
+     * allowing plugins to intercept this using the beforeCreateFile event.
+     *
+     * This method will return true if the file was actually created
+     *
+     * @param string   $uri
+     * @param resource $data
+     * @param string   $etag
+     * @return bool
+     */
+    function createFile($uri, $data, &$etag = null) {
+
+        list($dir, $name) = URLUtil::splitPath($uri);
+
+        if (!$this->emit('beforeBind', [$uri])) return false;
+
+        $parent = $this->tree->getNodeForPath($dir);
+        if (!$parent instanceof ICollection) {
+            throw new Exception\Conflict('Files can only be created as children of collections');
+        }
+
+        // It is possible for an event handler to modify the content of the
+        // body, before it gets written. If this is the case, $modified
+        // should be set to true.
+        //
+        // If $modified is true, we must not send back an ETag.
+        $modified = false;
+        if (!$this->emit('beforeCreateFile', [$uri, &$data, $parent, &$modified])) return false;
+
+        $etag = $parent->createFile($name, $data);
+
+        if ($modified) $etag = null;
+
+        $this->tree->markDirty($dir . '/' . $name);
+
+        $this->emit('afterBind', [$uri]);
+        $this->emit('afterCreateFile', [$uri, $parent]);
+
+        return true;
+    }
+
+    /**
+     * This method is invoked by sub-systems updating a file.
+     *
+     * This method will return true if the file was actually updated
+     *
+     * @param string   $uri
+     * @param resource $data
+     * @param string   $etag
+     * @return bool
+     */
+    function updateFile($uri, $data, &$etag = null) {
+
+        $node = $this->tree->getNodeForPath($uri);
+
+        // It is possible for an event handler to modify the content of the
+        // body, before it gets written. If this is the case, $modified
+        // should be set to true.
+        //
+        // If $modified is true, we must not send back an ETag.
+        $modified = false;
+        if (!$this->emit('beforeWriteContent', [$uri, $node, &$data, &$modified])) return false;
+
+        $etag = $node->put($data);
+        if ($modified) $etag = null;
+        $this->emit('afterWriteContent', [$uri, $node]);
+
+        return true;
+    }
+
+
+
+    /**
+     * This method is invoked by sub-systems creating a new directory.
+     *
+     * @param string $uri
+     * @return void
+     */
+    function createDirectory($uri) {
+
+        $this->createCollection($uri, new MkCol(['{DAV:}collection'], []));
+
+    }
+
+    /**
+     * Use this method to create a new collection
+     *
+     * @param string $uri The new uri
+     * @param MkCol $mkCol
+     * @return array|null
+     */
+    function createCollection($uri, MkCol $mkCol) {
+
+        list($parentUri, $newName) = URLUtil::splitPath($uri);
+
+        // Making sure the parent exists
+        try {
+            $parent = $this->tree->getNodeForPath($parentUri);
+
+        } catch (Exception\NotFound $e) {
+            throw new Exception\Conflict('Parent node does not exist');
+
+        }
+
+        // Making sure the parent is a collection
+        if (!$parent instanceof ICollection) {
+            throw new Exception\Conflict('Parent node is not a collection');
+        }
+
+        // Making sure the child does not already exist
+        try {
+            $parent->getChild($newName);
+
+            // If we got here.. it means there's already a node on that url, and we need to throw a 405
+            throw new Exception\MethodNotAllowed('The resource you tried to create already exists');
+
+        } catch (Exception\NotFound $e) {
+            // NotFound is the expected behavior.
+        }
+
+
+        if (!$this->emit('beforeBind', [$uri])) return;
+
+        if ($parent instanceof IExtendedCollection) {
+
+            /**
+             * If the parent is an instance of IExtendedCollection, it means that
+             * we can pass the MkCol object directly as it may be able to store
+             * properties immediately.
+             */
+            $parent->createExtendedCollection($newName, $mkCol);
+
+        } else {
+
+            /**
+             * If the parent is a standard ICollection, it means only
+             * 'standard' collections can be created, so we should fail any
+             * MKCOL operation that carries extra resourcetypes.
+             */
+            if (count($mkCol->getResourceType()) > 1) {
+                throw new Exception\InvalidResourceType('The {DAV:}resourcetype you specified is not supported here.');
+            }
+
+            $parent->createDirectory($newName);
+
+        }
+
+        // If there are any properties that have not been handled/stored,
+        // we ask the 'propPatch' event to handle them. This will allow for
+        // example the propertyStorage system to store properties upon MKCOL.
+        if ($mkCol->getRemainingMutations()) {
+            $this->emit('propPatch', [$uri, $mkCol]);
+        }
+        $success = $mkCol->commit();
+
+        if (!$success) {
+            $result = $mkCol->getResult();
+            // generateMkCol needs the href key to exist.
+            $result['href'] = $uri;
+            return $result;
+        }
+
+        $this->tree->markDirty($parentUri);
+        $this->emit('afterBind', [$uri]);
+
+    }
+
+    /**
+     * This method updates a resource's properties
+     *
+     * The properties array must be a list of properties. Array-keys are
+     * property names in clarknotation, array-values are it's values.
+     * If a property must be deleted, the value should be null.
+     *
+     * Note that this request should either completely succeed, or
+     * completely fail.
+     *
+     * The response is an array with properties for keys, and http status codes
+     * as their values.
+     *
+     * @param string $path
+     * @param array $properties
+     * @return array
+     */
+    function updateProperties($path, array $properties) {
+
+        $propPatch = new PropPatch($properties);
+        $this->emit('propPatch', [$path, $propPatch]);
+        $propPatch->commit();
+
+        return $propPatch->getResult();
+
+    }
+
+    /**
+     * This method checks the main HTTP preconditions.
+     *
+     * Currently these are:
+     *   * If-Match
+     *   * If-None-Match
+     *   * If-Modified-Since
+     *   * If-Unmodified-Since
+     *
+     * The method will return true if all preconditions are met
+     * The method will return false, or throw an exception if preconditions
+     * failed. If false is returned the operation should be aborted, and
+     * the appropriate HTTP response headers are already set.
+     *
+     * Normally this method will throw 412 Precondition Failed for failures
+     * related to If-None-Match, If-Match and If-Unmodified Since. It will
+     * set the status to 304 Not Modified for If-Modified_since.
+     *
+     * @param RequestInterface $request
+     * @param ResponseInterface $response
+     * @return bool
+     */
+    function checkPreconditions(RequestInterface $request, ResponseInterface $response) {
+
+        $path = $request->getPath();
+        $node = null;
+        $lastMod = null;
+        $etag = null;
+
+        if ($ifMatch = $request->getHeader('If-Match')) {
+
+            // If-Match contains an entity tag. Only if the entity-tag
+            // matches we are allowed to make the request succeed.
+            // If the entity-tag is '*' we are only allowed to make the
+            // request succeed if a resource exists at that url.
+            try {
+                $node = $this->tree->getNodeForPath($path);
+            } catch (Exception\NotFound $e) {
+                throw new Exception\PreconditionFailed('An If-Match header was specified and the resource did not exist', 'If-Match');
+            }
+
+            // Only need to check entity tags if they are not *
+            if ($ifMatch !== '*') {
+
+                // There can be multiple ETags
+                $ifMatch = explode(',', $ifMatch);
+                $haveMatch = false;
+                foreach ($ifMatch as $ifMatchItem) {
+
+                    // Stripping any extra spaces
+                    $ifMatchItem = trim($ifMatchItem, ' ');
+
+                    $etag = $node instanceof IFile ? $node->getETag() : null;
+                    if ($etag === $ifMatchItem) {
+                        $haveMatch = true;
+                    } else {
+                        // Evolution has a bug where it sometimes prepends the "
+                        // with a \. This is our workaround.
+                        if (str_replace('\\"', '"', $ifMatchItem) === $etag) {
+                            $haveMatch = true;
+                        }
+                    }
+
+                }
+                if (!$haveMatch) {
+                    if ($etag) $response->setHeader('ETag', $etag);
+                     throw new Exception\PreconditionFailed('An If-Match header was specified, but none of the specified the ETags matched.', 'If-Match');
+                }
+            }
+        }
+
+        if ($ifNoneMatch = $request->getHeader('If-None-Match')) {
+
+            // The If-None-Match header contains an ETag.
+            // Only if the ETag does not match the current ETag, the request will succeed
+            // The header can also contain *, in which case the request
+            // will only succeed if the entity does not exist at all.
+            $nodeExists = true;
+            if (!$node) {
+                try {
+                    $node = $this->tree->getNodeForPath($path);
+                } catch (Exception\NotFound $e) {
+                    $nodeExists = false;
+                }
+            }
+            if ($nodeExists) {
+                $haveMatch = false;
+                if ($ifNoneMatch === '*') $haveMatch = true;
+                else {
+
+                    // There might be multiple ETags
+                    $ifNoneMatch = explode(',', $ifNoneMatch);
+                    $etag = $node instanceof IFile ? $node->getETag() : null;
+
+                    foreach ($ifNoneMatch as $ifNoneMatchItem) {
+
+                        // Stripping any extra spaces
+                        $ifNoneMatchItem = trim($ifNoneMatchItem, ' ');
+
+                        if ($etag === $ifNoneMatchItem) $haveMatch = true;
+
+                    }
+
+                }
+
+                if ($haveMatch) {
+                    if ($etag) $response->setHeader('ETag', $etag);
+                    if ($request->getMethod() === 'GET') {
+                        $response->setStatus(304);
+                        return false;
+                    } else {
+                        throw new Exception\PreconditionFailed('An If-None-Match header was specified, but the ETag matched (or * was specified).', 'If-None-Match');
+                    }
+                }
+            }
+
+        }
+
+        if (!$ifNoneMatch && ($ifModifiedSince = $request->getHeader('If-Modified-Since'))) {
+
+            // The If-Modified-Since header contains a date. We
+            // will only return the entity if it has been changed since
+            // that date. If it hasn't been changed, we return a 304
+            // header
+            // Note that this header only has to be checked if there was no If-None-Match header
+            // as per the HTTP spec.
+            $date = HTTP\Util::parseHTTPDate($ifModifiedSince);
+
+            if ($date) {
+                if (is_null($node)) {
+                    $node = $this->tree->getNodeForPath($path);
+                }
+                $lastMod = $node->getLastModified();
+                if ($lastMod) {
+                    $lastMod = new \DateTime('@' . $lastMod);
+                    if ($lastMod <= $date) {
+                        $response->setStatus(304);
+                        $response->setHeader('Last-Modified', HTTP\Util::toHTTPDate($lastMod));
+                        return false;
+                    }
+                }
+            }
+        }
+
+        if ($ifUnmodifiedSince = $request->getHeader('If-Unmodified-Since')) {
+
+            // The If-Unmodified-Since will allow allow the request if the
+            // entity has not changed since the specified date.
+            $date = HTTP\Util::parseHTTPDate($ifUnmodifiedSince);
+
+            // We must only check the date if it's valid
+            if ($date) {
+                if (is_null($node)) {
+                    $node = $this->tree->getNodeForPath($path);
+                }
+                $lastMod = $node->getLastModified();
+                if ($lastMod) {
+                    $lastMod = new \DateTime('@' . $lastMod);
+                    if ($lastMod > $date) {
+                        throw new Exception\PreconditionFailed('An If-Unmodified-Since header was specified, but the entity has been changed since the specified date.', 'If-Unmodified-Since');
+                    }
+                }
+            }
+
+        }
+
+        // Now the hardest, the If: header. The If: header can contain multiple
+        // urls, ETags and so-called 'state tokens'.
+        //
+        // Examples of state tokens include lock-tokens (as defined in rfc4918)
+        // and sync-tokens (as defined in rfc6578).
+        //
+        // The only proper way to deal with these, is to emit events, that a
+        // Sync and Lock plugin can pick up.
+        $ifConditions = $this->getIfConditions($request);
+
+        foreach ($ifConditions as $kk => $ifCondition) {
+            foreach ($ifCondition['tokens'] as $ii => $token) {
+                $ifConditions[$kk]['tokens'][$ii]['validToken'] = false;
+            }
+        }
+
+        // Plugins are responsible for validating all the tokens.
+        // If a plugin deemed a token 'valid', it will set 'validToken' to
+        // true.
+        $this->emit('validateTokens', [ $request, &$ifConditions ]);
+
+        // Now we're going to analyze the result.
+
+        // Every ifCondition needs to validate to true, so we exit as soon as
+        // we have an invalid condition.
+        foreach ($ifConditions as $ifCondition) {
+
+            $uri = $ifCondition['uri'];
+            $tokens = $ifCondition['tokens'];
+
+            // We only need 1 valid token for the condition to succeed.
+            foreach ($tokens as $token) {
+
+                $tokenValid = $token['validToken'] || !$token['token'];
+
+                $etagValid = false;
+                if (!$token['etag']) {
+                    $etagValid = true;
+                }
+                // Checking the ETag, only if the token was already deamed
+                // valid and there is one.
+                if ($token['etag'] && $tokenValid) {
+
+                    // The token was valid, and there was an ETag. We must
+                    // grab the current ETag and check it.
+                    $node = $this->tree->getNodeForPath($uri);
+                    $etagValid = $node instanceof IFile && $node->getETag() == $token['etag'];
+
+                }
+
+
+                if (($tokenValid && $etagValid) ^ $token['negate']) {
+                    // Both were valid, so we can go to the next condition.
+                    continue 2;
+                }
+
+
+            }
+
+            // If we ended here, it means there was no valid ETag + token
+            // combination found for the current condition. This means we fail!
+            throw new Exception\PreconditionFailed('Failed to find a valid token/etag combination for ' . $uri, 'If');
+
+        }
+
+        return true;
+
+    }
+
+    /**
+     * This method is created to extract information from the WebDAV HTTP 'If:' header
+     *
+     * The If header can be quite complex, and has a bunch of features. We're using a regex to extract all relevant information
+     * The function will return an array, containing structs with the following keys
+     *
+     *   * uri   - the uri the condition applies to.
+     *   * tokens - The lock token. another 2 dimensional array containing 3 elements
+     *
+     * Example 1:
+     *
+     * If: (<opaquelocktoken:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)
+     *
+     * Would result in:
+     *
+     * [
+     *    [
+     *       'uri' => '/request/uri',
+     *       'tokens' => [
+     *          [
+     *              [
+     *                  'negate' => false,
+     *                  'token'  => 'opaquelocktoken:181d4fae-7d8c-11d0-a765-00a0c91e6bf2',
+     *                  'etag'   => ""
+     *              ]
+     *          ]
+     *       ],
+     *    ]
+     * ]
+     *
+     * Example 2:
+     *
+     * If: </path/> (Not <opaquelocktoken:181d4fae-7d8c-11d0-a765-00a0c91e6bf2> ["Im An ETag"]) (["Another ETag"]) </path2/> (Not ["Path2 ETag"])
+     *
+     * Would result in:
+     *
+     * [
+     *    [
+     *       'uri' => 'path',
+     *       'tokens' => [
+     *          [
+     *              [
+     *                  'negate' => true,
+     *                  'token'  => 'opaquelocktoken:181d4fae-7d8c-11d0-a765-00a0c91e6bf2',
+     *                  'etag'   => '"Im An ETag"'
+     *              ],
+     *              [
+     *                  'negate' => false,
+     *                  'token'  => '',
+     *                  'etag'   => '"Another ETag"'
+     *              ]
+     *          ]
+     *       ],
+     *    ],
+     *    [
+     *       'uri' => 'path2',
+     *       'tokens' => [
+     *          [
+     *              [
+     *                  'negate' => true,
+     *                  'token'  => '',
+     *                  'etag'   => '"Path2 ETag"'
+     *              ]
+     *          ]
+     *       ],
+     *    ],
+     * ]
+     *
+     * @param RequestInterface $request
+     * @return array
+     */
+    function getIfConditions(RequestInterface $request) {
+
+        $header = $request->getHeader('If');
+        if (!$header) return [];
+
+        $matches = [];
+
+        $regex = '/(?:\<(?P<uri>.*?)\>\s)?\((?P<not>Not\s)?(?:\<(?P<token>[^\>]*)\>)?(?:\s?)(?:\[(?P<etag>[^\]]*)\])?\)/im';
+        preg_match_all($regex, $header, $matches, PREG_SET_ORDER);
+
+        $conditions = [];
+
+        foreach ($matches as $match) {
+
+            // If there was no uri specified in this match, and there were
+            // already conditions parsed, we add the condition to the list of
+            // conditions for the previous uri.
+            if (!$match['uri'] && count($conditions)) {
+                $conditions[count($conditions) - 1]['tokens'][] = [
+                    'negate' => $match['not'] ? true : false,
+                    'token'  => $match['token'],
+                    'etag'   => isset($match['etag']) ? $match['etag'] : ''
+                ];
+            } else {
+
+                if (!$match['uri']) {
+                    $realUri = $request->getPath();
+                } else {
+                    $realUri = $this->calculateUri($match['uri']);
+                }
+
+                $conditions[] = [
+                    'uri'    => $realUri,
+                    'tokens' => [
+                        [
+                            'negate' => $match['not'] ? true : false,
+                            'token'  => $match['token'],
+                            'etag'   => isset($match['etag']) ? $match['etag'] : ''
+                        ]
+                    ],
+
+                ];
+            }
+
+        }
+
+        return $conditions;
+
+    }
+
+    /**
+     * Returns an array with resourcetypes for a node.
+     *
+     * @param INode $node
+     * @return array
+     */
+    function getResourceTypeForNode(INode $node) {
+
+        $result = [];
+        foreach ($this->resourceTypeMapping as $className => $resourceType) {
+            if ($node instanceof $className) $result[] = $resourceType;
+        }
+        return $result;
+
+    }
+
+    // }}}
+    // {{{ XML Readers & Writers
+
+
+    /**
+     * Generates a WebDAV propfind response body based on a list of nodes.
+     *
+     * If 'strip404s' is set to true, all 404 responses will be removed.
+     *
+     * @param array $fileProperties The list with nodes
+     * @param bool strip404s
+     * @return string
+     */
+    function generateMultiStatus(array $fileProperties, $strip404s = false) {
+
+        $xml = [];
+
+        foreach ($fileProperties as $entry) {
+
+            $href = $entry['href'];
+            unset($entry['href']);
+            if ($strip404s) {
+                unset($entry[404]);
+            }
+            $response = new Xml\Element\Response(
+                ltrim($href, '/'),
+                $entry
+            );
+            $xml[] = [
+                'name'  => '{DAV:}response',
+                'value' => $response
+            ];
+
+        }
+        return $this->xml->write('{DAV:}multistatus', $xml, $this->baseUri);
+
+    }
+
+}