1067 lines
No EOL
36 KiB
PHP
1067 lines
No EOL
36 KiB
PHP
<?php
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/**
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* Arc90's Readability ported to PHP for FiveFilters.org
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* Based on readability.js version 1.7.1 (without multi-page support)
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* ------------------------------------------------------
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* Original URL: http://lab.arc90.com/experiments/readability/js/readability.js
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* Arc90's project URL: http://lab.arc90.com/experiments/readability/
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* JS Source: http://code.google.com/p/arc90labs-readability
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* Ported by: Keyvan Minoukadeh, http://www.keyvan.net
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* More information: http://fivefilters.org/content-only/
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* License: Apache License, Version 2.0
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* Requires: PHP5
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* Date: 2010-10-29
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*
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* Differences between the PHP port and the original
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* ------------------------------------------------------
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* Arc90's Readability is designed to run in the browser. It works on the DOM
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* tree (the parsed HTML) after the page's CSS styles have been applied and
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* Javascript code executed. This PHP port does not run inside a browser.
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* We use PHP's ability to parse HTML to build our DOM tree, but we cannot
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* rely on CSS or Javascript support. As such, the results will not always
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* match Arc90's Readability. (For example, if a web page contains CSS style
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* rules or Javascript code which hide certain HTML elements from display,
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* Arc90's Readability will dismiss those from consideration but our PHP port,
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* unable to understand CSS or Javascript, will not know any better.)
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*
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* Another significant difference is that the aim of Arc90's Readability is
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* to re-present the main content block of a given web page so users can
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* read it more easily in their browsers. Correct identification, clean up,
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* and separation of the content block is only a part of this process.
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* This PHP port is only concerned with this part, it does not include code
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* that relates to presentation in the browser - Arc90 already do
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* that extremely well, and for PDF output there's FiveFilters.org's
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* PDF Newspaper: http://fivefilters.org/pdf-newspaper/.
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*
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* Finally, this class contains methods that might be useful for developers
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* working on HTML document fragments. So without deviating too much from
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* the original code (which I don't want to do because it makes debugging
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* and updating more difficult), I've tried to make it a little more
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* developer friendly. You should be able to use the methods here on
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* existing DOMElement objects without passing an entire HTML document to
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* be parsed.
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*/
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// This class allows us to do JavaScript like assignements to innerHTML
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require_once(dirname(__FILE__).'/JSLikeHTMLElement.php');
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// Alternative usage (for testing only!)
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// uncomment the lins below and call Readability.php in your browser
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// passing it the URL of the page you'd like content from, e.g.:
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// Readability.php?url=http://medialens.org/alerts/09/090615_the_guardian_climate.php
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/*
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if (!isset($_GET['url']) || $_GET['url'] == '') {
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die('Please pass a URL to the script. E.g. Readability.php?url=bla.com/story.html');
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}
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$url = $_GET['url'];
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if (!preg_match('!^https?://!i', $url)) $url = 'http://'.$url;
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$html = file_get_contents($url);
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$r = new Readability($html, $url);
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$r->init();
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echo $r->articleContent->innerHTML;
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*/
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class Readability
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{
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public $version = '1.7.1-without-multi-page';
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public $convertLinksToFootnotes = false;
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public $revertForcedParagraphElements = true;
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public $articleTitle;
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public $articleContent;
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public $dom;
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public $url = null; // optional - URL where HTML was retrieved
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public $debug = false;
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protected $body = null; //
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protected $bodyCache = null; // Cache the body HTML in case we need to re-use it later
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protected $flags = 7; // 1 | 2 | 4; // Start with all flags set.
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protected $success = false; // indicates whether we were able to extract or not
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/**
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* All of the regular expressions in use within readability.
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* Defined up here so we don't instantiate them repeatedly in loops.
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**/
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public $regexps = array(
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'unlikelyCandidates' => '/combx|comment|community|disqus|extra|foot|header|menu|remark|rss|shoutbox|sidebar|sponsor|ad-break|agegate|pagination|pager|popup|tweet|twitter/i',
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'okMaybeItsACandidate' => '/and|article|body|column|main|shadow/i',
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'positive' => '/article|body|content|entry|hentry|main|page|pagination|post|text|blog|story/i',
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'negative' => '/combx|comment|com-|contact|foot|footer|footnote|masthead|media|meta|outbrain|promo|related|scroll|shoutbox|sidebar|sponsor|shopping|tags|tool|widget/i',
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'divToPElements' => '/<(a|blockquote|dl|div|img|ol|p|pre|table|ul)/i',
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'replaceBrs' => '/(<br[^>]*>[ \n\r\t]*){2,}/i',
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'replaceFonts' => '/<(\/?)font[^>]*>/i',
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// 'trimRe' => '/^\s+|\s+$/g', // PHP has trim()
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'normalize' => '/\s{2,}/',
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'killBreaks' => '/(<br\s*\/?>(\s| ?)*){1,}/',
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'video' => '/http:\/\/(www\.)?(youtube|vimeo)\.com/i',
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'skipFootnoteLink' => '/^\s*(\[?[a-z0-9]{1,2}\]?|^|edit|citation needed)\s*$/i'
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);
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/* constants */
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const FLAG_STRIP_UNLIKELYS = 1;
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const FLAG_WEIGHT_CLASSES = 2;
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const FLAG_CLEAN_CONDITIONALLY = 4;
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/**
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* Create instance of Readability
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* @param string UTF-8 encoded string
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* @param string (optional) URL associated with HTML (used for footnotes)
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*/
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function __construct($html, $url=null)
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{
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/* Turn all double br's into p's */
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$html = preg_replace($this->regexps['replaceBrs'], '</p><p>', $html);
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$html = preg_replace($this->regexps['replaceFonts'], '<$1span>', $html);
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$html = mb_convert_encoding($html, 'HTML-ENTITIES', "UTF-8");
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$this->dom = new DOMDocument();
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$this->dom->preserveWhiteSpace = false;
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$this->dom->registerNodeClass('DOMElement', 'JSLikeHTMLElement');
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if (trim($html) == '') $html = '<html></html>';
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@$this->dom->loadHTML($html);
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$this->url = $url;
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}
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/**
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* Get article title element
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* @return DOMElement
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*/
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public function getTitle() {
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return $this->articleTitle;
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}
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/**
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* Get article content element
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* @return DOMElement
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*/
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public function getContent() {
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return $this->articleContent;
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}
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/**
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* Runs readability.
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*
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* Workflow:
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* 1. Prep the document by removing script tags, css, etc.
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* 2. Build readability's DOM tree.
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* 3. Grab the article content from the current dom tree.
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* 4. Replace the current DOM tree with the new one.
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* 5. Read peacefully.
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*
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* @return boolean true if we found content, false otherwise
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**/
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public function init()
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{
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$this->removeScripts($this->dom);
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//die($this->getInnerHTML($this->dom->documentElement));
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// Assume successful outcome
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$this->success = true;
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$bodyElems = $this->dom->getElementsByTagName('body');
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if ($bodyElems->length > 0) {
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if ($this->bodyCache == null) {
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$this->bodyCache = $bodyElems->item(0)->innerHTML;
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}
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if ($this->body == null) {
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$this->body = $bodyElems->item(0);
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}
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}
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$this->prepDocument();
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//die($this->dom->documentElement->parentNode->nodeType);
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//$this->setInnerHTML($this->dom->documentElement, $this->getInnerHTML($this->dom->documentElement));
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//die($this->getInnerHTML($this->dom->documentElement));
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/* Build readability's DOM tree */
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$overlay = $this->dom->createElement('div');
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$innerDiv = $this->dom->createElement('div');
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$articleTitle = $this->getArticleTitle();
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$articleContent = $this->grabArticle();
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if (!$articleContent) {
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$this->success = false;
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$articleContent = $this->dom->createElement('div');
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$articleContent->setAttribute('id', 'readability-content');
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$articleContent->innerHTML = '<p>Sorry, Readability was unable to parse this page for content.</p>';
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}
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$overlay->setAttribute('id', 'readOverlay');
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$innerDiv->setAttribute('id', 'readInner');
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/* Glue the structure of our document together. */
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$innerDiv->appendChild($articleTitle);
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$innerDiv->appendChild($articleContent);
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$overlay->appendChild($innerDiv);
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/* Clear the old HTML, insert the new content. */
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$this->body->innerHTML = '';
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$this->body->appendChild($overlay);
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//document.body.insertBefore(overlay, document.body.firstChild);
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$this->body->removeAttribute('style');
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$this->postProcessContent($articleContent);
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// Set title and content instance variables
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$this->articleTitle = $articleTitle;
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$this->articleContent = $articleContent;
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return $this->success;
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}
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/**
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* Debug
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*/
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protected function dbg($msg) {
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if ($this->debug) echo '* ',$msg, '<br />', "\n";
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}
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/**
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* Run any post-process modifications to article content as necessary.
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*
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* @param DOMElement
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* @return void
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*/
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public function postProcessContent($articleContent) {
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if ($this->convertLinksToFootnotes && !preg_match('/wikipedia\.org/', @$this->url)) {
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$this->addFootnotes($articleContent);
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}
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}
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/**
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* Get the article title as an H1.
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*
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* @return DOMElement
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*/
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protected function getArticleTitle() {
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$curTitle = '';
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$origTitle = '';
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try {
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$curTitle = $origTitle = $this->getInnerText($this->dom->getElementsByTagName('title')->item(0));
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} catch(Exception $e) {}
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if (preg_match('/ [\|\-] /', $curTitle))
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{
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$curTitle = preg_replace('/(.*)[\|\-] .*/i', '$1', $origTitle);
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if (count(explode(' ', $curTitle)) < 3) {
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$curTitle = preg_replace('/[^\|\-]*[\|\-](.*)/i', '$1', $origTitle);
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}
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}
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else if (strpos($curTitle, ': ') !== false)
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{
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$curTitle = preg_replace('/.*:(.*)/i', '$1', $origTitle);
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if (count(explode(' ', $curTitle)) < 3) {
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$curTitle = preg_replace('/[^:]*[:](.*)/i','$1', $origTitle);
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}
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}
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else if(strlen($curTitle) > 150 || strlen($curTitle) < 15)
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{
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$hOnes = $this->dom->getElementsByTagName('h1');
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if($hOnes->length == 1)
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{
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$curTitle = $this->getInnerText($hOnes->item(0));
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}
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}
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$curTitle = trim($curTitle);
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if (count(explode(' ', $curTitle)) <= 4) {
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$curTitle = $origTitle;
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}
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$articleTitle = $this->dom->createElement('h1');
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$articleTitle->innerHTML = $curTitle;
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return $articleTitle;
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}
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/**
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* Prepare the HTML document for readability to scrape it.
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* This includes things like stripping javascript, CSS, and handling terrible markup.
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*
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* @return void
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**/
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protected function prepDocument() {
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/**
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* In some cases a body element can't be found (if the HTML is totally hosed for example)
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* so we create a new body node and append it to the document.
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*/
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if ($this->body == null)
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{
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$this->body = $this->dom->createElement('body');
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$this->dom->documentElement->appendChild($this->body);
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}
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$this->body->setAttribute('id', 'readabilityBody');
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/* Remove all style tags in head */
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$styleTags = $this->dom->getElementsByTagName('style');
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for ($i = $styleTags->length-1; $i >= 0; $i--)
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{
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$styleTags->item($i)->parentNode->removeChild($styleTags->item($i));
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}
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/* Turn all double br's into p's */
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/* Note, this is pretty costly as far as processing goes. Maybe optimize later. */
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//document.body.innerHTML = document.body.innerHTML.replace(readability.regexps.replaceBrs, '</p><p>').replace(readability.regexps.replaceFonts, '<$1span>');
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// We do this in the constructor for PHP as that's when we have raw HTML - before parsing it into a DOM tree.
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// Manipulating innerHTML as it's done in JS is not possible in PHP.
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}
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/**
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* For easier reading, convert this document to have footnotes at the bottom rather than inline links.
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* @see http://www.roughtype.com/archives/2010/05/experiments_in.php
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*
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* @return void
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**/
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public function addFootnotes($articleContent) {
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$footnotesWrapper = $this->dom->createElement('div');
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$footnotesWrapper->setAttribute('id', 'readability-footnotes');
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$footnotesWrapper->innerHTML = '<h3>References</h3>';
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$articleFootnotes = $this->dom->createElement('ol');
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$articleFootnotes->setAttribute('id', 'readability-footnotes-list');
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$footnotesWrapper->appendChild($articleFootnotes);
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$articleLinks = $articleContent->getElementsByTagName('a');
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$linkCount = 0;
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for ($i = 0; $i < $articleLinks->length; $i++)
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{
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$articleLink = $articleLinks->item($i);
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$footnoteLink = $articleLink->cloneNode(true);
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$refLink = $this->dom->createElement('a');
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$footnote = $this->dom->createElement('li');
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$linkDomain = @parse_url($footnoteLink->getAttribute('href'), PHP_URL_HOST);
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if (!$linkDomain && isset($this->url)) $linkDomain = @parse_url($this->url, PHP_URL_HOST);
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//linkDomain = footnoteLink.host ? footnoteLink.host : document.location.host,
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$linkText = $this->getInnerText($articleLink);
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if ((strpos($articleLink->getAttribute('class'), 'readability-DoNotFootnote') !== false) || preg_match($this->regexps['skipFootnoteLink'], $linkText)) {
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continue;
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}
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$linkCount++;
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/** Add a superscript reference after the article link */
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$refLink->setAttribute('href', '#readabilityFootnoteLink-' . $linkCount);
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$refLink->innerHTML = '<small><sup>[' . $linkCount . ']</sup></small>';
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$refLink->setAttribute('class', 'readability-DoNotFootnote');
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$refLink->setAttribute('style', 'color: inherit;');
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//TODO: does this work or should we use DOMNode.isSameNode()?
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if ($articleLink->parentNode->lastChild == $articleLink) {
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$articleLink->parentNode->appendChild($refLink);
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} else {
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$articleLink->parentNode->insertBefore($refLink, $articleLink->nextSibling);
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}
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$articleLink->setAttribute('style', 'color: inherit; text-decoration: none;');
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$articleLink->setAttribute('name', 'readabilityLink-' . $linkCount);
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$footnote->innerHTML = '<small><sup><a href="#readabilityLink-' . $linkCount . '" title="Jump to Link in Article">^</a></sup></small> ';
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$footnoteLink->innerHTML = ($footnoteLink->getAttribute('title') != '' ? $footnoteLink->getAttribute('title') : $linkText);
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$footnoteLink->setAttribute('name', 'readabilityFootnoteLink-' . $linkCount);
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$footnote->appendChild($footnoteLink);
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if ($linkDomain) $footnote->innerHTML = $footnote->innerHTML . '<small> (' . $linkDomain . ')</small>';
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$articleFootnotes->appendChild($footnote);
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}
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if ($linkCount > 0) {
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$articleContent->appendChild($footnotesWrapper);
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}
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}
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/**
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* Reverts P elements with class 'readability-styled'
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* to text nodes - which is what they were before.
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*
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* @param DOMElement
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* @return void
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*/
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function revertReadabilityStyledElements($articleContent) {
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$xpath = new DOMXPath($articleContent->ownerDocument);
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$elems = $xpath->query('.//p[@class="readability-styled"]', $articleContent);
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//$elems = $articleContent->getElementsByTagName('p');
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for ($i = $elems->length-1; $i >= 0; $i--) {
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$e = $elems->item($i);
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$e->parentNode->replaceChild($articleContent->ownerDocument->createTextNode($e->textContent), $e);
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//if ($e->hasAttribute('class') && $e->getAttribute('class') == 'readability-styled') {
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// $e->parentNode->replaceChild($this->dom->createTextNode($e->textContent), $e);
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//}
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}
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}
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/**
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* Prepare the article node for display. Clean out any inline styles,
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* iframes, forms, strip extraneous <p> tags, etc.
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*
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* @param DOMElement
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* @return void
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*/
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function prepArticle($articleContent) {
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$this->cleanStyles($articleContent);
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$this->killBreaks($articleContent);
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if ($this->revertForcedParagraphElements) {
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$this->revertReadabilityStyledElements($articleContent);
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}
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/* Clean out junk from the article content */
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$this->cleanConditionally($articleContent, 'form');
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$this->clean($articleContent, 'object');
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$this->clean($articleContent, 'h1');
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/**
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* If there is only one h2, they are probably using it
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* as a header and not a subheader, so remove it since we already have a header.
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***/
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if ($articleContent->getElementsByTagName('h2')->length == 1) {
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$this->clean($articleContent, 'h2');
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}
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$this->clean($articleContent, 'iframe');
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$this->cleanHeaders($articleContent);
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/* Do these last as the previous stuff may have removed junk that will affect these */
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$this->cleanConditionally($articleContent, 'table');
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$this->cleanConditionally($articleContent, 'ul');
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$this->cleanConditionally($articleContent, 'div');
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/* Remove extra paragraphs */
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$articleParagraphs = $articleContent->getElementsByTagName('p');
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for ($i = $articleParagraphs->length-1; $i >= 0; $i--)
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{
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$imgCount = $articleParagraphs->item($i)->getElementsByTagName('img')->length;
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$embedCount = $articleParagraphs->item($i)->getElementsByTagName('embed')->length;
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$objectCount = $articleParagraphs->item($i)->getElementsByTagName('object')->length;
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if ($imgCount === 0 && $embedCount === 0 && $objectCount === 0 && $this->getInnerText($articleParagraphs->item($i), false) == '')
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{
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$articleParagraphs->item($i)->parentNode->removeChild($articleParagraphs->item($i));
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}
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}
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try {
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$articleContent->innerHTML = preg_replace('/<br[^>]*>\s*<p/i', '<p', $articleContent->innerHTML);
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//articleContent.innerHTML = articleContent.innerHTML.replace(/<br[^>]*>\s*<p/gi, '<p');
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}
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catch (Exception $e) {
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$this->dbg("Cleaning innerHTML of breaks failed. This is an IE strict-block-elements bug. Ignoring.: " . $e);
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}
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}
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/**
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* Initialize a node with the readability object. Also checks the
|
|
* className/id for special names to add to its score.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
protected function initializeNode($node) {
|
|
$readability = $this->dom->createAttribute('readability');
|
|
$readability->value = 0; // this is our contentScore
|
|
$node->setAttributeNode($readability);
|
|
|
|
switch (strtoupper($node->tagName)) { // unsure if strtoupper is needed, but using it just in case
|
|
case 'DIV':
|
|
$readability->value += 5;
|
|
break;
|
|
|
|
case 'PRE':
|
|
case 'TD':
|
|
case 'BLOCKQUOTE':
|
|
$readability->value += 3;
|
|
break;
|
|
|
|
case 'ADDRESS':
|
|
case 'OL':
|
|
case 'UL':
|
|
case 'DL':
|
|
case 'DD':
|
|
case 'DT':
|
|
case 'LI':
|
|
case 'FORM':
|
|
$readability->value -= 3;
|
|
break;
|
|
|
|
case 'H1':
|
|
case 'H2':
|
|
case 'H3':
|
|
case 'H4':
|
|
case 'H5':
|
|
case 'H6':
|
|
case 'TH':
|
|
$readability->value -= 5;
|
|
break;
|
|
}
|
|
$readability->value += $this->getClassWeight($node);
|
|
}
|
|
|
|
/***
|
|
* grabArticle - Using a variety of metrics (content score, classname, element types), find the content that is
|
|
* most likely to be the stuff a user wants to read. Then return it wrapped up in a div.
|
|
*
|
|
* @return DOMElement
|
|
**/
|
|
protected function grabArticle($page=null) {
|
|
$stripUnlikelyCandidates = $this->flagIsActive(self::FLAG_STRIP_UNLIKELYS);
|
|
if (!$page) $page = $this->dom;
|
|
$allElements = $page->getElementsByTagName('*');
|
|
/**
|
|
* First, node prepping. Trash nodes that look cruddy (like ones with the class name "comment", etc), and turn divs
|
|
* into P tags where they have been used inappropriately (as in, where they contain no other block level elements.)
|
|
*
|
|
* Note: Assignment from index for performance. See http://www.peachpit.com/articles/article.aspx?p=31567&seqNum=5
|
|
* TODO: Shouldn't this be a reverse traversal?
|
|
**/
|
|
$node = null;
|
|
$nodesToScore = array();
|
|
for ($nodeIndex = 0; ($node = $allElements->item($nodeIndex)); $nodeIndex++) {
|
|
//for ($nodeIndex=$targetList->length-1; $nodeIndex >= 0; $nodeIndex--) {
|
|
//$node = $targetList->item($nodeIndex);
|
|
$tagName = strtoupper($node->tagName);
|
|
/* Remove unlikely candidates */
|
|
if ($stripUnlikelyCandidates) {
|
|
$unlikelyMatchString = $node->getAttribute('class') . $node->getAttribute('id');
|
|
if (
|
|
preg_match($this->regexps['unlikelyCandidates'], $unlikelyMatchString) &&
|
|
!preg_match($this->regexps['okMaybeItsACandidate'], $unlikelyMatchString) &&
|
|
$tagName != 'BODY'
|
|
)
|
|
{
|
|
$this->dbg('Removing unlikely candidate - ' . $unlikelyMatchString);
|
|
//$nodesToRemove[] = $node;
|
|
$node->parentNode->removeChild($node);
|
|
$nodeIndex--;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if ($tagName == 'P' || $tagName == 'TD' || $tagName == 'PRE') {
|
|
$nodesToScore[] = $node;
|
|
}
|
|
|
|
/* Turn all divs that don't have children block level elements into p's */
|
|
if ($tagName == 'DIV') {
|
|
if (!preg_match($this->regexps['divToPElements'], $node->innerHTML)) {
|
|
//$this->dbg('Altering div to p');
|
|
$newNode = $this->dom->createElement('p');
|
|
try {
|
|
$newNode->innerHTML = $node->innerHTML;
|
|
//$nodesToReplace[] = array('new'=>$newNode, 'old'=>$node);
|
|
$node->parentNode->replaceChild($newNode, $node);
|
|
$nodeIndex--;
|
|
$nodesToScore[] = $node; // or $newNode?
|
|
}
|
|
catch(Exception $e) {
|
|
$this->dbg('Could not alter div to p, reverting back to div.: ' . $e);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* EXPERIMENTAL */
|
|
// TODO: change these p elements back to text nodes after processing
|
|
for ($i = 0, $il = $node->childNodes->length; $i < $il; $i++) {
|
|
$childNode = $node->childNodes->item($i);
|
|
if ($childNode->nodeType == 3) { // XML_TEXT_NODE
|
|
//$this->dbg('replacing text node with a p tag with the same content.');
|
|
$p = $this->dom->createElement('p');
|
|
$p->innerHTML = $childNode->nodeValue;
|
|
$p->setAttribute('style', 'display: inline;');
|
|
$p->setAttribute('class', 'readability-styled');
|
|
$childNode->parentNode->replaceChild($p, $childNode);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Loop through all paragraphs, and assign a score to them based on how content-y they look.
|
|
* Then add their score to their parent node.
|
|
*
|
|
* A score is determined by things like number of commas, class names, etc. Maybe eventually link density.
|
|
**/
|
|
$candidates = array();
|
|
for ($pt=0; $pt < count($nodesToScore); $pt++) {
|
|
$parentNode = $nodesToScore[$pt]->parentNode;
|
|
// $grandParentNode = $parentNode ? $parentNode->parentNode : null;
|
|
$grandParentNode = !$parentNode ? null : (($parentNode->parentNode instanceof DOMElement) ? $parentNode->parentNode : null);
|
|
$innerText = $this->getInnerText($nodesToScore[$pt]);
|
|
|
|
if (!$parentNode || !isset($parentNode->tagName)) {
|
|
continue;
|
|
}
|
|
|
|
/* If this paragraph is less than 25 characters, don't even count it. */
|
|
if(strlen($innerText) < 25) {
|
|
continue;
|
|
}
|
|
|
|
/* Initialize readability data for the parent. */
|
|
if (!$parentNode->hasAttribute('readability'))
|
|
{
|
|
$this->initializeNode($parentNode);
|
|
$candidates[] = $parentNode;
|
|
}
|
|
|
|
/* Initialize readability data for the grandparent. */
|
|
if ($grandParentNode && !$grandParentNode->hasAttribute('readability') && isset($grandParentNode->tagName))
|
|
{
|
|
$this->initializeNode($grandParentNode);
|
|
$candidates[] = $grandParentNode;
|
|
}
|
|
|
|
$contentScore = 0;
|
|
|
|
/* Add a point for the paragraph itself as a base. */
|
|
$contentScore++;
|
|
|
|
/* Add points for any commas within this paragraph */
|
|
$contentScore += count(explode(',', $innerText));
|
|
|
|
/* For every 100 characters in this paragraph, add another point. Up to 3 points. */
|
|
$contentScore += min(floor(strlen($innerText) / 100), 3);
|
|
|
|
/* Add the score to the parent. The grandparent gets half. */
|
|
$parentNode->getAttributeNode('readability')->value += $contentScore;
|
|
|
|
if ($grandParentNode) {
|
|
$grandParentNode->getAttributeNode('readability')->value += $contentScore/2;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* After we've calculated scores, loop through all of the possible candidate nodes we found
|
|
* and find the one with the highest score.
|
|
**/
|
|
$topCandidate = null;
|
|
for ($c=0, $cl=count($candidates); $c < $cl; $c++)
|
|
{
|
|
/**
|
|
* Scale the final candidates score based on link density. Good content should have a
|
|
* relatively small link density (5% or less) and be mostly unaffected by this operation.
|
|
**/
|
|
$readability = $candidates[$c]->getAttributeNode('readability');
|
|
$readability->value = $readability->value * (1-$this->getLinkDensity($candidates[$c]));
|
|
|
|
$this->dbg('Candidate: ' . $candidates[$c]->tagName . ' (' . $candidates[$c]->getAttribute('class') . ':' . $candidates[$c]->getAttribute('id') . ') with score ' . $readability->value);
|
|
|
|
if (!$topCandidate || $readability->value > (int)$topCandidate->getAttribute('readability')) {
|
|
$topCandidate = $candidates[$c];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* If we still have no top candidate, just use the body as a last resort.
|
|
* We also have to copy the body node so it is something we can modify.
|
|
**/
|
|
if ($topCandidate === null || strtoupper($topCandidate->tagName) == 'BODY')
|
|
{
|
|
$topCandidate = $this->dom->createElement('div');
|
|
$topCandidate->innerHTML = ($page instanceof DOMDocument) ? $page->saveXML($page->documentElement) : $page->innerHTML;
|
|
$page->innerHTML = '';
|
|
$page->appendChild($topCandidate);
|
|
$this->initializeNode($topCandidate);
|
|
}
|
|
|
|
/**
|
|
* Now that we have the top candidate, look through its siblings for content that might also be related.
|
|
* Things like preambles, content split by ads that we removed, etc.
|
|
**/
|
|
$articleContent = $this->dom->createElement('div');
|
|
$articleContent->setAttribute('id', 'readability-content');
|
|
$siblingScoreThreshold = max(10, ((int)$topCandidate->getAttribute('readability')) * 0.2);
|
|
$siblingNodes = $topCandidate->parentNode->childNodes;
|
|
|
|
for ($s=0, $sl=$siblingNodes->length; $s < $sl; $s++)
|
|
{
|
|
$siblingNode = $siblingNodes->item($s);
|
|
$append = false;
|
|
|
|
$this->dbg('Looking at sibling node: ' . $siblingNode->nodeName . (($siblingNode->nodeType === XML_ELEMENT_NODE && $siblingNode->hasAttribute('readability')) ? (' with score ' . $siblingNode->getAttribute('readability')) : ''));
|
|
|
|
//dbg('Sibling has score ' . ($siblingNode->readability ? siblingNode.readability.contentScore : 'Unknown'));
|
|
|
|
if ($siblingNode === $topCandidate)
|
|
// or if ($siblingNode->isSameNode($topCandidate))
|
|
{
|
|
$append = true;
|
|
}
|
|
|
|
$contentBonus = 0;
|
|
/* Give a bonus if sibling nodes and top candidates have the example same classname */
|
|
if ($siblingNode->nodeType === XML_ELEMENT_NODE && $siblingNode->getAttribute('class') == $topCandidate->getAttribute('class') && $topCandidate->getAttribute('class') != '') {
|
|
$contentBonus += ((int)$topCandidate->getAttribute('readability')) * 0.2;
|
|
}
|
|
|
|
if ($siblingNode->nodeType === XML_ELEMENT_NODE && $siblingNode->hasAttribute('readability') && (((int)$siblingNode->getAttribute('readability')) + $contentBonus) >= $siblingScoreThreshold)
|
|
{
|
|
$append = true;
|
|
}
|
|
|
|
if (strtoupper($siblingNode->nodeName) == 'P') {
|
|
$linkDensity = $this->getLinkDensity($siblingNode);
|
|
$nodeContent = $this->getInnerText($siblingNode);
|
|
$nodeLength = strlen($nodeContent);
|
|
|
|
if ($nodeLength > 80 && $linkDensity < 0.25)
|
|
{
|
|
$append = true;
|
|
}
|
|
else if ($nodeLength < 80 && $linkDensity === 0 && preg_match('/\.( |$)/', $nodeContent))
|
|
{
|
|
$append = true;
|
|
}
|
|
}
|
|
|
|
if ($append)
|
|
{
|
|
$this->dbg('Appending node: ' . $siblingNode->nodeName);
|
|
|
|
$nodeToAppend = null;
|
|
$sibNodeName = strtoupper($siblingNode->nodeName);
|
|
if ($sibNodeName != 'DIV' && $sibNodeName != 'P') {
|
|
/* We have a node that isn't a common block level element, like a form or td tag. Turn it into a div so it doesn't get filtered out later by accident. */
|
|
|
|
$this->dbg('Altering siblingNode of ' . $sibNodeName . ' to div.');
|
|
$nodeToAppend = $this->dom->createElement('div');
|
|
try {
|
|
$nodeToAppend->setAttribute('id', $siblingNode->getAttribute('id'));
|
|
$nodeToAppend->innerHTML = $siblingNode->innerHTML;
|
|
}
|
|
catch(Exception $e)
|
|
{
|
|
$this->dbg('Could not alter siblingNode to div, reverting back to original.');
|
|
$nodeToAppend = $siblingNode;
|
|
$s--;
|
|
$sl--;
|
|
}
|
|
} else {
|
|
$nodeToAppend = $siblingNode;
|
|
$s--;
|
|
$sl--;
|
|
}
|
|
|
|
/* To ensure a node does not interfere with readability styles, remove its classnames */
|
|
$nodeToAppend->removeAttribute('class');
|
|
|
|
/* Append sibling and subtract from our list because it removes the node when you append to another node */
|
|
$articleContent->appendChild($nodeToAppend);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* So we have all of the content that we need. Now we clean it up for presentation.
|
|
**/
|
|
$this->prepArticle($articleContent);
|
|
|
|
/**
|
|
* Now that we've gone through the full algorithm, check to see if we got any meaningful content.
|
|
* If we didn't, we may need to re-run grabArticle with different flags set. This gives us a higher
|
|
* likelihood of finding the content, and the sieve approach gives us a higher likelihood of
|
|
* finding the -right- content.
|
|
**/
|
|
if (strlen($this->getInnerText($articleContent, false)) < 250)
|
|
{
|
|
$this->body->innerHTML = $this->bodyCache;
|
|
|
|
if ($this->flagIsActive(self::FLAG_STRIP_UNLIKELYS)) {
|
|
$this->removeFlag(self::FLAG_STRIP_UNLIKELYS);
|
|
return $this->grabArticle($this->body);
|
|
}
|
|
else if ($this->flagIsActive(self::FLAG_WEIGHT_CLASSES)) {
|
|
$this->removeFlag(self::FLAG_WEIGHT_CLASSES);
|
|
return $this->grabArticle($this->body);
|
|
}
|
|
else if ($this->flagIsActive(self::FLAG_CLEAN_CONDITIONALLY)) {
|
|
$this->removeFlag(self::FLAG_CLEAN_CONDITIONALLY);
|
|
return $this->grabArticle($this->body);
|
|
}
|
|
else {
|
|
return false;
|
|
}
|
|
}
|
|
return $articleContent;
|
|
}
|
|
|
|
/**
|
|
* Remove script tags from document
|
|
*
|
|
* @param DOMElement
|
|
* @return void
|
|
*/
|
|
public function removeScripts($doc) {
|
|
$scripts = $doc->getElementsByTagName('script');
|
|
for($i = $scripts->length-1; $i >= 0; $i--)
|
|
{
|
|
$scripts->item($i)->parentNode->removeChild($scripts->item($i));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get the inner text of a node.
|
|
* This also strips out any excess whitespace to be found.
|
|
*
|
|
* @param DOMElement $
|
|
* @param boolean $normalizeSpaces (default: true)
|
|
* @return string
|
|
**/
|
|
public function getInnerText($e, $normalizeSpaces=true) {
|
|
$textContent = '';
|
|
|
|
if (!isset($e->textContent) || $e->textContent == '') {
|
|
return '';
|
|
}
|
|
|
|
$textContent = trim($e->textContent);
|
|
|
|
if ($normalizeSpaces) {
|
|
return preg_replace($this->regexps['normalize'], ' ', $textContent);
|
|
} else {
|
|
return $textContent;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get the number of times a string $s appears in the node $e.
|
|
*
|
|
* @param DOMElement $e
|
|
* @param string - what to count. Default is ","
|
|
* @return number (integer)
|
|
**/
|
|
public function getCharCount($e, $s=',') {
|
|
return substr_count($this->getInnerText($e), $s);
|
|
}
|
|
|
|
/**
|
|
* Remove the style attribute on every $e and under.
|
|
*
|
|
* @param DOMElement $e
|
|
* @return void
|
|
*/
|
|
public function cleanStyles($e) {
|
|
$elems = $e->getElementsByTagName('*');
|
|
foreach ($elems as $elem) {
|
|
$elem->removeAttribute('style');
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get the density of links as a percentage of the content
|
|
* This is the amount of text that is inside a link divided by the total text in the node.
|
|
*
|
|
* @param DOMElement $e
|
|
* @return number (float)
|
|
*/
|
|
public function getLinkDensity($e) {
|
|
$links = $e->getElementsByTagName('a');
|
|
$textLength = strlen($this->getInnerText($e));
|
|
$linkLength = 0;
|
|
for ($i=0, $il=$links->length; $i < $il; $i++)
|
|
{
|
|
$linkLength += strlen($this->getInnerText($links->item($i)));
|
|
}
|
|
if ($textLength > 0) {
|
|
return $linkLength / $textLength;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get an elements class/id weight. Uses regular expressions to tell if this
|
|
* element looks good or bad.
|
|
*
|
|
* @param DOMElement $e
|
|
* @return number (Integer)
|
|
*/
|
|
public function getClassWeight($e) {
|
|
if(!$this->flagIsActive(self::FLAG_WEIGHT_CLASSES)) {
|
|
return 0;
|
|
}
|
|
|
|
$weight = 0;
|
|
|
|
/* Look for a special classname */
|
|
if ($e->hasAttribute('class') && $e->getAttribute('class') != '')
|
|
{
|
|
if (preg_match($this->regexps['negative'], $e->getAttribute('class'))) {
|
|
$weight -= 25;
|
|
}
|
|
if (preg_match($this->regexps['positive'], $e->getAttribute('class'))) {
|
|
$weight += 25;
|
|
}
|
|
}
|
|
|
|
/* Look for a special ID */
|
|
if ($e->hasAttribute('id') && $e->getAttribute('id') != '')
|
|
{
|
|
if (preg_match($this->regexps['negative'], $e->getAttribute('id'))) {
|
|
$weight -= 25;
|
|
}
|
|
if (preg_match($this->regexps['positive'], $e->getAttribute('id'))) {
|
|
$weight += 25;
|
|
}
|
|
}
|
|
return $weight;
|
|
}
|
|
|
|
/**
|
|
* Remove extraneous break tags from a node.
|
|
*
|
|
* @param DOMElement $node
|
|
* @return void
|
|
*/
|
|
public function killBreaks($node) {
|
|
$html = $node->innerHTML;
|
|
$html = preg_replace($this->regexps['killBreaks'], '<br />', $html);
|
|
$node->innerHTML = $html;
|
|
}
|
|
|
|
/**
|
|
* Clean a node of all elements of type "tag".
|
|
* (Unless it's a youtube/vimeo video. People love movies.)
|
|
*
|
|
* @param DOMElement $e
|
|
* @param string $tag
|
|
* @return void
|
|
*/
|
|
public function clean($e, $tag) {
|
|
$targetList = $e->getElementsByTagName($tag);
|
|
$isEmbed = ($tag == 'object' || $tag == 'embed');
|
|
|
|
for ($y=$targetList->length-1; $y >= 0; $y--) {
|
|
/* Allow youtube and vimeo videos through as people usually want to see those. */
|
|
if ($isEmbed) {
|
|
$attributeValues = '';
|
|
for ($i=0, $il=$targetList->item($y)->attributes->length; $i < $il; $i++) {
|
|
$attributeValues .= $targetList->item($y)->attributes->item($i)->value . '|'; // DOMAttr? (TODO: test)
|
|
}
|
|
|
|
/* First, check the elements attributes to see if any of them contain youtube or vimeo */
|
|
if (preg_match($this->regexps['video'], $attributeValues)) {
|
|
continue;
|
|
}
|
|
|
|
/* Then check the elements inside this element for the same. */
|
|
if (preg_match($this->regexps['video'], $targetList->item($y)->innerHTML)) {
|
|
continue;
|
|
}
|
|
}
|
|
$targetList->item($y)->parentNode->removeChild($targetList->item($y));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Clean an element of all tags of type "tag" if they look fishy.
|
|
* "Fishy" is an algorithm based on content length, classnames,
|
|
* link density, number of images & embeds, etc.
|
|
*
|
|
* @param DOMElement $e
|
|
* @param string $tag
|
|
* @return void
|
|
*/
|
|
public function cleanConditionally($e, $tag) {
|
|
if (!$this->flagIsActive(self::FLAG_CLEAN_CONDITIONALLY)) {
|
|
return;
|
|
}
|
|
|
|
$tagsList = $e->getElementsByTagName($tag);
|
|
$curTagsLength = $tagsList->length;
|
|
|
|
/**
|
|
* Gather counts for other typical elements embedded within.
|
|
* Traverse backwards so we can remove nodes at the same time without effecting the traversal.
|
|
*
|
|
* TODO: Consider taking into account original contentScore here.
|
|
*/
|
|
for ($i=$curTagsLength-1; $i >= 0; $i--) {
|
|
$weight = $this->getClassWeight($tagsList->item($i));
|
|
$contentScore = ($tagsList->item($i)->hasAttribute('readability')) ? (int)$tagsList->item($i)->getAttribute('readability') : 0;
|
|
|
|
$this->dbg('Cleaning Conditionally ' . $tagsList->item($i)->tagName . ' (' . $tagsList->item($i)->getAttribute('class') . ':' . $tagsList->item($i)->getAttribute('id') . ')' . (($tagsList->item($i)->hasAttribute('readability')) ? (' with score ' . $tagsList->item($i)->getAttribute('readability')) : ''));
|
|
|
|
if ($weight + $contentScore < 0) {
|
|
$tagsList->item($i)->parentNode->removeChild($tagsList->item($i));
|
|
}
|
|
else if ( $this->getCharCount($tagsList->item($i), ',') < 10) {
|
|
/**
|
|
* If there are not very many commas, and the number of
|
|
* non-paragraph elements is more than paragraphs or other ominous signs, remove the element.
|
|
**/
|
|
$p = $tagsList->item($i)->getElementsByTagName('p')->length;
|
|
$img = $tagsList->item($i)->getElementsByTagName('img')->length;
|
|
$li = $tagsList->item($i)->getElementsByTagName('li')->length-100;
|
|
$input = $tagsList->item($i)->getElementsByTagName('input')->length;
|
|
|
|
$embedCount = 0;
|
|
$embeds = $tagsList->item($i)->getElementsByTagName('embed');
|
|
for ($ei=0, $il=$embeds->length; $ei < $il; $ei++) {
|
|
if (preg_match($this->regexps['video'], $embeds->item($ei)->getAttribute('src'))) {
|
|
$embedCount++;
|
|
}
|
|
}
|
|
|
|
$linkDensity = $this->getLinkDensity($tagsList->item($i));
|
|
$contentLength = strlen($this->getInnerText($tagsList->item($i)));
|
|
$toRemove = false;
|
|
|
|
if ( $img > $p ) {
|
|
$toRemove = true;
|
|
} else if ($li > $p && $tag != 'ul' && $tag != 'ol') {
|
|
$toRemove = true;
|
|
} else if ( $input > floor($p/3) ) {
|
|
$toRemove = true;
|
|
} else if ($contentLength < 25 && ($img === 0 || $img > 2) ) {
|
|
$toRemove = true;
|
|
} else if($weight < 25 && $linkDensity > 0.2) {
|
|
$toRemove = true;
|
|
} else if($weight >= 25 && $linkDensity > 0.5) {
|
|
$toRemove = true;
|
|
} else if(($embedCount == 1 && $contentLength < 75) || $embedCount > 1) {
|
|
$toRemove = true;
|
|
}
|
|
|
|
if ($toRemove) {
|
|
$tagsList->item($i)->parentNode->removeChild($tagsList->item($i));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Clean out spurious headers from an Element. Checks things like classnames and link density.
|
|
*
|
|
* @param DOMElement $e
|
|
* @return void
|
|
*/
|
|
public function cleanHeaders($e) {
|
|
for ($headerIndex = 1; $headerIndex < 3; $headerIndex++) {
|
|
$headers = $e->getElementsByTagName('h' . $headerIndex);
|
|
for ($i=$headers->length-1; $i >=0; $i--) {
|
|
if ($this->getClassWeight($headers->item($i)) < 0 || $this->getLinkDensity($headers->item($i)) > 0.33) {
|
|
$headers->item($i)->parentNode->removeChild($headers->item($i));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
public function flagIsActive($flag) {
|
|
return ($this->flags & $flag) > 0;
|
|
}
|
|
|
|
public function addFlag($flag) {
|
|
$this->flags = $this->flags | $flag;
|
|
}
|
|
|
|
public function removeFlag($flag) {
|
|
$this->flags = $this->flags & ~$flag;
|
|
}
|
|
}
|
|
?>
|