HTMLPurifier_Lexer_DOMLex Class Reference

Parser that uses PHP 5's DOM extension (part of the core). More...

Inheritance diagram for HTMLPurifier_Lexer_DOMLex:

Collaboration diagram for HTMLPurifier_Lexer_DOMLex:

Public Member Functions
	__construct ()
	tokenizeHTML ($html, $config, $context)
	Lexes an HTML string into tokens.
	muteErrorHandler ($errno, $errstr)
	An error handler that mutes all errors.
	callbackUndoCommentSubst ($matches)
	Callback function for undoing escaping of stray angled brackets in comments.
	callbackArmorCommentEntities ($matches)
	Callback function that entity-izes ampersands in comments so that callbackUndoCommentSubst doesn't clobber them.
Public Member Functions inherited from HTMLPurifier_Lexer
	parseData ($string)
	Parses special entities into the proper characters.
	normalize ($html, $config, $context)
	Takes a piece of HTML and normalizes it by converting entities, fixing encoding, extracting bits, and other good stuff.
	extractBody ($html)
	Takes a string of HTML (fragment or document) and returns the content.

Protected Member Functions
	tokenizeDOM ($node, &$tokens)
	Iterative function that tokenizes a node, putting it into an accumulator.
	createStartNode ($node, &$tokens, $collect)
	createEndNode ($node, &$tokens)
	transformAttrToAssoc ($node_map)
	Converts a DOMNamedNodeMap of DOMAttr objects into an assoc array.
	wrapHTML ($html, $config, $context)
	Wraps an HTML fragment in the necessary HTML.

Private Attributes
	$factory

Additional Inherited Members
Static Public Member Functions inherited from HTMLPurifier_Lexer
static	create ($config)
	Retrieves or sets the default Lexer as a Prototype Factory.
Data Fields inherited from HTMLPurifier_Lexer
	$tracksLineNumbers = false
	Whether or not this lexer implements line-number/column-number tracking.
Static Protected Member Functions inherited from HTMLPurifier_Lexer
static	escapeCDATA ($string)
	Translates CDATA sections into regular sections (through escaping).
static	escapeCommentedCDATA ($string)
	Special CDATA case that is especially convoluted for <script>
static	removeIEConditional ($string)
	Special Internet Explorer conditional comments should be removed.
static	CDATACallback ($matches)
	Callback function for escapeCDATA() that does the work.
Protected Attributes inherited from HTMLPurifier_Lexer
	$_special_entity2str
	Most common entity to raw value conversion table for special entities.

Detailed Description

Parser that uses PHP 5's DOM extension (part of the core).

In PHP 5, the DOM XML extension was revamped into DOM and added to the core. It gives us a forgiving HTML parser, which we use to transform the HTML into a DOM, and then into the tokens. It is blazingly fast (for large documents, it performs twenty times faster than HTMLPurifier_Lexer_DirectLex,and is the default choice for PHP 5.

Note

Any empty elements will have empty tokens associated with them, even if this is prohibited by the spec. This is cannot be fixed until the spec comes into play.

PHP's DOM extension does not actually parse any entities, we use our own function to do that.

Warning

DOM tends to drop whitespace, which may wreak havoc on indenting. If this is a huge problem, due to the fact that HTML is hand edited and you are unable to get a parser cache that caches the the output of HTML Purifier while keeping the original HTML lying around, you may want to run Tidy on the resulting output or use HTMLPurifier_DirectLex

Definition at line 27 of file DOMLex.php.

Constructor & Destructor Documentation

HTMLPurifier_Lexer_DOMLex::__construct

(

)

Reimplemented from HTMLPurifier_Lexer.

Definition at line 32 of file DOMLex.php.

                                  {
        // setup the factory
        parent::__construct();
        $this->factory = new HTMLPurifier_TokenFactory();
    }

Member Function Documentation

HTMLPurifier_Lexer_DOMLex::callbackArmorCommentEntities

(

$matches

)

Callback function that entity-izes ampersands in comments so that callbackUndoCommentSubst doesn't clobber them.

Definition at line 216 of file DOMLex.php.

                                                           {
        return '<!--' . str_replace('&', '&amp;', $matches[1]) . $matches[2];
    }

HTMLPurifier_Lexer_DOMLex::callbackUndoCommentSubst

(

$matches

)

Callback function for undoing escaping of stray angled brackets in comments.

Definition at line 208 of file DOMLex.php.

                                                       {
        return '<!--' . strtr($matches[1], array('&amp;'=>'&','&lt;'=>'<')) . $matches[2];
    }

HTMLPurifier_Lexer_DOMLex::createEndNode (   $node, &  $tokens  )

protected

Definition at line 176 of file DOMLex.php.

Referenced by tokenizeDOM().

                                                      {
        $tokens[] = $this->factory->createEnd($node->tagName);
    }

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HTMLPurifier_Lexer_DOMLex::createStartNode (   $node, &  $tokens,   $collect  )

protected

Parameters

$node	DOMNode to be tokenized.
$tokens	Array-list of already tokenized tokens.
$collect	Says whether or start and close are collected, set to false at first recursion because it's the implicit DIV tag you're dealing with.

Returns

bool if the token needs an endtoken

Definition at line 119 of file DOMLex.php.

References $data, HTMLPurifier_Lexer\parseData(), and transformAttrToAssoc().

Referenced by tokenizeDOM().

                                                                  {
        // intercept non element nodes. WE MUST catch all of them,
        // but we're not getting the character reference nodes because
        // those should have been preprocessed
        if ($node->nodeType === XML_TEXT_NODE) {
            $tokens[] = $this->factory->createText($node->data);
            return false;
        } elseif ($node->nodeType === XML_CDATA_SECTION_NODE) {
            // undo libxml's special treatment of <script> and <style> tags
            $last = end($tokens);
            $data = $node->data;
            // (note $node->tagname is already normalized)
            if ($last instanceof HTMLPurifier_Token_Start && ($last->name == 'script' || $last->name == 'style')) {
                $new_data = trim($data);
                if (substr($new_data, 0, 4) === '<!--') {
                    $data = substr($new_data, 4);
                    if (substr($data, -3) === '-->') {
                        $data = substr($data, 0, -3);
                    } else {
                        // Highly suspicious! Not sure what to do...
                    }
                }
            }
            $tokens[] = $this->factory->createText($this->parseData($data));
            return false;
        } elseif ($node->nodeType === XML_COMMENT_NODE) {
            // this is code is only invoked for comments in script/style in versions
            // of libxml pre-2.6.28 (regular comments, of course, are still
            // handled regularly)
            $tokens[] = $this->factory->createComment($node->data);
            return false;
        } elseif (
            // not-well tested: there may be other nodes we have to grab
            $node->nodeType !== XML_ELEMENT_NODE
        ) {
            return false;
        }

        $attr = $node->hasAttributes() ? $this->transformAttrToAssoc($node->attributes) : array();

        // We still have to make sure that the element actually IS empty
        if (!$node->childNodes->length) {
            if ($collect) {
                $tokens[] = $this->factory->createEmpty($node->tagName, $attr);
            }
            return false;
        } else {
            if ($collect) {
                $tokens[] = $this->factory->createStart(
                    $tag_name = $node->tagName, // somehow, it get's dropped
                    $attr
                );
            }
            return true;
        }
    }

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HTMLPurifier_Lexer_DOMLex::muteErrorHandler	(		$errno,
			$errstr
	)

An error handler that mutes all errors.

Definition at line 202 of file DOMLex.php.

{}

HTMLPurifier_Lexer_DOMLex::tokenizeDOM (   $node, &  $tokens  )

protected

Iterative function that tokenizes a node, putting it into an accumulator.

To iterate is human, to recurse divine - L. Peter Deutsch

Parameters

$node	DOMNode to be tokenized.
$tokens	Array-list of already tokenized tokens.

Returns

Tokens of node appended to previously passed tokens.

Definition at line 81 of file DOMLex.php.

References createEndNode(), and createStartNode().

Referenced by HTMLPurifier_Lexer_PH5P\tokenizeHTML(), and tokenizeHTML().

                                                    {

        $level = 0;
        $nodes = array($level => array($node));
        $closingNodes = array();
        do {
            while (!empty($nodes[$level])) {
                $node = array_shift($nodes[$level]); // FIFO
                $collect = $level > 0 ? true : false;
                $needEndingTag = $this->createStartNode($node, $tokens, $collect);
                if ($needEndingTag) {
                    $closingNodes[$level][] = $node;
                }
                if ($node->childNodes && $node->childNodes->length) {
                    $level++;
                    $nodes[$level] = array();
                    foreach ($node->childNodes as $childNode) {
                        array_push($nodes[$level], $childNode);
                    }
                }
            }
            $level--;
            if ($level && isset($closingNodes[$level])) {
                while($node = array_pop($closingNodes[$level])) {
                    $this->createEndNode($node, $tokens);
                }
            }
        } while ($level > 0);
    }

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HTMLPurifier_Lexer_DOMLex::tokenizeHTML	(		$string,
			$config,
			$context
	)

Lexes an HTML string into tokens.

Parameters

$string

String HTML.

Returns

HTMLPurifier_Token array representation of HTML.

Reimplemented from HTMLPurifier_Lexer.

Reimplemented in HTMLPurifier_Lexer_PH5P.

Definition at line 38 of file DOMLex.php.

References $comment, $config, HTMLPurifier_Lexer\normalize(), tokenizeDOM(), and wrapHTML().

                                                           {

        $html = $this->normalize($html, $config, $context);

        // attempt to armor stray angled brackets that cannot possibly
        // form tags and thus are probably being used as emoticons
        if ($config->get('Core.AggressivelyFixLt')) {
            $char = '[^a-z!\/]';
            $comment = "/<!--(.*?)(-->|\z)/is";
            $html = preg_replace_callback($comment, array($this, 'callbackArmorCommentEntities'), $html);
            do {
                $old = $html;
                $html = preg_replace("/<($char)/i", '&lt;\\1', $html);
            } while ($html !== $old);
            $html = preg_replace_callback($comment, array($this, 'callbackUndoCommentSubst'), $html); // fix comments
        }

        // preprocess html, essential for UTF-8
        $html = $this->wrapHTML($html, $config, $context);

        $doc = new DOMDocument();
        $doc->encoding = 'UTF-8'; // theoretically, the above has this covered

        set_error_handler(array($this, 'muteErrorHandler'));
        $doc->loadHTML($html);
        restore_error_handler();

        $tokens = array();
        $this->tokenizeDOM(
            $doc->getElementsByTagName('html')->item(0)-> // <html>
                  getElementsByTagName('body')->item(0)-> //   <body>
                  getElementsByTagName('div')->item(0)    //     <div>
            , $tokens);
        return $tokens;
    }

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HTMLPurifier_Lexer_DOMLex::transformAttrToAssoc (   $node_map )

protected

Converts a DOMNamedNodeMap of DOMAttr objects into an assoc array.

Parameters

$attribute_list

DOMNamedNodeMap of DOMAttr objects.

Returns

Associative array of attributes.

Definition at line 187 of file DOMLex.php.

Referenced by createStartNode().

                                                       {
        // NamedNodeMap is documented very well, so we're using undocumented
        // features, namely, the fact that it implements Iterator and
        // has a ->length attribute
        if ($node_map->length === 0) return array();
        $array = array();
        foreach ($node_map as $attr) {
            $array[$attr->name] = $attr->value;
        }
        return $array;
    }

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HTMLPurifier_Lexer_DOMLex::wrapHTML (   $html,   $config,   $context  )

protected

Wraps an HTML fragment in the necessary HTML.

Definition at line 223 of file DOMLex.php.

References $config, and $ret.

Referenced by HTMLPurifier_Lexer_PH5P\tokenizeHTML(), and tokenizeHTML().

                                                          {
        $def = $config->getDefinition('HTML');
        $ret = '';

        if (!empty($def->doctype->dtdPublic) || !empty($def->doctype->dtdSystem)) {
            $ret .= '<!DOCTYPE html ';
            if (!empty($def->doctype->dtdPublic)) $ret .= 'PUBLIC "' . $def->doctype->dtdPublic . '" ';
            if (!empty($def->doctype->dtdSystem)) $ret .= '"' . $def->doctype->dtdSystem . '" ';
            $ret .= '>';
        }

        $ret .= '<html><head>';
        $ret .= '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />';
        // No protection if $html contains a stray </div>!
        $ret .= '</head><body><div>'.$html.'</div></body></html>';
        return $ret;
    }

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Field Documentation

HTMLPurifier_Lexer_DOMLex::$factory

private

Definition at line 30 of file DOMLex.php.

---

The documentation for this class was generated from the following file:

• Services/Html/HtmlPurifier/library/HTMLPurifier/Lexer/DOMLex.php