4 * Parser that uses PHP 5's DOM extension (part of the core).
6 * In PHP 5, the DOM XML extension was revamped into DOM and added to the core.
7 * It gives us a forgiving HTML parser, which we use to transform the HTML
8 * into a DOM, and then into the tokens. It is blazingly fast (for large
9 * documents, it performs twenty times faster than
10 * HTMLPurifier_Lexer_DirectLex,and is the default choice for PHP 5.
12 * @note Any empty elements will have empty tokens associated with them, even if
13 * this is prohibited by the spec. This is cannot be fixed until the spec
16 * @note PHP's DOM extension does not actually parse any entities, we use
17 * our own function to do that.
19 * @warning DOM tends to drop whitespace, which may wreak havoc on indenting.
20 * If this is a huge problem, due to the fact that HTML is hand
21 * edited and you are unable to get a parser cache that caches the
22 * the output of HTML Purifier while keeping the original HTML lying
23 * around, you may want to run Tidy on the resulting output or use
24 * HTMLPurifier_DirectLex
27 class HTMLPurifier_Lexer_DOMLex
extends HTMLPurifier_Lexer
31 * @type HTMLPurifier_TokenFactory
35 public function __construct()
38 parent
::__construct();
39 $this->factory
= new HTMLPurifier_TokenFactory();
44 * @param HTMLPurifier_Config $config
45 * @param HTMLPurifier_Context $context
46 * @return HTMLPurifier_Token[]
48 public function tokenizeHTML($html, $config, $context)
50 $html = $this->normalize($html, $config, $context);
52 // attempt to armor stray angled brackets that cannot possibly
53 // form tags and thus are probably being used as emoticons
54 if ($config->get('Core.AggressivelyFixLt')) {
56 $comment = "/<!--(.*?)(-->|\z)/is";
57 $html = preg_replace_callback($comment, array($this, 'callbackArmorCommentEntities'), $html);
60 $html = preg_replace("/<($char)/i", '<\\1', $html);
61 } while ($html !== $old);
62 $html = preg_replace_callback($comment, array($this, 'callbackUndoCommentSubst'), $html); // fix comments
65 // preprocess html, essential for UTF-8
66 $html = $this->wrapHTML($html, $config, $context);
68 $doc = new DOMDocument();
69 $doc->encoding
= 'UTF-8'; // theoretically, the above has this covered
71 set_error_handler(array($this, 'muteErrorHandler'));
72 $doc->loadHTML($html);
73 restore_error_handler();
75 $body = $doc->getElementsByTagName('html')->item(0)-> // <html>
76 getElementsByTagName('body')->item(0); // <body>
78 $div = $body->getElementsByTagName('div')->item(0); // <div>
80 $this->tokenizeDOM($div, $tokens, $config);
81 // If the div has a sibling, that means we tripped across
82 // a premature </div> tag. So remove the div we parsed,
83 // and then tokenize the rest of body. We can't tokenize
84 // the sibling directly as we'll lose the tags in that case.
85 if ($div->nextSibling
) {
86 $body->removeChild($div);
87 $this->tokenizeDOM($body, $tokens, $config);
93 * Iterative function that tokenizes a node, putting it into an accumulator.
94 * To iterate is human, to recurse divine - L. Peter Deutsch
95 * @param DOMNode $node DOMNode to be tokenized.
96 * @param HTMLPurifier_Token[] $tokens Array-list of already tokenized tokens.
97 * @return HTMLPurifier_Token of node appended to previously passed tokens.
99 protected function tokenizeDOM($node, &$tokens, $config)
102 $nodes = array($level => new HTMLPurifier_Queue(array($node)));
103 $closingNodes = array();
105 while (!$nodes[$level]->isEmpty()) {
106 $node = $nodes[$level]->shift(); // FIFO
107 $collect = $level > 0 ?
true : false;
108 $needEndingTag = $this->createStartNode($node, $tokens, $collect, $config);
109 if ($needEndingTag) {
110 $closingNodes[$level][] = $node;
112 if ($node->childNodes
&& $node->childNodes
->length
) {
114 $nodes[$level] = new HTMLPurifier_Queue();
115 foreach ($node->childNodes
as $childNode) {
116 $nodes[$level]->push($childNode);
121 if ($level && isset($closingNodes[$level])) {
122 while ($node = array_pop($closingNodes[$level])) {
123 $this->createEndNode($node, $tokens);
126 } while ($level > 0);
130 * @param DOMNode $node DOMNode to be tokenized.
131 * @param HTMLPurifier_Token[] $tokens Array-list of already tokenized tokens.
132 * @param bool $collect Says whether or start and close are collected, set to
133 * false at first recursion because it's the implicit DIV
134 * tag you're dealing with.
135 * @return bool if the token needs an endtoken
136 * @todo data and tagName properties don't seem to exist in DOMNode?
138 protected function createStartNode($node, &$tokens, $collect, $config)
140 // intercept non element nodes. WE MUST catch all of them,
141 // but we're not getting the character reference nodes because
142 // those should have been preprocessed
143 if ($node->nodeType
=== XML_TEXT_NODE
) {
144 $tokens[] = $this->factory
->createText($node->data
);
146 } elseif ($node->nodeType
=== XML_CDATA_SECTION_NODE
) {
147 // undo libxml's special treatment of <script> and <style> tags
148 $last = end($tokens);
150 // (note $node->tagname is already normalized)
151 if ($last instanceof HTMLPurifier_Token_Start
&& ($last->name
== 'script' ||
$last->name
== 'style')) {
152 $new_data = trim($data);
153 if (substr($new_data, 0, 4) === '<!--') {
154 $data = substr($new_data, 4);
155 if (substr($data, -3) === '-->') {
156 $data = substr($data, 0, -3);
158 // Highly suspicious! Not sure what to do...
162 $tokens[] = $this->factory
->createText($this->parseText($data, $config));
164 } elseif ($node->nodeType
=== XML_COMMENT_NODE
) {
165 // this is code is only invoked for comments in script/style in versions
166 // of libxml pre-2.6.28 (regular comments, of course, are still
167 // handled regularly)
168 $tokens[] = $this->factory
->createComment($node->data
);
170 } elseif ($node->nodeType
!== XML_ELEMENT_NODE
) {
171 // not-well tested: there may be other nodes we have to grab
175 $attr = $node->hasAttributes() ?
$this->transformAttrToAssoc($node->attributes
) : array();
177 // We still have to make sure that the element actually IS empty
178 if (!$node->childNodes
->length
) {
180 $tokens[] = $this->factory
->createEmpty($node->tagName
, $attr);
185 $tokens[] = $this->factory
->createStart(
186 $tag_name = $node->tagName
, // somehow, it get's dropped
195 * @param DOMNode $node
196 * @param HTMLPurifier_Token[] $tokens
198 protected function createEndNode($node, &$tokens)
200 $tokens[] = $this->factory
->createEnd($node->tagName
);
205 * Converts a DOMNamedNodeMap of DOMAttr objects into an assoc array.
207 * @param DOMNamedNodeMap $node_map DOMNamedNodeMap of DOMAttr objects.
208 * @return array Associative array of attributes.
210 protected function transformAttrToAssoc($node_map)
212 // NamedNodeMap is documented very well, so we're using undocumented
213 // features, namely, the fact that it implements Iterator and
214 // has a ->length attribute
215 if ($node_map->length
=== 0) {
219 foreach ($node_map as $attr) {
220 $array[$attr->name
] = $attr->value
;
226 * An error handler that mutes all errors
228 * @param string $errstr
230 public function muteErrorHandler($errno, $errstr)
235 * Callback function for undoing escaping of stray angled brackets
237 * @param array $matches
240 public function callbackUndoCommentSubst($matches)
242 return '<!--' . strtr($matches[1], array('&' => '&', '<' => '<')) . $matches[2];
246 * Callback function that entity-izes ampersands in comments so that
247 * callbackUndoCommentSubst doesn't clobber them
248 * @param array $matches
251 public function callbackArmorCommentEntities($matches)
253 return '<!--' . str_replace('&', '&', $matches[1]) . $matches[2];
257 * Wraps an HTML fragment in the necessary HTML
258 * @param string $html
259 * @param HTMLPurifier_Config $config
260 * @param HTMLPurifier_Context $context
263 protected function wrapHTML($html, $config, $context, $use_div = true)
265 $def = $config->getDefinition('HTML');
268 if (!empty($def->doctype
->dtdPublic
) ||
!empty($def->doctype
->dtdSystem
)) {
269 $ret .= '<!DOCTYPE html ';
270 if (!empty($def->doctype
->dtdPublic
)) {
271 $ret .= 'PUBLIC "' . $def->doctype
->dtdPublic
. '" ';
273 if (!empty($def->doctype
->dtdSystem
)) {
274 $ret .= '"' . $def->doctype
->dtdSystem
. '" ';
279 $ret .= '<html><head>';
280 $ret .= '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />';
281 // No protection if $html contains a stray </div>!
282 $ret .= '</head><body>';
283 if ($use_div) $ret .= '<div>';
285 if ($use_div) $ret .= '</div>';
286 $ret .= '</body></html>';
291 // vim: et sw=4 sts=4