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Diffstat (limited to 'library/HTMLPurifier/Lexer.php')
| -rw-r--r-- | library/HTMLPurifier/Lexer.php | 357 |
1 files changed, 0 insertions, 357 deletions
diff --git a/library/HTMLPurifier/Lexer.php b/library/HTMLPurifier/Lexer.php deleted file mode 100644 index 43732621d..000000000 --- a/library/HTMLPurifier/Lexer.php +++ /dev/null @@ -1,357 +0,0 @@ -<?php - -/** - * Forgivingly lexes HTML (SGML-style) markup into tokens. - * - * A lexer parses a string of SGML-style markup and converts them into - * corresponding tokens. It doesn't check for well-formedness, although its - * internal mechanism may make this automatic (such as the case of - * HTMLPurifier_Lexer_DOMLex). There are several implementations to choose - * from. - * - * A lexer is HTML-oriented: it might work with XML, but it's not - * recommended, as we adhere to a subset of the specification for optimization - * reasons. This might change in the future. Also, most tokenizers are not - * expected to handle DTDs or PIs. - * - * This class should not be directly instantiated, but you may use create() to - * retrieve a default copy of the lexer. Being a supertype, this class - * does not actually define any implementation, but offers commonly used - * convenience functions for subclasses. - * - * @note The unit tests will instantiate this class for testing purposes, as - * many of the utility functions require a class to be instantiated. - * This means that, even though this class is not runnable, it will - * not be declared abstract. - * - * @par - * - * @note - * We use tokens rather than create a DOM representation because DOM would: - * - * @par - * -# Require more processing and memory to create, - * -# Is not streamable, and - * -# Has the entire document structure (html and body not needed). - * - * @par - * However, DOM is helpful in that it makes it easy to move around nodes - * without a lot of lookaheads to see when a tag is closed. This is a - * limitation of the token system and some workarounds would be nice. - */ -class HTMLPurifier_Lexer -{ - - /** - * Whether or not this lexer implements line-number/column-number tracking. - * If it does, set to true. - */ - public $tracksLineNumbers = false; - - // -- STATIC ---------------------------------------------------------- - - /** - * Retrieves or sets the default Lexer as a Prototype Factory. - * - * By default HTMLPurifier_Lexer_DOMLex will be returned. There are - * a few exceptions involving special features that only DirectLex - * implements. - * - * @note The behavior of this class has changed, rather than accepting - * a prototype object, it now accepts a configuration object. - * To specify your own prototype, set %Core.LexerImpl to it. - * This change in behavior de-singletonizes the lexer object. - * - * @param HTMLPurifier_Config $config - * @return HTMLPurifier_Lexer - * @throws HTMLPurifier_Exception - */ - public static function create($config) - { - if (!($config instanceof HTMLPurifier_Config)) { - $lexer = $config; - trigger_error( - "Passing a prototype to - HTMLPurifier_Lexer::create() is deprecated, please instead - use %Core.LexerImpl", - E_USER_WARNING - ); - } else { - $lexer = $config->get('Core.LexerImpl'); - } - - $needs_tracking = - $config->get('Core.MaintainLineNumbers') || - $config->get('Core.CollectErrors'); - - $inst = null; - if (is_object($lexer)) { - $inst = $lexer; - } else { - if (is_null($lexer)) { - do { - // auto-detection algorithm - if ($needs_tracking) { - $lexer = 'DirectLex'; - break; - } - - if (class_exists('DOMDocument') && - method_exists('DOMDocument', 'loadHTML') && - !extension_loaded('domxml') - ) { - // check for DOM support, because while it's part of the - // core, it can be disabled compile time. Also, the PECL - // domxml extension overrides the default DOM, and is evil - // and nasty and we shan't bother to support it - $lexer = 'DOMLex'; - } else { - $lexer = 'DirectLex'; - } - } while (0); - } // do..while so we can break - - // instantiate recognized string names - switch ($lexer) { - case 'DOMLex': - $inst = new HTMLPurifier_Lexer_DOMLex(); - break; - case 'DirectLex': - $inst = new HTMLPurifier_Lexer_DirectLex(); - break; - case 'PH5P': - $inst = new HTMLPurifier_Lexer_PH5P(); - break; - default: - throw new HTMLPurifier_Exception( - "Cannot instantiate unrecognized Lexer type " . - htmlspecialchars($lexer) - ); - } - } - - if (!$inst) { - throw new HTMLPurifier_Exception('No lexer was instantiated'); - } - - // once PHP DOM implements native line numbers, or we - // hack out something using XSLT, remove this stipulation - if ($needs_tracking && !$inst->tracksLineNumbers) { - throw new HTMLPurifier_Exception( - 'Cannot use lexer that does not support line numbers with ' . - 'Core.MaintainLineNumbers or Core.CollectErrors (use DirectLex instead)' - ); - } - - return $inst; - - } - - // -- CONVENIENCE MEMBERS --------------------------------------------- - - public function __construct() - { - $this->_entity_parser = new HTMLPurifier_EntityParser(); - } - - /** - * Most common entity to raw value conversion table for special entities. - * @type array - */ - protected $_special_entity2str = - array( - '"' => '"', - '&' => '&', - '<' => '<', - '>' => '>', - ''' => "'", - ''' => "'", - ''' => "'" - ); - - /** - * Parses special entities into the proper characters. - * - * This string will translate escaped versions of the special characters - * into the correct ones. - * - * @warning - * You should be able to treat the output of this function as - * completely parsed, but that's only because all other entities should - * have been handled previously in substituteNonSpecialEntities() - * - * @param string $string String character data to be parsed. - * @return string Parsed character data. - */ - public function parseData($string) - { - // following functions require at least one character - if ($string === '') { - return ''; - } - - // subtracts amps that cannot possibly be escaped - $num_amp = substr_count($string, '&') - substr_count($string, '& ') - - ($string[strlen($string) - 1] === '&' ? 1 : 0); - - if (!$num_amp) { - return $string; - } // abort if no entities - $num_esc_amp = substr_count($string, '&'); - $string = strtr($string, $this->_special_entity2str); - - // code duplication for sake of optimization, see above - $num_amp_2 = substr_count($string, '&') - substr_count($string, '& ') - - ($string[strlen($string) - 1] === '&' ? 1 : 0); - - if ($num_amp_2 <= $num_esc_amp) { - return $string; - } - - // hmm... now we have some uncommon entities. Use the callback. - $string = $this->_entity_parser->substituteSpecialEntities($string); - return $string; - } - - /** - * Lexes an HTML string into tokens. - * @param $string String HTML. - * @param HTMLPurifier_Config $config - * @param HTMLPurifier_Context $context - * @return HTMLPurifier_Token[] array representation of HTML. - */ - public function tokenizeHTML($string, $config, $context) - { - trigger_error('Call to abstract class', E_USER_ERROR); - } - - /** - * Translates CDATA sections into regular sections (through escaping). - * @param string $string HTML string to process. - * @return string HTML with CDATA sections escaped. - */ - protected static function escapeCDATA($string) - { - return preg_replace_callback( - '/<!\[CDATA\[(.+?)\]\]>/s', - array('HTMLPurifier_Lexer', 'CDATACallback'), - $string - ); - } - - /** - * Special CDATA case that is especially convoluted for <script> - * @param string $string HTML string to process. - * @return string HTML with CDATA sections escaped. - */ - protected static function escapeCommentedCDATA($string) - { - return preg_replace_callback( - '#<!--//--><!\[CDATA\[//><!--(.+?)//--><!\]\]>#s', - array('HTMLPurifier_Lexer', 'CDATACallback'), - $string - ); - } - - /** - * Special Internet Explorer conditional comments should be removed. - * @param string $string HTML string to process. - * @return string HTML with conditional comments removed. - */ - protected static function removeIEConditional($string) - { - return preg_replace( - '#<!--\[if [^>]+\]>.*?<!\[endif\]-->#si', // probably should generalize for all strings - '', - $string - ); - } - - /** - * Callback function for escapeCDATA() that does the work. - * - * @warning Though this is public in order to let the callback happen, - * calling it directly is not recommended. - * @param array $matches PCRE matches array, with index 0 the entire match - * and 1 the inside of the CDATA section. - * @return string Escaped internals of the CDATA section. - */ - protected static function CDATACallback($matches) - { - // not exactly sure why the character set is needed, but whatever - return htmlspecialchars($matches[1], ENT_COMPAT, 'UTF-8'); - } - - /** - * Takes a piece of HTML and normalizes it by converting entities, fixing - * encoding, extracting bits, and other good stuff. - * @param string $html HTML. - * @param HTMLPurifier_Config $config - * @param HTMLPurifier_Context $context - * @return string - * @todo Consider making protected - */ - public function normalize($html, $config, $context) - { - // normalize newlines to \n - if ($config->get('Core.NormalizeNewlines')) { - $html = str_replace("\r\n", "\n", $html); - $html = str_replace("\r", "\n", $html); - } - - if ($config->get('HTML.Trusted')) { - // escape convoluted CDATA - $html = $this->escapeCommentedCDATA($html); - } - - // escape CDATA - $html = $this->escapeCDATA($html); - - $html = $this->removeIEConditional($html); - - // extract body from document if applicable - if ($config->get('Core.ConvertDocumentToFragment')) { - $e = false; - if ($config->get('Core.CollectErrors')) { - $e =& $context->get('ErrorCollector'); - } - $new_html = $this->extractBody($html); - if ($e && $new_html != $html) { - $e->send(E_WARNING, 'Lexer: Extracted body'); - } - $html = $new_html; - } - - // expand entities that aren't the big five - $html = $this->_entity_parser->substituteNonSpecialEntities($html); - - // clean into wellformed UTF-8 string for an SGML context: this has - // to be done after entity expansion because the entities sometimes - // represent non-SGML characters (horror, horror!) - $html = HTMLPurifier_Encoder::cleanUTF8($html); - - // if processing instructions are to removed, remove them now - if ($config->get('Core.RemoveProcessingInstructions')) { - $html = preg_replace('#<\?.+?\?>#s', '', $html); - } - - return $html; - } - - /** - * Takes a string of HTML (fragment or document) and returns the content - * @todo Consider making protected - */ - public function extractBody($html) - { - $matches = array(); - $result = preg_match('!<body[^>]*>(.*)</body>!is', $html, $matches); - if ($result) { - return $matches[1]; - } else { - return $html; - } - } -} - -// vim: et sw=4 sts=4 |