-class HtmlFormatter {
- /**
- * @var DOMDocument
- */
- private $doc;
-
- private $html;
- private $itemsToRemove = array();
- private $elementsToFlatten = array();
- protected $removeMedia = false;
-
- /**
- * Constructor
- *
- * @param string $html Text to process
- */
- public function __construct( $html ) {
- $this->html = $html;
- }
-
- /**
- * Turns a chunk of HTML into a proper document
- * @param string $html
- * @return string
- */
- public static function wrapHTML( $html ) {
- return '<!doctype html><html><head></head><body>' . $html . '</body></html>';
- }
-
- /**
- * Override this in descendant class to modify HTML after it has been converted from DOM tree
- * @param string $html HTML to process
- * @return string Processed HTML
- */
- protected function onHtmlReady( $html ) {
- return $html;
- }
-
- /**
- * @return DOMDocument DOM to manipulate
- */
- public function getDoc() {
- if ( !$this->doc ) {
- // DOMDocument::loadHTML apparently isn't very good with encodings, so
- // convert input to ASCII by encoding everything above 128 as entities.
- if ( function_exists( 'mb_convert_encoding' ) ) {
- $html = mb_convert_encoding( $this->html, 'HTML-ENTITIES', 'UTF-8' );
- } else {
- $html = preg_replace_callback( '/[\x{80}-\x{10ffff}]/u', function ( $m ) {
- return '&#' . UtfNormal\Utils::utf8ToCodepoint( $m[0] ) . ';';
- }, $this->html );
- }
-
- // Workaround for bug that caused spaces before references
- // to disappear during processing:
- // https://bugzilla.wikimedia.org/show_bug.cgi?id=53086
- //
- // Please replace with a better fix if one can be found.
- $html = str_replace( ' <', ' <', $html );
-
- libxml_use_internal_errors( true );
- $loader = libxml_disable_entity_loader();
- $this->doc = new DOMDocument();
- $this->doc->strictErrorChecking = false;
- $this->doc->loadHTML( $html );
- libxml_disable_entity_loader( $loader );
- libxml_use_internal_errors( false );
- $this->doc->encoding = 'UTF-8';
- }
- return $this->doc;
- }
-
- /**
- * Sets whether images/videos/sounds should be removed from output
- * @param bool $flag
- */
- public function setRemoveMedia( $flag = true ) {
- $this->removeMedia = $flag;
- }
-
- /**
- * Adds one or more selector of content to remove. A subset of CSS selector
- * syntax is supported:
- *
- * <tag>
- * <tag>.class
- * .<class>
- * #<id>
- *
- * @param array|string $selectors Selector(s) of stuff to remove
- */
- public function remove( $selectors ) {
- $this->itemsToRemove = array_merge( $this->itemsToRemove, (array)$selectors );
- }
-
- /**
- * Adds one or more element name to the list to flatten (remove tag, but not its content)
- * Can accept undelimited regexes
- *
- * Note this interface may fail in surprising unexpected ways due to usage of regexes,
- * so should not be relied on for HTML markup security measures.
- *
- * @param array|string $elements Name(s) of tag(s) to flatten
- */
- public function flatten( $elements ) {
- $this->elementsToFlatten = array_merge( $this->elementsToFlatten, (array)$elements );
- }
-
- /**
- * Instructs the formatter to flatten all tags
- */
- public function flattenAllTags() {
- $this->flatten( '[?!]?[a-z0-9]+' );
- }
-
- /**
- * Removes content we've chosen to remove. The text of the removed elements can be
- * extracted with the getText method.
- * @return array Array of removed DOMElements
- */
- public function filterContent() {
- $removals = $this->parseItemsToRemove();
-
- // Bail out early if nothing to do
- if ( array_reduce( $removals,
- function ( $carry, $item ) {
- return $carry && !$item;
- },
- true
- ) ) {
- return array();
- }
-
- $doc = $this->getDoc();
-
- // Remove tags
-
- // You can't remove DOMNodes from a DOMNodeList as you're iterating
- // over them in a foreach loop. It will seemingly leave the internal
- // iterator on the foreach out of wack and results will be quite
- // strange. Though, making a queue of items to remove seems to work.
- $domElemsToRemove = array();
- foreach ( $removals['TAG'] as $tagToRemove ) {
- $tagToRemoveNodes = $doc->getElementsByTagName( $tagToRemove );
- foreach ( $tagToRemoveNodes as $tagToRemoveNode ) {
- if ( $tagToRemoveNode ) {
- $domElemsToRemove[] = $tagToRemoveNode;
- }
- }
- }
- $removed = $this->removeElements( $domElemsToRemove );
-
- // Elements with named IDs
- $domElemsToRemove = array();
- foreach ( $removals['ID'] as $itemToRemove ) {
- $itemToRemoveNode = $doc->getElementById( $itemToRemove );
- if ( $itemToRemoveNode ) {
- $domElemsToRemove[] = $itemToRemoveNode;
- }
- }
- $removed = array_merge( $removed, $this->removeElements( $domElemsToRemove ) );
-
- // CSS Classes
- $domElemsToRemove = array();
- $xpath = new DOMXPath( $doc );
- foreach ( $removals['CLASS'] as $classToRemove ) {
- $elements = $xpath->query( '//*[contains(@class, "' . $classToRemove . '")]' );
-
- /** @var $element DOMElement */
- foreach ( $elements as $element ) {
- $classes = $element->getAttribute( 'class' );
- if ( preg_match( "/\b$classToRemove\b/", $classes ) && $element->parentNode ) {
- $domElemsToRemove[] = $element;
- }
- }
- }
- $removed = array_merge( $removed, $this->removeElements( $domElemsToRemove ) );
-
- // Tags with CSS Classes
- foreach ( $removals['TAG_CLASS'] as $classToRemove ) {
- $parts = explode( '.', $classToRemove );
-
- $elements = $xpath->query(
- '//' . $parts[0] . '[@class="' . $parts[1] . '"]'
- );
- $removed = array_merge( $removed, $this->removeElements( $elements ) );
- }
-
- return $removed;
- }
-
- /**
- * Removes a list of elelments from DOMDocument
- * @param array|DOMNodeList $elements
- * @return array Array of removed elements
- */
- private function removeElements( $elements ) {
- $list = $elements;
- if ( $elements instanceof DOMNodeList ) {
- $list = array();
- foreach ( $elements as $element ) {
- $list[] = $element;
- }
- }
- /** @var $element DOMElement */
- foreach ( $list as $element ) {
- if ( $element->parentNode ) {
- $element->parentNode->removeChild( $element );
- }
- }
- return $list;
- }
-
- /**
- * libxml in its usual pointlessness converts many chars to entities - this function
- * perfoms a reverse conversion
- * @param string $html
- * @return string
- */
- private function fixLibXML( $html ) {
- static $replacements;
- if ( !$replacements ) {
- // We don't include rules like '"' => '&quot;' because entities had already been
- // normalized by libxml. Using this function with input not sanitized by libxml is UNSAFE!
- $replacements = new ReplacementArray( array(
- '"' => '&quot;',
- '&' => '&amp;',
- '<' => '&lt;',
- '>' => '&gt;',
- ) );
- }
- $html = $replacements->replace( $html );
-
- if ( function_exists( 'mb_convert_encoding' ) ) {
- // Just in case the conversion in getDoc() above used named
- // entities that aren't known to html_entity_decode().
- $html = mb_convert_encoding( $html, 'UTF-8', 'HTML-ENTITIES' );
- } else {
- $html = html_entity_decode( $html, ENT_COMPAT, 'utf-8' );
- }
- return $html;
- }
-
- /**
- * Performs final transformations and returns resulting HTML. Note that if you want to call this
- * both without an element and with an element you should call it without an element first. If you
- * specify the $element in the method it'll change the underlying dom and you won't be able to get
- * it back.
- *
- * @param DOMElement|string|null $element ID of element to get HTML from or
- * false to get it from the whole tree
- * @return string Processed HTML
- */
- public function getText( $element = null ) {
-
- if ( $this->doc ) {
- if ( $element !== null && !( $element instanceof DOMElement ) ) {
- $element = $this->doc->getElementById( $element );
- }
- if ( $element ) {
- $body = $this->doc->getElementsByTagName( 'body' )->item( 0 );
- $nodesArray = array();
- foreach ( $body->childNodes as $node ) {
- $nodesArray[] = $node;
- }
- foreach ( $nodesArray as $nodeArray ) {
- $body->removeChild( $nodeArray );
- }
- $body->appendChild( $element );
- }
- $html = $this->doc->saveHTML();
-
- $html = $this->fixLibXml( $html );
- if ( wfIsWindows() ) {
- // Cleanup for CRLF misprocessing of unknown origin on Windows.
- //
- // If this error continues in the future, please track it down in the
- // XML code paths if possible and fix there.
- $html = str_replace( ' ', '', $html );
- }
- } else {
- $html = $this->html;
- }
- // Remove stuff added by wrapHTML()
- $html = preg_replace( '/<!--.*?-->|^.*?<body>|<\/body>.*$/s', '', $html );
- $html = $this->onHtmlReady( $html );
-
- if ( $this->elementsToFlatten ) {
- $elements = implode( '|', $this->elementsToFlatten );
- $html = preg_replace( "#</?($elements)\\b[^>]*>#is", '', $html );
- }
-
- return $html;
- }
-
- /**
- * Helper function for parseItemsToRemove(). This function extracts the selector type
- * and the raw name of a selector from a CSS-style selector string and assigns those
- * values to parameters passed by reference. For example, if given '#toc' as the
- * $selector parameter, it will assign 'ID' as the $type and 'toc' as the $rawName.
- * @param string $selector CSS selector to parse
- * @param string $type The type of selector (ID, CLASS, TAG_CLASS, or TAG)
- * @param string $rawName The raw name of the selector
- * @return bool Whether the selector was successfully recognised
- * @throws MWException
- */
- protected function parseSelector( $selector, &$type, &$rawName ) {
- if ( strpos( $selector, '.' ) === 0 ) {
- $type = 'CLASS';
- $rawName = substr( $selector, 1 );
- } elseif ( strpos( $selector, '#' ) === 0 ) {
- $type = 'ID';
- $rawName = substr( $selector, 1 );
- } elseif ( strpos( $selector, '.' ) !== 0 && strpos( $selector, '.' ) !== false ) {
- $type = 'TAG_CLASS';
- $rawName = $selector;
- } elseif ( strpos( $selector, '[' ) === false && strpos( $selector, ']' ) === false ) {
- $type = 'TAG';
- $rawName = $selector;
- } else {
- throw new MWException( __METHOD__ . "(): unrecognized selector '$selector'" );
- }
-
- return true;
- }
-
- /**
- * Transforms CSS-style selectors into an internal representation suitable for
- * processing by filterContent()
- * @return array
- */
- protected function parseItemsToRemove() {
- $removals = array(
- 'ID' => array(),
- 'TAG' => array(),
- 'CLASS' => array(),
- 'TAG_CLASS' => array(),
- );
-
- foreach ( $this->itemsToRemove as $itemToRemove ) {
- $type = '';
- $rawName = '';
- if ( $this->parseSelector( $itemToRemove, $type, $rawName ) ) {
- $removals[$type][] = $rawName;
- }
- }
-
- if ( $this->removeMedia ) {
- $removals['TAG'][] = 'img';
- $removals['TAG'][] = 'audio';
- $removals['TAG'][] = 'video';
- }
-
- return $removals;
- }