2328 lines
82 KiB
JavaScript
2328 lines
82 KiB
JavaScript
/*eslint-env es6:false*/
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/*
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* Copyright (c) 2010 Arc90 Inc
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*
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* This code is heavily based on Arc90's readability.js (1.7.1) script
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* available at: http://code.google.com/p/arc90labs-readability
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*/
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/**
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* Public constructor.
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* @param {HTMLDocument} doc The document to parse.
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* @param {Object} options The options object.
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*/
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function Readability(doc, options) {
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// In some older versions, people passed a URI as the first argument. Cope:
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if (options && options.documentElement) {
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doc = options;
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options = arguments[2];
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} else if (!doc || !doc.documentElement) {
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throw new Error("First argument to Readability constructor should be a document object.");
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}
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options = options || {};
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this._doc = doc;
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this._docJSDOMParser = this._doc.firstChild.__JSDOMParser__;
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this._articleTitle = null;
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this._articleByline = null;
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this._articleDir = null;
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this._articleSiteName = null;
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this._attempts = [];
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// Configurable options
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this._debug = !!options.debug;
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this._maxElemsToParse = options.maxElemsToParse || this.DEFAULT_MAX_ELEMS_TO_PARSE;
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this._nbTopCandidates = options.nbTopCandidates || this.DEFAULT_N_TOP_CANDIDATES;
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this._charThreshold = options.charThreshold || this.DEFAULT_CHAR_THRESHOLD;
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this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []);
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this._keepClasses = !!options.keepClasses;
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this._serializer = options.serializer || function(el) {
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return el.innerHTML;
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};
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this._disableJSONLD = !!options.disableJSONLD;
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// Start with all flags set
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this._flags = this.FLAG_STRIP_UNLIKELYS |
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this.FLAG_WEIGHT_CLASSES |
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this.FLAG_CLEAN_CONDITIONALLY;
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// Control whether log messages are sent to the console
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if (this._debug) {
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let logNode = function(node) {
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if (node.nodeType == node.TEXT_NODE) {
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return `${node.nodeName} ("${node.textContent}")`;
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}
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let attrPairs = Array.from(node.attributes || [], function(attr) {
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return `${attr.name}="${attr.value}"`;
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}).join(" ");
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return `<${node.localName} ${attrPairs}>`;
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};
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this.log = function () {
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if (typeof dump !== "undefined") {
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var msg = Array.prototype.map.call(arguments, function(x) {
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return (x && x.nodeName) ? logNode(x) : x;
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}).join(" ");
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dump("Reader: (Readability) " + msg + "\n");
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} else if (typeof console !== "undefined") {
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let args = Array.from(arguments, arg => {
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if (arg && arg.nodeType == this.ELEMENT_NODE) {
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return logNode(arg);
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}
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return arg;
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});
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args.unshift("Reader: (Readability)");
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console.log.apply(console, args);
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}
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};
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} else {
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this.log = function () {};
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}
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}
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Readability.prototype = {
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FLAG_STRIP_UNLIKELYS: 0x1,
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FLAG_WEIGHT_CLASSES: 0x2,
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FLAG_CLEAN_CONDITIONALLY: 0x4,
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// https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
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ELEMENT_NODE: 1,
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TEXT_NODE: 3,
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// Max number of nodes supported by this parser. Default: 0 (no limit)
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DEFAULT_MAX_ELEMS_TO_PARSE: 0,
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// The number of top candidates to consider when analysing how
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// tight the competition is among candidates.
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DEFAULT_N_TOP_CANDIDATES: 5,
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// Element tags to score by default.
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DEFAULT_TAGS_TO_SCORE: "section,h2,h3,h4,h5,h6,p,td,pre".toUpperCase().split(","),
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// The default number of chars an article must have in order to return a result
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DEFAULT_CHAR_THRESHOLD: 500,
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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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REGEXPS: {
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// NOTE: These two regular expressions are duplicated in
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// Readability-readerable.js. Please keep both copies in sync.
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unlikelyCandidates: /-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i,
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okMaybeItsACandidate: /and|article|body|column|content|main|shadow/i,
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positive: /article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i,
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negative: /-ad-|hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget/i,
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extraneous: /print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i,
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byline: /byline|author|dateline|writtenby|p-author/i,
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replaceFonts: /<(\/?)font[^>]*>/gi,
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normalize: /\s{2,}/g,
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videos: /\/\/(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)/i,
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shareElements: /(\b|_)(share|sharedaddy)(\b|_)/i,
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nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i,
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prevLink: /(prev|earl|old|new|<|«)/i,
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tokenize: /\W+/g,
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whitespace: /^\s*$/,
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hasContent: /\S$/,
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hashUrl: /^#.+/,
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srcsetUrl: /(\S+)(\s+[\d.]+[xw])?(\s*(?:,|$))/g,
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b64DataUrl: /^data:\s*([^\s;,]+)\s*;\s*base64\s*,/i,
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// See: https://schema.org/Article
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jsonLdArticleTypes: /^Article|AdvertiserContentArticle|NewsArticle|AnalysisNewsArticle|AskPublicNewsArticle|BackgroundNewsArticle|OpinionNewsArticle|ReportageNewsArticle|ReviewNewsArticle|Report|SatiricalArticle|ScholarlyArticle|MedicalScholarlyArticle|SocialMediaPosting|BlogPosting|LiveBlogPosting|DiscussionForumPosting|TechArticle|APIReference$/
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},
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UNLIKELY_ROLES: [ "menu", "menubar", "complementary", "navigation", "alert", "alertdialog", "dialog" ],
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DIV_TO_P_ELEMS: new Set([ "BLOCKQUOTE", "DL", "DIV", "IMG", "OL", "P", "PRE", "TABLE", "UL" ]),
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ALTER_TO_DIV_EXCEPTIONS: ["DIV", "ARTICLE", "SECTION", "P"],
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PRESENTATIONAL_ATTRIBUTES: [ "align", "background", "bgcolor", "border", "cellpadding", "cellspacing", "frame", "hspace", "rules", "style", "valign", "vspace" ],
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DEPRECATED_SIZE_ATTRIBUTE_ELEMS: [ "TABLE", "TH", "TD", "HR", "PRE" ],
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// The commented out elements qualify as phrasing content but tend to be
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// removed by readability when put into paragraphs, so we ignore them here.
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PHRASING_ELEMS: [
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// "CANVAS", "IFRAME", "SVG", "VIDEO",
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"ABBR", "AUDIO", "B", "BDO", "BR", "BUTTON", "CITE", "CODE", "DATA",
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"DATALIST", "DFN", "EM", "EMBED", "I", "IMG", "INPUT", "KBD", "LABEL",
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"MARK", "MATH", "METER", "NOSCRIPT", "OBJECT", "OUTPUT", "PROGRESS", "Q",
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"RUBY", "SAMP", "SCRIPT", "SELECT", "SMALL", "SPAN", "STRONG", "SUB",
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"SUP", "TEXTAREA", "TIME", "VAR", "WBR"
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],
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// These are the classes that readability sets itself.
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CLASSES_TO_PRESERVE: [ "page" ],
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// These are the list of HTML entities that need to be escaped.
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HTML_ESCAPE_MAP: {
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"lt": "<",
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"gt": ">",
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"amp": "&",
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"quot": '"',
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"apos": "'",
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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 Element
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* @return void
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**/
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_postProcessContent: function(articleContent) {
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// Readability cannot open relative uris so we convert them to absolute uris.
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this._fixRelativeUris(articleContent);
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this._simplifyNestedElements(articleContent);
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if (!this._keepClasses) {
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// Remove classes.
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this._cleanClasses(articleContent);
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}
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},
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/**
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* Iterates over a NodeList, calls `filterFn` for each node and removes node
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* if function returned `true`.
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*
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* If function is not passed, removes all the nodes in node list.
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*
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* @param NodeList nodeList The nodes to operate on
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* @param Function filterFn the function to use as a filter
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* @return void
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*/
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_removeNodes: function(nodeList, filterFn) {
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// Avoid ever operating on live node lists.
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if (this._docJSDOMParser && nodeList._isLiveNodeList) {
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throw new Error("Do not pass live node lists to _removeNodes");
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}
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for (var i = nodeList.length - 1; i >= 0; i--) {
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var node = nodeList[i];
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var parentNode = node.parentNode;
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if (parentNode) {
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if (!filterFn || filterFn.call(this, node, i, nodeList)) {
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parentNode.removeChild(node);
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}
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}
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}
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},
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/**
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* Iterates over a NodeList, and calls _setNodeTag for each node.
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*
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* @param NodeList nodeList The nodes to operate on
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* @param String newTagName the new tag name to use
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* @return void
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*/
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_replaceNodeTags: function(nodeList, newTagName) {
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// Avoid ever operating on live node lists.
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if (this._docJSDOMParser && nodeList._isLiveNodeList) {
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throw new Error("Do not pass live node lists to _replaceNodeTags");
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}
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for (const node of nodeList) {
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this._setNodeTag(node, newTagName);
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}
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},
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/**
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* Iterate over a NodeList, which doesn't natively fully implement the Array
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* interface.
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*
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* For convenience, the current object context is applied to the provided
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* iterate function.
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*
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* @param NodeList nodeList The NodeList.
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* @param Function fn The iterate function.
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* @return void
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*/
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_forEachNode: function(nodeList, fn) {
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Array.prototype.forEach.call(nodeList, fn, this);
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},
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/**
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* Iterate over a NodeList, and return the first node that passes
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* the supplied test function
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*
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* For convenience, the current object context is applied to the provided
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* test function.
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*
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* @param NodeList nodeList The NodeList.
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* @param Function fn The test function.
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* @return void
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*/
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_findNode: function(nodeList, fn) {
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return Array.prototype.find.call(nodeList, fn, this);
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},
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/**
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* Iterate over a NodeList, return true if any of the provided iterate
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* function calls returns true, false otherwise.
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*
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* For convenience, the current object context is applied to the
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* provided iterate function.
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*
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* @param NodeList nodeList The NodeList.
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* @param Function fn The iterate function.
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* @return Boolean
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*/
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_someNode: function(nodeList, fn) {
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return Array.prototype.some.call(nodeList, fn, this);
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},
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/**
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* Iterate over a NodeList, return true if all of the provided iterate
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* function calls return true, false otherwise.
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*
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* For convenience, the current object context is applied to the
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* provided iterate function.
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*
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* @param NodeList nodeList The NodeList.
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* @param Function fn The iterate function.
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* @return Boolean
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*/
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_everyNode: function(nodeList, fn) {
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return Array.prototype.every.call(nodeList, fn, this);
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},
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/**
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* Concat all nodelists passed as arguments.
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*
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* @return ...NodeList
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* @return Array
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*/
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_concatNodeLists: function() {
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var slice = Array.prototype.slice;
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var args = slice.call(arguments);
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var nodeLists = args.map(function(list) {
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return slice.call(list);
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});
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return Array.prototype.concat.apply([], nodeLists);
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},
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_getAllNodesWithTag: function(node, tagNames) {
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if (node.querySelectorAll) {
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return node.querySelectorAll(tagNames.join(","));
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}
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return [].concat.apply([], tagNames.map(function(tag) {
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var collection = node.getElementsByTagName(tag);
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return Array.isArray(collection) ? collection : Array.from(collection);
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}));
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},
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/**
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* Removes the class="" attribute from every element in the given
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* subtree, except those that match CLASSES_TO_PRESERVE and
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* the classesToPreserve array from the options object.
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*
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* @param Element
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* @return void
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*/
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_cleanClasses: function(node) {
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var classesToPreserve = this._classesToPreserve;
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var className = (node.getAttribute("class") || "")
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.split(/\s+/)
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.filter(function(cls) {
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return classesToPreserve.indexOf(cls) != -1;
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})
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.join(" ");
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if (className) {
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node.setAttribute("class", className);
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} else {
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node.removeAttribute("class");
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}
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for (node = node.firstElementChild; node; node = node.nextElementSibling) {
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this._cleanClasses(node);
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}
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},
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/**
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* Converts each <a> and <img> uri in the given element to an absolute URI,
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* ignoring #ref URIs.
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*
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* @param Element
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* @return void
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*/
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_fixRelativeUris: function(articleContent) {
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var baseURI = this._doc.baseURI;
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var documentURI = this._doc.documentURI;
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function toAbsoluteURI(uri) {
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// Leave hash links alone if the base URI matches the document URI:
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if (baseURI == documentURI && uri.charAt(0) == "#") {
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return uri;
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}
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// Otherwise, resolve against base URI:
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try {
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return new URL(uri, baseURI).href;
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} catch (ex) {
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// Something went wrong, just return the original:
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}
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return uri;
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}
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var links = this._getAllNodesWithTag(articleContent, ["a"]);
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this._forEachNode(links, function(link) {
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var href = link.getAttribute("href");
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if (href) {
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// Remove links with javascript: URIs, since
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// they won't work after scripts have been removed from the page.
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if (href.indexOf("javascript:") === 0) {
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// if the link only contains simple text content, it can be converted to a text node
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if (link.childNodes.length === 1 && link.childNodes[0].nodeType === this.TEXT_NODE) {
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var text = this._doc.createTextNode(link.textContent);
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link.parentNode.replaceChild(text, link);
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} else {
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// if the link has multiple children, they should all be preserved
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var container = this._doc.createElement("span");
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while (link.firstChild) {
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container.appendChild(link.firstChild);
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}
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link.parentNode.replaceChild(container, link);
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}
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} else {
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link.setAttribute("href", toAbsoluteURI(href));
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}
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}
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});
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var medias = this._getAllNodesWithTag(articleContent, [
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"img", "picture", "figure", "video", "audio", "source"
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]);
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this._forEachNode(medias, function(media) {
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var src = media.getAttribute("src");
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var poster = media.getAttribute("poster");
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var srcset = media.getAttribute("srcset");
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if (src) {
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media.setAttribute("src", toAbsoluteURI(src));
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}
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if (poster) {
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media.setAttribute("poster", toAbsoluteURI(poster));
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}
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if (srcset) {
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var newSrcset = srcset.replace(this.REGEXPS.srcsetUrl, function(_, p1, p2, p3) {
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return toAbsoluteURI(p1) + (p2 || "") + p3;
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});
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media.setAttribute("srcset", newSrcset);
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}
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});
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},
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_simplifyNestedElements: function(articleContent) {
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var node = articleContent;
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while (node) {
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if (node.parentNode && ["DIV", "SECTION"].includes(node.tagName) && !(node.id && node.id.startsWith("readability"))) {
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if (this._isElementWithoutContent(node)) {
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node = this._removeAndGetNext(node);
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continue;
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} else if (this._hasSingleTagInsideElement(node, "DIV") || this._hasSingleTagInsideElement(node, "SECTION")) {
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var child = node.children[0];
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for (var i = 0; i < node.attributes.length; i++) {
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child.setAttribute(node.attributes[i].name, node.attributes[i].value);
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}
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node.parentNode.replaceChild(child, node);
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node = child;
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continue;
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}
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}
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node = this._getNextNode(node);
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}
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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 string
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**/
|
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_getArticleTitle: function() {
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var doc = this._doc;
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var curTitle = "";
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var origTitle = "";
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try {
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curTitle = origTitle = doc.title.trim();
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// If they had an element with id "title" in their HTML
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if (typeof curTitle !== "string")
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curTitle = origTitle = this._getInnerText(doc.getElementsByTagName("title")[0]);
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} catch (e) {/* ignore exceptions setting the title. */}
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var titleHadHierarchicalSeparators = false;
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function wordCount(str) {
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return str.split(/\s+/).length;
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}
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// If there's a separator in the title, first remove the final part
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if ((/ [\|\-\\\/>»] /).test(curTitle)) {
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titleHadHierarchicalSeparators = / [\\\/>»] /.test(curTitle);
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|
curTitle = origTitle.replace(/(.*)[\|\-\\\/>»] .*/gi, "$1");
|
|
|
|
// If the resulting title is too short (3 words or fewer), remove
|
|
// the first part instead:
|
|
if (wordCount(curTitle) < 3)
|
|
curTitle = origTitle.replace(/[^\|\-\\\/>»]*[\|\-\\\/>»](.*)/gi, "$1");
|
|
} else if (curTitle.indexOf(": ") !== -1) {
|
|
// Check if we have an heading containing this exact string, so we
|
|
// could assume it's the full title.
|
|
var headings = this._concatNodeLists(
|
|
doc.getElementsByTagName("h1"),
|
|
doc.getElementsByTagName("h2")
|
|
);
|
|
var trimmedTitle = curTitle.trim();
|
|
var match = this._someNode(headings, function(heading) {
|
|
return heading.textContent.trim() === trimmedTitle;
|
|
});
|
|
|
|
// If we don't, let's extract the title out of the original title string.
|
|
if (!match) {
|
|
curTitle = origTitle.substring(origTitle.lastIndexOf(":") + 1);
|
|
|
|
// If the title is now too short, try the first colon instead:
|
|
if (wordCount(curTitle) < 3) {
|
|
curTitle = origTitle.substring(origTitle.indexOf(":") + 1);
|
|
// But if we have too many words before the colon there's something weird
|
|
// with the titles and the H tags so let's just use the original title instead
|
|
} else if (wordCount(origTitle.substr(0, origTitle.indexOf(":"))) > 5) {
|
|
curTitle = origTitle;
|
|
}
|
|
}
|
|
} else if (curTitle.length > 150 || curTitle.length < 15) {
|
|
var hOnes = doc.getElementsByTagName("h1");
|
|
|
|
if (hOnes.length === 1)
|
|
curTitle = this._getInnerText(hOnes[0]);
|
|
}
|
|
|
|
curTitle = curTitle.trim().replace(this.REGEXPS.normalize, " ");
|
|
// If we now have 4 words or fewer as our title, and either no
|
|
// 'hierarchical' separators (\, /, > or ») were found in the original
|
|
// title or we decreased the number of words by more than 1 word, use
|
|
// the original title.
|
|
var curTitleWordCount = wordCount(curTitle);
|
|
if (curTitleWordCount <= 4 &&
|
|
(!titleHadHierarchicalSeparators ||
|
|
curTitleWordCount != wordCount(origTitle.replace(/[\|\-\\\/>»]+/g, "")) - 1)) {
|
|
curTitle = origTitle;
|
|
}
|
|
|
|
return curTitle;
|
|
},
|
|
|
|
/**
|
|
* Prepare the HTML document for readability to scrape it.
|
|
* This includes things like stripping javascript, CSS, and handling terrible markup.
|
|
*
|
|
* @return void
|
|
**/
|
|
_prepDocument: function() {
|
|
var doc = this._doc;
|
|
|
|
// Remove all style tags in head
|
|
this._removeNodes(this._getAllNodesWithTag(doc, ["style"]));
|
|
|
|
if (doc.body) {
|
|
this._replaceBrs(doc.body);
|
|
}
|
|
|
|
this._replaceNodeTags(this._getAllNodesWithTag(doc, ["font"]), "SPAN");
|
|
},
|
|
|
|
/**
|
|
* Finds the next node, starting from the given node, and ignoring
|
|
* whitespace in between. If the given node is an element, the same node is
|
|
* returned.
|
|
*/
|
|
_nextNode: function (node) {
|
|
var next = node;
|
|
while (next
|
|
&& (next.nodeType != this.ELEMENT_NODE)
|
|
&& this.REGEXPS.whitespace.test(next.textContent)) {
|
|
next = next.nextSibling;
|
|
}
|
|
return next;
|
|
},
|
|
|
|
/**
|
|
* Replaces 2 or more successive <br> elements with a single <p>.
|
|
* Whitespace between <br> elements are ignored. For example:
|
|
* <div>foo<br>bar<br> <br><br>abc</div>
|
|
* will become:
|
|
* <div>foo<br>bar<p>abc</p></div>
|
|
*/
|
|
_replaceBrs: function (elem) {
|
|
this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {
|
|
var next = br.nextSibling;
|
|
|
|
// Whether 2 or more <br> elements have been found and replaced with a
|
|
// <p> block.
|
|
var replaced = false;
|
|
|
|
// If we find a <br> chain, remove the <br>s until we hit another node
|
|
// or non-whitespace. This leaves behind the first <br> in the chain
|
|
// (which will be replaced with a <p> later).
|
|
while ((next = this._nextNode(next)) && (next.tagName == "BR")) {
|
|
replaced = true;
|
|
var brSibling = next.nextSibling;
|
|
next.parentNode.removeChild(next);
|
|
next = brSibling;
|
|
}
|
|
|
|
// If we removed a <br> chain, replace the remaining <br> with a <p>. Add
|
|
// all sibling nodes as children of the <p> until we hit another <br>
|
|
// chain.
|
|
if (replaced) {
|
|
var p = this._doc.createElement("p");
|
|
br.parentNode.replaceChild(p, br);
|
|
|
|
next = p.nextSibling;
|
|
while (next) {
|
|
// If we've hit another <br><br>, we're done adding children to this <p>.
|
|
if (next.tagName == "BR") {
|
|
var nextElem = this._nextNode(next.nextSibling);
|
|
if (nextElem && nextElem.tagName == "BR")
|
|
break;
|
|
}
|
|
|
|
if (!this._isPhrasingContent(next))
|
|
break;
|
|
|
|
// Otherwise, make this node a child of the new <p>.
|
|
var sibling = next.nextSibling;
|
|
p.appendChild(next);
|
|
next = sibling;
|
|
}
|
|
|
|
while (p.lastChild && this._isWhitespace(p.lastChild)) {
|
|
p.removeChild(p.lastChild);
|
|
}
|
|
|
|
if (p.parentNode.tagName === "P")
|
|
this._setNodeTag(p.parentNode, "DIV");
|
|
}
|
|
});
|
|
},
|
|
|
|
_setNodeTag: function (node, tag) {
|
|
this.log("_setNodeTag", node, tag);
|
|
if (this._docJSDOMParser) {
|
|
node.localName = tag.toLowerCase();
|
|
node.tagName = tag.toUpperCase();
|
|
return node;
|
|
}
|
|
|
|
var replacement = node.ownerDocument.createElement(tag);
|
|
while (node.firstChild) {
|
|
replacement.appendChild(node.firstChild);
|
|
}
|
|
node.parentNode.replaceChild(replacement, node);
|
|
if (node.readability)
|
|
replacement.readability = node.readability;
|
|
|
|
for (var i = 0; i < node.attributes.length; i++) {
|
|
try {
|
|
replacement.setAttribute(node.attributes[i].name, node.attributes[i].value);
|
|
} catch (ex) {
|
|
/* it's possible for setAttribute() to throw if the attribute name
|
|
* isn't a valid XML Name. Such attributes can however be parsed from
|
|
* source in HTML docs, see https://github.com/whatwg/html/issues/4275,
|
|
* so we can hit them here and then throw. We don't care about such
|
|
* attributes so we ignore them.
|
|
*/
|
|
}
|
|
}
|
|
return replacement;
|
|
},
|
|
|
|
/**
|
|
* Prepare the article node for display. Clean out any inline styles,
|
|
* iframes, forms, strip extraneous <p> tags, etc.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
_prepArticle: function(articleContent) {
|
|
this._cleanStyles(articleContent);
|
|
|
|
// Check for data tables before we continue, to avoid removing items in
|
|
// those tables, which will often be isolated even though they're
|
|
// visually linked to other content-ful elements (text, images, etc.).
|
|
this._markDataTables(articleContent);
|
|
|
|
this._fixLazyImages(articleContent);
|
|
|
|
// Clean out junk from the article content
|
|
this._cleanConditionally(articleContent, "form");
|
|
this._cleanConditionally(articleContent, "fieldset");
|
|
this._clean(articleContent, "object");
|
|
this._clean(articleContent, "embed");
|
|
this._clean(articleContent, "footer");
|
|
this._clean(articleContent, "link");
|
|
this._clean(articleContent, "aside");
|
|
|
|
// Clean out elements with little content that have "share" in their id/class combinations from final top candidates,
|
|
// which means we don't remove the top candidates even they have "share".
|
|
|
|
var shareElementThreshold = this.DEFAULT_CHAR_THRESHOLD;
|
|
|
|
this._forEachNode(articleContent.children, function (topCandidate) {
|
|
this._cleanMatchedNodes(topCandidate, function (node, matchString) {
|
|
return this.REGEXPS.shareElements.test(matchString) && node.textContent.length < shareElementThreshold;
|
|
});
|
|
});
|
|
|
|
this._clean(articleContent, "iframe");
|
|
this._clean(articleContent, "input");
|
|
this._clean(articleContent, "textarea");
|
|
this._clean(articleContent, "select");
|
|
this._clean(articleContent, "button");
|
|
this._cleanHeaders(articleContent);
|
|
|
|
// Do these last as the previous stuff may have removed junk
|
|
// that will affect these
|
|
this._cleanConditionally(articleContent, "table");
|
|
this._cleanConditionally(articleContent, "ul");
|
|
this._cleanConditionally(articleContent, "div");
|
|
|
|
// replace H1 with H2 as H1 should be only title that is displayed separately
|
|
this._replaceNodeTags(this._getAllNodesWithTag(articleContent, ["h1"]), "h2");
|
|
|
|
// Remove extra paragraphs
|
|
this._removeNodes(this._getAllNodesWithTag(articleContent, ["p"]), function (paragraph) {
|
|
var imgCount = paragraph.getElementsByTagName("img").length;
|
|
var embedCount = paragraph.getElementsByTagName("embed").length;
|
|
var objectCount = paragraph.getElementsByTagName("object").length;
|
|
// At this point, nasty iframes have been removed, only remain embedded video ones.
|
|
var iframeCount = paragraph.getElementsByTagName("iframe").length;
|
|
var totalCount = imgCount + embedCount + objectCount + iframeCount;
|
|
|
|
return totalCount === 0 && !this._getInnerText(paragraph, false);
|
|
});
|
|
|
|
this._forEachNode(this._getAllNodesWithTag(articleContent, ["br"]), function(br) {
|
|
var next = this._nextNode(br.nextSibling);
|
|
if (next && next.tagName == "P")
|
|
br.parentNode.removeChild(br);
|
|
});
|
|
|
|
// Remove single-cell tables
|
|
this._forEachNode(this._getAllNodesWithTag(articleContent, ["table"]), function(table) {
|
|
var tbody = this._hasSingleTagInsideElement(table, "TBODY") ? table.firstElementChild : table;
|
|
if (this._hasSingleTagInsideElement(tbody, "TR")) {
|
|
var row = tbody.firstElementChild;
|
|
if (this._hasSingleTagInsideElement(row, "TD")) {
|
|
var cell = row.firstElementChild;
|
|
cell = this._setNodeTag(cell, this._everyNode(cell.childNodes, this._isPhrasingContent) ? "P" : "DIV");
|
|
table.parentNode.replaceChild(cell, table);
|
|
}
|
|
}
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Initialize a node with the readability object. Also checks the
|
|
* className/id for special names to add to its score.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
_initializeNode: function(node) {
|
|
node.readability = {"contentScore": 0};
|
|
|
|
switch (node.tagName) {
|
|
case "DIV":
|
|
node.readability.contentScore += 5;
|
|
break;
|
|
|
|
case "PRE":
|
|
case "TD":
|
|
case "BLOCKQUOTE":
|
|
node.readability.contentScore += 3;
|
|
break;
|
|
|
|
case "ADDRESS":
|
|
case "OL":
|
|
case "UL":
|
|
case "DL":
|
|
case "DD":
|
|
case "DT":
|
|
case "LI":
|
|
case "FORM":
|
|
node.readability.contentScore -= 3;
|
|
break;
|
|
|
|
case "H1":
|
|
case "H2":
|
|
case "H3":
|
|
case "H4":
|
|
case "H5":
|
|
case "H6":
|
|
case "TH":
|
|
node.readability.contentScore -= 5;
|
|
break;
|
|
}
|
|
|
|
node.readability.contentScore += this._getClassWeight(node);
|
|
},
|
|
|
|
_removeAndGetNext: function(node) {
|
|
var nextNode = this._getNextNode(node, true);
|
|
node.parentNode.removeChild(node);
|
|
return nextNode;
|
|
},
|
|
|
|
/**
|
|
* Traverse the DOM from node to node, starting at the node passed in.
|
|
* Pass true for the second parameter to indicate this node itself
|
|
* (and its kids) are going away, and we want the next node over.
|
|
*
|
|
* Calling this in a loop will traverse the DOM depth-first.
|
|
*/
|
|
_getNextNode: function(node, ignoreSelfAndKids) {
|
|
// First check for kids if those aren't being ignored
|
|
if (!ignoreSelfAndKids && node.firstElementChild) {
|
|
return node.firstElementChild;
|
|
}
|
|
// Then for siblings...
|
|
if (node.nextElementSibling) {
|
|
return node.nextElementSibling;
|
|
}
|
|
// And finally, move up the parent chain *and* find a sibling
|
|
// (because this is depth-first traversal, we will have already
|
|
// seen the parent nodes themselves).
|
|
do {
|
|
node = node.parentNode;
|
|
} while (node && !node.nextElementSibling);
|
|
return node && node.nextElementSibling;
|
|
},
|
|
|
|
// compares second text to first one
|
|
// 1 = same text, 0 = completely different text
|
|
// works the way that it splits both texts into words and then finds words that are unique in second text
|
|
// the result is given by the lower length of unique parts
|
|
_textSimilarity: function(textA, textB) {
|
|
var tokensA = textA.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
|
|
var tokensB = textB.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
|
|
if (!tokensA.length || !tokensB.length) {
|
|
return 0;
|
|
}
|
|
var uniqTokensB = tokensB.filter(token => !tokensA.includes(token));
|
|
var distanceB = uniqTokensB.join(" ").length / tokensB.join(" ").length;
|
|
return 1 - distanceB;
|
|
},
|
|
|
|
_checkByline: function(node, matchString) {
|
|
if (this._articleByline) {
|
|
return false;
|
|
}
|
|
|
|
if (node.getAttribute !== undefined) {
|
|
var rel = node.getAttribute("rel");
|
|
var itemprop = node.getAttribute("itemprop");
|
|
}
|
|
|
|
if ((rel === "author" || (itemprop && itemprop.indexOf("author") !== -1) || this.REGEXPS.byline.test(matchString)) && this._isValidByline(node.textContent)) {
|
|
this._articleByline = node.textContent.trim();
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
},
|
|
|
|
_getNodeAncestors: function(node, maxDepth) {
|
|
maxDepth = maxDepth || 0;
|
|
var i = 0, ancestors = [];
|
|
while (node.parentNode) {
|
|
ancestors.push(node.parentNode);
|
|
if (maxDepth && ++i === maxDepth)
|
|
break;
|
|
node = node.parentNode;
|
|
}
|
|
return ancestors;
|
|
},
|
|
|
|
/***
|
|
* 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.
|
|
*
|
|
* @param page a document to run upon. Needs to be a full document, complete with body.
|
|
* @return Element
|
|
**/
|
|
_grabArticle: function (page) {
|
|
this.log("**** grabArticle ****");
|
|
var doc = this._doc;
|
|
var isPaging = page !== null;
|
|
page = page ? page : this._doc.body;
|
|
|
|
// We can't grab an article if we don't have a page!
|
|
if (!page) {
|
|
this.log("No body found in document. Abort.");
|
|
return null;
|
|
}
|
|
|
|
var pageCacheHtml = page.innerHTML;
|
|
|
|
while (true) {
|
|
this.log("Starting grabArticle loop");
|
|
var stripUnlikelyCandidates = this._flagIsActive(this.FLAG_STRIP_UNLIKELYS);
|
|
|
|
// 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.)
|
|
var elementsToScore = [];
|
|
var node = this._doc.documentElement;
|
|
|
|
let shouldRemoveTitleHeader = true;
|
|
|
|
while (node) {
|
|
|
|
if (node.tagName === "HTML") {
|
|
this._articleLang = node.getAttribute("lang");
|
|
}
|
|
|
|
var matchString = node.className + " " + node.id;
|
|
|
|
if (!this._isProbablyVisible(node)) {
|
|
this.log("Removing hidden node - " + matchString);
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
|
|
// Check to see if this node is a byline, and remove it if it is.
|
|
if (this._checkByline(node, matchString)) {
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
|
|
if (shouldRemoveTitleHeader && this._headerDuplicatesTitle(node)) {
|
|
this.log("Removing header: ", node.textContent.trim(), this._articleTitle.trim());
|
|
shouldRemoveTitleHeader = false;
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
|
|
// Remove unlikely candidates
|
|
if (stripUnlikelyCandidates) {
|
|
if (this.REGEXPS.unlikelyCandidates.test(matchString) &&
|
|
!this.REGEXPS.okMaybeItsACandidate.test(matchString) &&
|
|
!this._hasAncestorTag(node, "table") &&
|
|
!this._hasAncestorTag(node, "code") &&
|
|
node.tagName !== "BODY" &&
|
|
node.tagName !== "A") {
|
|
this.log("Removing unlikely candidate - " + matchString);
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
|
|
if (this.UNLIKELY_ROLES.includes(node.getAttribute("role"))) {
|
|
this.log("Removing content with role " + node.getAttribute("role") + " - " + matchString);
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Remove DIV, SECTION, and HEADER nodes without any content(e.g. text, image, video, or iframe).
|
|
if ((node.tagName === "DIV" || node.tagName === "SECTION" || node.tagName === "HEADER" ||
|
|
node.tagName === "H1" || node.tagName === "H2" || node.tagName === "H3" ||
|
|
node.tagName === "H4" || node.tagName === "H5" || node.tagName === "H6") &&
|
|
this._isElementWithoutContent(node)) {
|
|
node = this._removeAndGetNext(node);
|
|
continue;
|
|
}
|
|
|
|
if (this.DEFAULT_TAGS_TO_SCORE.indexOf(node.tagName) !== -1) {
|
|
elementsToScore.push(node);
|
|
}
|
|
|
|
// Turn all divs that don't have children block level elements into p's
|
|
if (node.tagName === "DIV") {
|
|
// Put phrasing content into paragraphs.
|
|
var p = null;
|
|
var childNode = node.firstChild;
|
|
while (childNode) {
|
|
var nextSibling = childNode.nextSibling;
|
|
if (this._isPhrasingContent(childNode)) {
|
|
if (p !== null) {
|
|
p.appendChild(childNode);
|
|
} else if (!this._isWhitespace(childNode)) {
|
|
p = doc.createElement("p");
|
|
node.replaceChild(p, childNode);
|
|
p.appendChild(childNode);
|
|
}
|
|
} else if (p !== null) {
|
|
while (p.lastChild && this._isWhitespace(p.lastChild)) {
|
|
p.removeChild(p.lastChild);
|
|
}
|
|
p = null;
|
|
}
|
|
childNode = nextSibling;
|
|
}
|
|
|
|
// Sites like http://mobile.slate.com encloses each paragraph with a DIV
|
|
// element. DIVs with only a P element inside and no text content can be
|
|
// safely converted into plain P elements to avoid confusing the scoring
|
|
// algorithm with DIVs with are, in practice, paragraphs.
|
|
if (this._hasSingleTagInsideElement(node, "P") && this._getLinkDensity(node) < 0.25) {
|
|
var newNode = node.children[0];
|
|
node.parentNode.replaceChild(newNode, node);
|
|
node = newNode;
|
|
elementsToScore.push(node);
|
|
} else if (!this._hasChildBlockElement(node)) {
|
|
node = this._setNodeTag(node, "P");
|
|
elementsToScore.push(node);
|
|
}
|
|
}
|
|
node = this._getNextNode(node);
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
**/
|
|
var candidates = [];
|
|
this._forEachNode(elementsToScore, function(elementToScore) {
|
|
if (!elementToScore.parentNode || typeof(elementToScore.parentNode.tagName) === "undefined")
|
|
return;
|
|
|
|
// If this paragraph is less than 25 characters, don't even count it.
|
|
var innerText = this._getInnerText(elementToScore);
|
|
if (innerText.length < 25)
|
|
return;
|
|
|
|
// Exclude nodes with no ancestor.
|
|
var ancestors = this._getNodeAncestors(elementToScore, 5);
|
|
if (ancestors.length === 0)
|
|
return;
|
|
|
|
var contentScore = 0;
|
|
|
|
// Add a point for the paragraph itself as a base.
|
|
contentScore += 1;
|
|
|
|
// Add points for any commas within this paragraph.
|
|
contentScore += innerText.split(",").length;
|
|
|
|
// For every 100 characters in this paragraph, add another point. Up to 3 points.
|
|
contentScore += Math.min(Math.floor(innerText.length / 100), 3);
|
|
|
|
// Initialize and score ancestors.
|
|
this._forEachNode(ancestors, function(ancestor, level) {
|
|
if (!ancestor.tagName || !ancestor.parentNode || typeof(ancestor.parentNode.tagName) === "undefined")
|
|
return;
|
|
|
|
if (typeof(ancestor.readability) === "undefined") {
|
|
this._initializeNode(ancestor);
|
|
candidates.push(ancestor);
|
|
}
|
|
|
|
// Node score divider:
|
|
// - parent: 1 (no division)
|
|
// - grandparent: 2
|
|
// - great grandparent+: ancestor level * 3
|
|
if (level === 0)
|
|
var scoreDivider = 1;
|
|
else if (level === 1)
|
|
scoreDivider = 2;
|
|
else
|
|
scoreDivider = level * 3;
|
|
ancestor.readability.contentScore += contentScore / scoreDivider;
|
|
});
|
|
});
|
|
|
|
// After we've calculated scores, loop through all of the possible
|
|
// candidate nodes we found and find the one with the highest score.
|
|
var topCandidates = [];
|
|
for (var c = 0, cl = candidates.length; c < cl; c += 1) {
|
|
var candidate = candidates[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.
|
|
var candidateScore = candidate.readability.contentScore * (1 - this._getLinkDensity(candidate));
|
|
candidate.readability.contentScore = candidateScore;
|
|
|
|
this.log("Candidate:", candidate, "with score " + candidateScore);
|
|
|
|
for (var t = 0; t < this._nbTopCandidates; t++) {
|
|
var aTopCandidate = topCandidates[t];
|
|
|
|
if (!aTopCandidate || candidateScore > aTopCandidate.readability.contentScore) {
|
|
topCandidates.splice(t, 0, candidate);
|
|
if (topCandidates.length > this._nbTopCandidates)
|
|
topCandidates.pop();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
var topCandidate = topCandidates[0] || null;
|
|
var neededToCreateTopCandidate = false;
|
|
var parentOfTopCandidate;
|
|
|
|
// 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 || topCandidate.tagName === "BODY") {
|
|
// Move all of the page's children into topCandidate
|
|
topCandidate = doc.createElement("DIV");
|
|
neededToCreateTopCandidate = true;
|
|
// Move everything (not just elements, also text nodes etc.) into the container
|
|
// so we even include text directly in the body:
|
|
while (page.firstChild) {
|
|
this.log("Moving child out:", page.firstChild);
|
|
topCandidate.appendChild(page.firstChild);
|
|
}
|
|
|
|
page.appendChild(topCandidate);
|
|
|
|
this._initializeNode(topCandidate);
|
|
} else if (topCandidate) {
|
|
// Find a better top candidate node if it contains (at least three) nodes which belong to `topCandidates` array
|
|
// and whose scores are quite closed with current `topCandidate` node.
|
|
var alternativeCandidateAncestors = [];
|
|
for (var i = 1; i < topCandidates.length; i++) {
|
|
if (topCandidates[i].readability.contentScore / topCandidate.readability.contentScore >= 0.75) {
|
|
alternativeCandidateAncestors.push(this._getNodeAncestors(topCandidates[i]));
|
|
}
|
|
}
|
|
var MINIMUM_TOPCANDIDATES = 3;
|
|
if (alternativeCandidateAncestors.length >= MINIMUM_TOPCANDIDATES) {
|
|
parentOfTopCandidate = topCandidate.parentNode;
|
|
while (parentOfTopCandidate.tagName !== "BODY") {
|
|
var listsContainingThisAncestor = 0;
|
|
for (var ancestorIndex = 0; ancestorIndex < alternativeCandidateAncestors.length && listsContainingThisAncestor < MINIMUM_TOPCANDIDATES; ancestorIndex++) {
|
|
listsContainingThisAncestor += Number(alternativeCandidateAncestors[ancestorIndex].includes(parentOfTopCandidate));
|
|
}
|
|
if (listsContainingThisAncestor >= MINIMUM_TOPCANDIDATES) {
|
|
topCandidate = parentOfTopCandidate;
|
|
break;
|
|
}
|
|
parentOfTopCandidate = parentOfTopCandidate.parentNode;
|
|
}
|
|
}
|
|
if (!topCandidate.readability) {
|
|
this._initializeNode(topCandidate);
|
|
}
|
|
|
|
// Because of our bonus system, parents of candidates might have scores
|
|
// themselves. They get half of the node. There won't be nodes with higher
|
|
// scores than our topCandidate, but if we see the score going *up* in the first
|
|
// few steps up the tree, that's a decent sign that there might be more content
|
|
// lurking in other places that we want to unify in. The sibling stuff
|
|
// below does some of that - but only if we've looked high enough up the DOM
|
|
// tree.
|
|
parentOfTopCandidate = topCandidate.parentNode;
|
|
var lastScore = topCandidate.readability.contentScore;
|
|
// The scores shouldn't get too low.
|
|
var scoreThreshold = lastScore / 3;
|
|
while (parentOfTopCandidate.tagName !== "BODY") {
|
|
if (!parentOfTopCandidate.readability) {
|
|
parentOfTopCandidate = parentOfTopCandidate.parentNode;
|
|
continue;
|
|
}
|
|
var parentScore = parentOfTopCandidate.readability.contentScore;
|
|
if (parentScore < scoreThreshold)
|
|
break;
|
|
if (parentScore > lastScore) {
|
|
// Alright! We found a better parent to use.
|
|
topCandidate = parentOfTopCandidate;
|
|
break;
|
|
}
|
|
lastScore = parentOfTopCandidate.readability.contentScore;
|
|
parentOfTopCandidate = parentOfTopCandidate.parentNode;
|
|
}
|
|
|
|
// If the top candidate is the only child, use parent instead. This will help sibling
|
|
// joining logic when adjacent content is actually located in parent's sibling node.
|
|
parentOfTopCandidate = topCandidate.parentNode;
|
|
while (parentOfTopCandidate.tagName != "BODY" && parentOfTopCandidate.children.length == 1) {
|
|
topCandidate = parentOfTopCandidate;
|
|
parentOfTopCandidate = topCandidate.parentNode;
|
|
}
|
|
if (!topCandidate.readability) {
|
|
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.
|
|
var articleContent = doc.createElement("DIV");
|
|
if (isPaging)
|
|
articleContent.id = "readability-content";
|
|
|
|
var siblingScoreThreshold = Math.max(10, topCandidate.readability.contentScore * 0.2);
|
|
// Keep potential top candidate's parent node to try to get text direction of it later.
|
|
parentOfTopCandidate = topCandidate.parentNode;
|
|
var siblings = parentOfTopCandidate.children;
|
|
|
|
for (var s = 0, sl = siblings.length; s < sl; s++) {
|
|
var sibling = siblings[s];
|
|
var append = false;
|
|
|
|
this.log("Looking at sibling node:", sibling, sibling.readability ? ("with score " + sibling.readability.contentScore) : "");
|
|
this.log("Sibling has score", sibling.readability ? sibling.readability.contentScore : "Unknown");
|
|
|
|
if (sibling === topCandidate) {
|
|
append = true;
|
|
} else {
|
|
var contentBonus = 0;
|
|
|
|
// Give a bonus if sibling nodes and top candidates have the example same classname
|
|
if (sibling.className === topCandidate.className && topCandidate.className !== "")
|
|
contentBonus += topCandidate.readability.contentScore * 0.2;
|
|
|
|
if (sibling.readability &&
|
|
((sibling.readability.contentScore + contentBonus) >= siblingScoreThreshold)) {
|
|
append = true;
|
|
} else if (sibling.nodeName === "P") {
|
|
var linkDensity = this._getLinkDensity(sibling);
|
|
var nodeContent = this._getInnerText(sibling);
|
|
var nodeLength = nodeContent.length;
|
|
|
|
if (nodeLength > 80 && linkDensity < 0.25) {
|
|
append = true;
|
|
} else if (nodeLength < 80 && nodeLength > 0 && linkDensity === 0 &&
|
|
nodeContent.search(/\.( |$)/) !== -1) {
|
|
append = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (append) {
|
|
this.log("Appending node:", sibling);
|
|
|
|
if (this.ALTER_TO_DIV_EXCEPTIONS.indexOf(sibling.nodeName) === -1) {
|
|
// 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.log("Altering sibling:", sibling, "to div.");
|
|
|
|
sibling = this._setNodeTag(sibling, "DIV");
|
|
}
|
|
|
|
articleContent.appendChild(sibling);
|
|
// Fetch children again to make it compatible
|
|
// with DOM parsers without live collection support.
|
|
siblings = parentOfTopCandidate.children;
|
|
// siblings is a reference to the children array, and
|
|
// sibling is removed from the array when we call appendChild().
|
|
// As a result, we must revisit this index since the nodes
|
|
// have been shifted.
|
|
s -= 1;
|
|
sl -= 1;
|
|
}
|
|
}
|
|
|
|
if (this._debug)
|
|
this.log("Article content pre-prep: " + articleContent.innerHTML);
|
|
// So we have all of the content that we need. Now we clean it up for presentation.
|
|
this._prepArticle(articleContent);
|
|
if (this._debug)
|
|
this.log("Article content post-prep: " + articleContent.innerHTML);
|
|
|
|
if (neededToCreateTopCandidate) {
|
|
// We already created a fake div thing, and there wouldn't have been any siblings left
|
|
// for the previous loop, so there's no point trying to create a new div, and then
|
|
// move all the children over. Just assign IDs and class names here. No need to append
|
|
// because that already happened anyway.
|
|
topCandidate.id = "readability-page-1";
|
|
topCandidate.className = "page";
|
|
} else {
|
|
var div = doc.createElement("DIV");
|
|
div.id = "readability-page-1";
|
|
div.className = "page";
|
|
while (articleContent.firstChild) {
|
|
div.appendChild(articleContent.firstChild);
|
|
}
|
|
articleContent.appendChild(div);
|
|
}
|
|
|
|
if (this._debug)
|
|
this.log("Article content after paging: " + articleContent.innerHTML);
|
|
|
|
var parseSuccessful = true;
|
|
|
|
// 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.
|
|
var textLength = this._getInnerText(articleContent, true).length;
|
|
if (textLength < this._charThreshold) {
|
|
parseSuccessful = false;
|
|
page.innerHTML = pageCacheHtml;
|
|
|
|
if (this._flagIsActive(this.FLAG_STRIP_UNLIKELYS)) {
|
|
this._removeFlag(this.FLAG_STRIP_UNLIKELYS);
|
|
this._attempts.push({articleContent: articleContent, textLength: textLength});
|
|
} else if (this._flagIsActive(this.FLAG_WEIGHT_CLASSES)) {
|
|
this._removeFlag(this.FLAG_WEIGHT_CLASSES);
|
|
this._attempts.push({articleContent: articleContent, textLength: textLength});
|
|
} else if (this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY)) {
|
|
this._removeFlag(this.FLAG_CLEAN_CONDITIONALLY);
|
|
this._attempts.push({articleContent: articleContent, textLength: textLength});
|
|
} else {
|
|
this._attempts.push({articleContent: articleContent, textLength: textLength});
|
|
// No luck after removing flags, just return the longest text we found during the different loops
|
|
this._attempts.sort(function (a, b) {
|
|
return b.textLength - a.textLength;
|
|
});
|
|
|
|
// But first check if we actually have something
|
|
if (!this._attempts[0].textLength) {
|
|
return null;
|
|
}
|
|
|
|
articleContent = this._attempts[0].articleContent;
|
|
parseSuccessful = true;
|
|
}
|
|
}
|
|
|
|
if (parseSuccessful) {
|
|
// Find out text direction from ancestors of final top candidate.
|
|
var ancestors = [parentOfTopCandidate, topCandidate].concat(this._getNodeAncestors(parentOfTopCandidate));
|
|
this._someNode(ancestors, function(ancestor) {
|
|
if (!ancestor.tagName)
|
|
return false;
|
|
var articleDir = ancestor.getAttribute("dir");
|
|
if (articleDir) {
|
|
this._articleDir = articleDir;
|
|
return true;
|
|
}
|
|
return false;
|
|
});
|
|
return articleContent;
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Check whether the input string could be a byline.
|
|
* This verifies that the input is a string, and that the length
|
|
* is less than 100 chars.
|
|
*
|
|
* @param possibleByline {string} - a string to check whether its a byline.
|
|
* @return Boolean - whether the input string is a byline.
|
|
*/
|
|
_isValidByline: function(byline) {
|
|
if (typeof byline == "string" || byline instanceof String) {
|
|
byline = byline.trim();
|
|
return (byline.length > 0) && (byline.length < 100);
|
|
}
|
|
return false;
|
|
},
|
|
|
|
/**
|
|
* Converts some of the common HTML entities in string to their corresponding characters.
|
|
*
|
|
* @param str {string} - a string to unescape.
|
|
* @return string without HTML entity.
|
|
*/
|
|
_unescapeHtmlEntities: function(str) {
|
|
if (!str) {
|
|
return str;
|
|
}
|
|
|
|
var htmlEscapeMap = this.HTML_ESCAPE_MAP;
|
|
return str.replace(/&(quot|amp|apos|lt|gt);/g, function(_, tag) {
|
|
return htmlEscapeMap[tag];
|
|
}).replace(/&#(?:x([0-9a-z]{1,4})|([0-9]{1,4}));/gi, function(_, hex, numStr) {
|
|
var num = parseInt(hex || numStr, hex ? 16 : 10);
|
|
return String.fromCharCode(num);
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Try to extract metadata from JSON-LD object.
|
|
* For now, only Schema.org objects of type Article or its subtypes are supported.
|
|
* @return Object with any metadata that could be extracted (possibly none)
|
|
*/
|
|
_getJSONLD: function (doc) {
|
|
var scripts = this._getAllNodesWithTag(doc, ["script"]);
|
|
|
|
var metadata;
|
|
|
|
this._forEachNode(scripts, function(jsonLdElement) {
|
|
if (!metadata && jsonLdElement.getAttribute("type") === "application/ld+json") {
|
|
try {
|
|
// Strip CDATA markers if present
|
|
var content = jsonLdElement.textContent.replace(/^\s*<!\[CDATA\[|\]\]>\s*$/g, "");
|
|
var parsed = JSON.parse(content);
|
|
if (
|
|
!parsed["@context"] ||
|
|
!parsed["@context"].match(/^https?\:\/\/schema\.org$/)
|
|
) {
|
|
return;
|
|
}
|
|
|
|
if (!parsed["@type"] && Array.isArray(parsed["@graph"])) {
|
|
parsed = parsed["@graph"].find(function(it) {
|
|
return (it["@type"] || "").match(
|
|
this.REGEXPS.jsonLdArticleTypes
|
|
);
|
|
});
|
|
}
|
|
|
|
if (
|
|
!parsed ||
|
|
!parsed["@type"] ||
|
|
!parsed["@type"].match(this.REGEXPS.jsonLdArticleTypes)
|
|
) {
|
|
return;
|
|
}
|
|
|
|
metadata = {};
|
|
|
|
if (typeof parsed.name === "string" && typeof parsed.headline === "string" && parsed.name !== parsed.headline) {
|
|
// we have both name and headline element in the JSON-LD. They should both be the same but some websites like aktualne.cz
|
|
// put their own name into "name" and the article title to "headline" which confuses Readability. So we try to check if either
|
|
// "name" or "headline" closely matches the html title, and if so, use that one. If not, then we use "name" by default.
|
|
|
|
var title = this._getArticleTitle();
|
|
var nameMatches = this._textSimilarity(parsed.name, title) > 0.75;
|
|
var headlineMatches = this._textSimilarity(parsed.headline, title) > 0.75;
|
|
|
|
if (headlineMatches && !nameMatches) {
|
|
metadata.title = parsed.headline;
|
|
} else {
|
|
metadata.title = parsed.name;
|
|
}
|
|
} else if (typeof parsed.name === "string") {
|
|
metadata.title = parsed.name.trim();
|
|
} else if (typeof parsed.headline === "string") {
|
|
metadata.title = parsed.headline.trim();
|
|
}
|
|
if (parsed.author) {
|
|
if (typeof parsed.author.name === "string") {
|
|
metadata.byline = parsed.author.name.trim();
|
|
} else if (Array.isArray(parsed.author) && parsed.author[0] && typeof parsed.author[0].name === "string") {
|
|
metadata.byline = parsed.author
|
|
.filter(function(author) {
|
|
return author && typeof author.name === "string";
|
|
})
|
|
.map(function(author) {
|
|
return author.name.trim();
|
|
})
|
|
.join(", ");
|
|
}
|
|
}
|
|
if (typeof parsed.description === "string") {
|
|
metadata.excerpt = parsed.description.trim();
|
|
}
|
|
if (
|
|
parsed.publisher &&
|
|
typeof parsed.publisher.name === "string"
|
|
) {
|
|
metadata.siteName = parsed.publisher.name.trim();
|
|
}
|
|
return;
|
|
} catch (err) {
|
|
this.log(err.message);
|
|
}
|
|
}
|
|
});
|
|
return metadata ? metadata : {};
|
|
},
|
|
|
|
/**
|
|
* Attempts to get excerpt and byline metadata for the article.
|
|
*
|
|
* @param {Object} jsonld — object containing any metadata that
|
|
* could be extracted from JSON-LD object.
|
|
*
|
|
* @return Object with optional "excerpt" and "byline" properties
|
|
*/
|
|
_getArticleMetadata: function(jsonld) {
|
|
var metadata = {};
|
|
var values = {};
|
|
var metaElements = this._doc.getElementsByTagName("meta");
|
|
|
|
// property is a space-separated list of values
|
|
var propertyPattern = /\s*(dc|dcterm|og|twitter)\s*:\s*(author|creator|description|title|site_name)\s*/gi;
|
|
|
|
// name is a single value
|
|
var namePattern = /^\s*(?:(dc|dcterm|og|twitter|weibo:(article|webpage))\s*[\.:]\s*)?(author|creator|description|title|site_name)\s*$/i;
|
|
|
|
// Find description tags.
|
|
this._forEachNode(metaElements, function(element) {
|
|
var elementName = element.getAttribute("name");
|
|
var elementProperty = element.getAttribute("property");
|
|
var content = element.getAttribute("content");
|
|
if (!content) {
|
|
return;
|
|
}
|
|
var matches = null;
|
|
var name = null;
|
|
|
|
if (elementProperty) {
|
|
matches = elementProperty.match(propertyPattern);
|
|
if (matches) {
|
|
// Convert to lowercase, and remove any whitespace
|
|
// so we can match below.
|
|
name = matches[0].toLowerCase().replace(/\s/g, "");
|
|
// multiple authors
|
|
values[name] = content.trim();
|
|
}
|
|
}
|
|
if (!matches && elementName && namePattern.test(elementName)) {
|
|
name = elementName;
|
|
if (content) {
|
|
// Convert to lowercase, remove any whitespace, and convert dots
|
|
// to colons so we can match below.
|
|
name = name.toLowerCase().replace(/\s/g, "").replace(/\./g, ":");
|
|
values[name] = content.trim();
|
|
}
|
|
}
|
|
});
|
|
|
|
// get title
|
|
metadata.title = jsonld.title ||
|
|
values["dc:title"] ||
|
|
values["dcterm:title"] ||
|
|
values["og:title"] ||
|
|
values["weibo:article:title"] ||
|
|
values["weibo:webpage:title"] ||
|
|
values["title"] ||
|
|
values["twitter:title"];
|
|
|
|
if (!metadata.title) {
|
|
metadata.title = this._getArticleTitle();
|
|
}
|
|
|
|
// get author
|
|
metadata.byline = jsonld.byline ||
|
|
values["dc:creator"] ||
|
|
values["dcterm:creator"] ||
|
|
values["author"];
|
|
|
|
// get description
|
|
metadata.excerpt = jsonld.excerpt ||
|
|
values["dc:description"] ||
|
|
values["dcterm:description"] ||
|
|
values["og:description"] ||
|
|
values["weibo:article:description"] ||
|
|
values["weibo:webpage:description"] ||
|
|
values["description"] ||
|
|
values["twitter:description"];
|
|
|
|
// get site name
|
|
metadata.siteName = jsonld.siteName ||
|
|
values["og:site_name"];
|
|
|
|
// in many sites the meta value is escaped with HTML entities,
|
|
// so here we need to unescape it
|
|
metadata.title = this._unescapeHtmlEntities(metadata.title);
|
|
metadata.byline = this._unescapeHtmlEntities(metadata.byline);
|
|
metadata.excerpt = this._unescapeHtmlEntities(metadata.excerpt);
|
|
metadata.siteName = this._unescapeHtmlEntities(metadata.siteName);
|
|
|
|
return metadata;
|
|
},
|
|
|
|
/**
|
|
* Check if node is image, or if node contains exactly only one image
|
|
* whether as a direct child or as its descendants.
|
|
*
|
|
* @param Element
|
|
**/
|
|
_isSingleImage: function(node) {
|
|
if (node.tagName === "IMG") {
|
|
return true;
|
|
}
|
|
|
|
if (node.children.length !== 1 || node.textContent.trim() !== "") {
|
|
return false;
|
|
}
|
|
|
|
return this._isSingleImage(node.children[0]);
|
|
},
|
|
|
|
/**
|
|
* Find all <noscript> that are located after <img> nodes, and which contain only one
|
|
* <img> element. Replace the first image with the image from inside the <noscript> tag,
|
|
* and remove the <noscript> tag. This improves the quality of the images we use on
|
|
* some sites (e.g. Medium).
|
|
*
|
|
* @param Element
|
|
**/
|
|
_unwrapNoscriptImages: function(doc) {
|
|
// Find img without source or attributes that might contains image, and remove it.
|
|
// This is done to prevent a placeholder img is replaced by img from noscript in next step.
|
|
var imgs = Array.from(doc.getElementsByTagName("img"));
|
|
this._forEachNode(imgs, function(img) {
|
|
for (var i = 0; i < img.attributes.length; i++) {
|
|
var attr = img.attributes[i];
|
|
switch (attr.name) {
|
|
case "src":
|
|
case "srcset":
|
|
case "data-src":
|
|
case "data-srcset":
|
|
return;
|
|
}
|
|
|
|
if (/\.(jpg|jpeg|png|webp)/i.test(attr.value)) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
img.parentNode.removeChild(img);
|
|
});
|
|
|
|
// Next find noscript and try to extract its image
|
|
var noscripts = Array.from(doc.getElementsByTagName("noscript"));
|
|
this._forEachNode(noscripts, function(noscript) {
|
|
// Parse content of noscript and make sure it only contains image
|
|
var tmp = doc.createElement("div");
|
|
tmp.innerHTML = noscript.innerHTML;
|
|
if (!this._isSingleImage(tmp)) {
|
|
return;
|
|
}
|
|
|
|
// If noscript has previous sibling and it only contains image,
|
|
// replace it with noscript content. However we also keep old
|
|
// attributes that might contains image.
|
|
var prevElement = noscript.previousElementSibling;
|
|
if (prevElement && this._isSingleImage(prevElement)) {
|
|
var prevImg = prevElement;
|
|
if (prevImg.tagName !== "IMG") {
|
|
prevImg = prevElement.getElementsByTagName("img")[0];
|
|
}
|
|
|
|
var newImg = tmp.getElementsByTagName("img")[0];
|
|
for (var i = 0; i < prevImg.attributes.length; i++) {
|
|
var attr = prevImg.attributes[i];
|
|
if (attr.value === "") {
|
|
continue;
|
|
}
|
|
|
|
if (attr.name === "src" || attr.name === "srcset" || /\.(jpg|jpeg|png|webp)/i.test(attr.value)) {
|
|
if (newImg.getAttribute(attr.name) === attr.value) {
|
|
continue;
|
|
}
|
|
|
|
var attrName = attr.name;
|
|
if (newImg.hasAttribute(attrName)) {
|
|
attrName = "data-old-" + attrName;
|
|
}
|
|
|
|
newImg.setAttribute(attrName, attr.value);
|
|
}
|
|
}
|
|
|
|
noscript.parentNode.replaceChild(tmp.firstElementChild, prevElement);
|
|
}
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Removes script tags from the document.
|
|
*
|
|
* @param Element
|
|
**/
|
|
_removeScripts: function(doc) {
|
|
this._removeNodes(this._getAllNodesWithTag(doc, ["script"]), function(scriptNode) {
|
|
scriptNode.nodeValue = "";
|
|
scriptNode.removeAttribute("src");
|
|
return true;
|
|
});
|
|
this._removeNodes(this._getAllNodesWithTag(doc, ["noscript"]));
|
|
},
|
|
|
|
/**
|
|
* Check if this node has only whitespace and a single element with given tag
|
|
* Returns false if the DIV node contains non-empty text nodes
|
|
* or if it contains no element with given tag or more than 1 element.
|
|
*
|
|
* @param Element
|
|
* @param string tag of child element
|
|
**/
|
|
_hasSingleTagInsideElement: function(element, tag) {
|
|
// There should be exactly 1 element child with given tag
|
|
if (element.children.length != 1 || element.children[0].tagName !== tag) {
|
|
return false;
|
|
}
|
|
|
|
// And there should be no text nodes with real content
|
|
return !this._someNode(element.childNodes, function(node) {
|
|
return node.nodeType === this.TEXT_NODE &&
|
|
this.REGEXPS.hasContent.test(node.textContent);
|
|
});
|
|
},
|
|
|
|
_isElementWithoutContent: function(node) {
|
|
return node.nodeType === this.ELEMENT_NODE &&
|
|
node.textContent.trim().length == 0 &&
|
|
(node.children.length == 0 ||
|
|
node.children.length == node.getElementsByTagName("br").length + node.getElementsByTagName("hr").length);
|
|
},
|
|
|
|
/**
|
|
* Determine whether element has any children block level elements.
|
|
*
|
|
* @param Element
|
|
*/
|
|
_hasChildBlockElement: function (element) {
|
|
return this._someNode(element.childNodes, function(node) {
|
|
return this.DIV_TO_P_ELEMS.has(node.tagName) ||
|
|
this._hasChildBlockElement(node);
|
|
});
|
|
},
|
|
|
|
/***
|
|
* Determine if a node qualifies as phrasing content.
|
|
* https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Content_categories#Phrasing_content
|
|
**/
|
|
_isPhrasingContent: function(node) {
|
|
return node.nodeType === this.TEXT_NODE || this.PHRASING_ELEMS.indexOf(node.tagName) !== -1 ||
|
|
((node.tagName === "A" || node.tagName === "DEL" || node.tagName === "INS") &&
|
|
this._everyNode(node.childNodes, this._isPhrasingContent));
|
|
},
|
|
|
|
_isWhitespace: function(node) {
|
|
return (node.nodeType === this.TEXT_NODE && node.textContent.trim().length === 0) ||
|
|
(node.nodeType === this.ELEMENT_NODE && node.tagName === "BR");
|
|
},
|
|
|
|
/**
|
|
* Get the inner text of a node - cross browser compatibly.
|
|
* This also strips out any excess whitespace to be found.
|
|
*
|
|
* @param Element
|
|
* @param Boolean normalizeSpaces (default: true)
|
|
* @return string
|
|
**/
|
|
_getInnerText: function(e, normalizeSpaces) {
|
|
normalizeSpaces = (typeof normalizeSpaces === "undefined") ? true : normalizeSpaces;
|
|
var textContent = e.textContent.trim();
|
|
|
|
if (normalizeSpaces) {
|
|
return textContent.replace(this.REGEXPS.normalize, " ");
|
|
}
|
|
return textContent;
|
|
},
|
|
|
|
/**
|
|
* Get the number of times a string s appears in the node e.
|
|
*
|
|
* @param Element
|
|
* @param string - what to split on. Default is ","
|
|
* @return number (integer)
|
|
**/
|
|
_getCharCount: function(e, s) {
|
|
s = s || ",";
|
|
return this._getInnerText(e).split(s).length - 1;
|
|
},
|
|
|
|
/**
|
|
* Remove the style attribute on every e and under.
|
|
* TODO: Test if getElementsByTagName(*) is faster.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
_cleanStyles: function(e) {
|
|
if (!e || e.tagName.toLowerCase() === "svg")
|
|
return;
|
|
|
|
// Remove `style` and deprecated presentational attributes
|
|
for (var i = 0; i < this.PRESENTATIONAL_ATTRIBUTES.length; i++) {
|
|
e.removeAttribute(this.PRESENTATIONAL_ATTRIBUTES[i]);
|
|
}
|
|
|
|
if (this.DEPRECATED_SIZE_ATTRIBUTE_ELEMS.indexOf(e.tagName) !== -1) {
|
|
e.removeAttribute("width");
|
|
e.removeAttribute("height");
|
|
}
|
|
|
|
var cur = e.firstElementChild;
|
|
while (cur !== null) {
|
|
this._cleanStyles(cur);
|
|
cur = cur.nextElementSibling;
|
|
}
|
|
},
|
|
|
|
/**
|
|
* 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 Element
|
|
* @return number (float)
|
|
**/
|
|
_getLinkDensity: function(element) {
|
|
var textLength = this._getInnerText(element).length;
|
|
if (textLength === 0)
|
|
return 0;
|
|
|
|
var linkLength = 0;
|
|
|
|
// XXX implement _reduceNodeList?
|
|
this._forEachNode(element.getElementsByTagName("a"), function(linkNode) {
|
|
var href = linkNode.getAttribute("href");
|
|
var coefficient = href && this.REGEXPS.hashUrl.test(href) ? 0.3 : 1;
|
|
linkLength += this._getInnerText(linkNode).length * coefficient;
|
|
});
|
|
|
|
return linkLength / textLength;
|
|
},
|
|
|
|
/**
|
|
* Get an elements class/id weight. Uses regular expressions to tell if this
|
|
* element looks good or bad.
|
|
*
|
|
* @param Element
|
|
* @return number (Integer)
|
|
**/
|
|
_getClassWeight: function(e) {
|
|
if (!this._flagIsActive(this.FLAG_WEIGHT_CLASSES))
|
|
return 0;
|
|
|
|
var weight = 0;
|
|
|
|
// Look for a special classname
|
|
if (typeof(e.className) === "string" && e.className !== "") {
|
|
if (this.REGEXPS.negative.test(e.className))
|
|
weight -= 25;
|
|
|
|
if (this.REGEXPS.positive.test(e.className))
|
|
weight += 25;
|
|
}
|
|
|
|
// Look for a special ID
|
|
if (typeof(e.id) === "string" && e.id !== "") {
|
|
if (this.REGEXPS.negative.test(e.id))
|
|
weight -= 25;
|
|
|
|
if (this.REGEXPS.positive.test(e.id))
|
|
weight += 25;
|
|
}
|
|
|
|
return weight;
|
|
},
|
|
|
|
/**
|
|
* Clean a node of all elements of type "tag".
|
|
* (Unless it's a youtube/vimeo video. People love movies.)
|
|
*
|
|
* @param Element
|
|
* @param string tag to clean
|
|
* @return void
|
|
**/
|
|
_clean: function(e, tag) {
|
|
var isEmbed = ["object", "embed", "iframe"].indexOf(tag) !== -1;
|
|
|
|
this._removeNodes(this._getAllNodesWithTag(e, [tag]), function(element) {
|
|
// Allow youtube and vimeo videos through as people usually want to see those.
|
|
if (isEmbed) {
|
|
// First, check the elements attributes to see if any of them contain youtube or vimeo
|
|
for (var i = 0; i < element.attributes.length; i++) {
|
|
if (this.REGEXPS.videos.test(element.attributes[i].value)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// For embed with <object> tag, check inner HTML as well.
|
|
if (element.tagName === "object" && this.REGEXPS.videos.test(element.innerHTML)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Check if a given node has one of its ancestor tag name matching the
|
|
* provided one.
|
|
* @param HTMLElement node
|
|
* @param String tagName
|
|
* @param Number maxDepth
|
|
* @param Function filterFn a filter to invoke to determine whether this node 'counts'
|
|
* @return Boolean
|
|
*/
|
|
_hasAncestorTag: function(node, tagName, maxDepth, filterFn) {
|
|
maxDepth = maxDepth || 3;
|
|
tagName = tagName.toUpperCase();
|
|
var depth = 0;
|
|
while (node.parentNode) {
|
|
if (maxDepth > 0 && depth > maxDepth)
|
|
return false;
|
|
if (node.parentNode.tagName === tagName && (!filterFn || filterFn(node.parentNode)))
|
|
return true;
|
|
node = node.parentNode;
|
|
depth++;
|
|
}
|
|
return false;
|
|
},
|
|
|
|
/**
|
|
* Return an object indicating how many rows and columns this table has.
|
|
*/
|
|
_getRowAndColumnCount: function(table) {
|
|
var rows = 0;
|
|
var columns = 0;
|
|
var trs = table.getElementsByTagName("tr");
|
|
for (var i = 0; i < trs.length; i++) {
|
|
var rowspan = trs[i].getAttribute("rowspan") || 0;
|
|
if (rowspan) {
|
|
rowspan = parseInt(rowspan, 10);
|
|
}
|
|
rows += (rowspan || 1);
|
|
|
|
// Now look for column-related info
|
|
var columnsInThisRow = 0;
|
|
var cells = trs[i].getElementsByTagName("td");
|
|
for (var j = 0; j < cells.length; j++) {
|
|
var colspan = cells[j].getAttribute("colspan") || 0;
|
|
if (colspan) {
|
|
colspan = parseInt(colspan, 10);
|
|
}
|
|
columnsInThisRow += (colspan || 1);
|
|
}
|
|
columns = Math.max(columns, columnsInThisRow);
|
|
}
|
|
return {rows: rows, columns: columns};
|
|
},
|
|
|
|
/**
|
|
* Look for 'data' (as opposed to 'layout') tables, for which we use
|
|
* similar checks as
|
|
* https://searchfox.org/mozilla-central/rev/f82d5c549f046cb64ce5602bfd894b7ae807c8f8/accessible/generic/TableAccessible.cpp#19
|
|
*/
|
|
_markDataTables: function(root) {
|
|
var tables = root.getElementsByTagName("table");
|
|
for (var i = 0; i < tables.length; i++) {
|
|
var table = tables[i];
|
|
var role = table.getAttribute("role");
|
|
if (role == "presentation") {
|
|
table._readabilityDataTable = false;
|
|
continue;
|
|
}
|
|
var datatable = table.getAttribute("datatable");
|
|
if (datatable == "0") {
|
|
table._readabilityDataTable = false;
|
|
continue;
|
|
}
|
|
var summary = table.getAttribute("summary");
|
|
if (summary) {
|
|
table._readabilityDataTable = true;
|
|
continue;
|
|
}
|
|
|
|
var caption = table.getElementsByTagName("caption")[0];
|
|
if (caption && caption.childNodes.length > 0) {
|
|
table._readabilityDataTable = true;
|
|
continue;
|
|
}
|
|
|
|
// If the table has a descendant with any of these tags, consider a data table:
|
|
var dataTableDescendants = ["col", "colgroup", "tfoot", "thead", "th"];
|
|
var descendantExists = function(tag) {
|
|
return !!table.getElementsByTagName(tag)[0];
|
|
};
|
|
if (dataTableDescendants.some(descendantExists)) {
|
|
this.log("Data table because found data-y descendant");
|
|
table._readabilityDataTable = true;
|
|
continue;
|
|
}
|
|
|
|
// Nested tables indicate a layout table:
|
|
if (table.getElementsByTagName("table")[0]) {
|
|
table._readabilityDataTable = false;
|
|
continue;
|
|
}
|
|
|
|
var sizeInfo = this._getRowAndColumnCount(table);
|
|
if (sizeInfo.rows >= 10 || sizeInfo.columns > 4) {
|
|
table._readabilityDataTable = true;
|
|
continue;
|
|
}
|
|
// Now just go by size entirely:
|
|
table._readabilityDataTable = sizeInfo.rows * sizeInfo.columns > 10;
|
|
}
|
|
},
|
|
|
|
/* convert images and figures that have properties like data-src into images that can be loaded without JS */
|
|
_fixLazyImages: function (root) {
|
|
this._forEachNode(this._getAllNodesWithTag(root, ["img", "picture", "figure"]), function (elem) {
|
|
// In some sites (e.g. Kotaku), they put 1px square image as base64 data uri in the src attribute.
|
|
// So, here we check if the data uri is too short, just might as well remove it.
|
|
if (elem.src && this.REGEXPS.b64DataUrl.test(elem.src)) {
|
|
// Make sure it's not SVG, because SVG can have a meaningful image in under 133 bytes.
|
|
var parts = this.REGEXPS.b64DataUrl.exec(elem.src);
|
|
if (parts[1] === "image/svg+xml") {
|
|
return;
|
|
}
|
|
|
|
// Make sure this element has other attributes which contains image.
|
|
// If it doesn't, then this src is important and shouldn't be removed.
|
|
var srcCouldBeRemoved = false;
|
|
for (var i = 0; i < elem.attributes.length; i++) {
|
|
var attr = elem.attributes[i];
|
|
if (attr.name === "src") {
|
|
continue;
|
|
}
|
|
|
|
if (/\.(jpg|jpeg|png|webp)/i.test(attr.value)) {
|
|
srcCouldBeRemoved = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Here we assume if image is less than 100 bytes (or 133B after encoded to base64)
|
|
// it will be too small, therefore it might be placeholder image.
|
|
if (srcCouldBeRemoved) {
|
|
var b64starts = elem.src.search(/base64\s*/i) + 7;
|
|
var b64length = elem.src.length - b64starts;
|
|
if (b64length < 133) {
|
|
elem.removeAttribute("src");
|
|
}
|
|
}
|
|
}
|
|
|
|
// also check for "null" to work around https://github.com/jsdom/jsdom/issues/2580
|
|
if ((elem.src || (elem.srcset && elem.srcset != "null")) && elem.className.toLowerCase().indexOf("lazy") === -1) {
|
|
return;
|
|
}
|
|
|
|
for (var j = 0; j < elem.attributes.length; j++) {
|
|
attr = elem.attributes[j];
|
|
if (attr.name === "src" || attr.name === "srcset" || attr.name === "alt") {
|
|
continue;
|
|
}
|
|
var copyTo = null;
|
|
if (/\.(jpg|jpeg|png|webp)\s+\d/.test(attr.value)) {
|
|
copyTo = "srcset";
|
|
} else if (/^\s*\S+\.(jpg|jpeg|png|webp)\S*\s*$/.test(attr.value)) {
|
|
copyTo = "src";
|
|
}
|
|
if (copyTo) {
|
|
//if this is an img or picture, set the attribute directly
|
|
if (elem.tagName === "IMG" || elem.tagName === "PICTURE") {
|
|
elem.setAttribute(copyTo, attr.value);
|
|
} else if (elem.tagName === "FIGURE" && !this._getAllNodesWithTag(elem, ["img", "picture"]).length) {
|
|
//if the item is a <figure> that does not contain an image or picture, create one and place it inside the figure
|
|
//see the nytimes-3 testcase for an example
|
|
var img = this._doc.createElement("img");
|
|
img.setAttribute(copyTo, attr.value);
|
|
elem.appendChild(img);
|
|
}
|
|
}
|
|
}
|
|
});
|
|
},
|
|
|
|
_getTextDensity: function(e, tags) {
|
|
var textLength = this._getInnerText(e, true).length;
|
|
if (textLength === 0) {
|
|
return 0;
|
|
}
|
|
var childrenLength = 0;
|
|
var children = this._getAllNodesWithTag(e, tags);
|
|
this._forEachNode(children, (child) => childrenLength += this._getInnerText(child, true).length);
|
|
return childrenLength / textLength;
|
|
},
|
|
|
|
/**
|
|
* 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.
|
|
*
|
|
* @return void
|
|
**/
|
|
_cleanConditionally: function(e, tag) {
|
|
if (!this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY))
|
|
return;
|
|
|
|
// 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.
|
|
this._removeNodes(this._getAllNodesWithTag(e, [tag]), function(node) {
|
|
// First check if this node IS data table, in which case don't remove it.
|
|
var isDataTable = function(t) {
|
|
return t._readabilityDataTable;
|
|
};
|
|
|
|
var isList = tag === "ul" || tag === "ol";
|
|
if (!isList) {
|
|
var listLength = 0;
|
|
var listNodes = this._getAllNodesWithTag(node, ["ul", "ol"]);
|
|
this._forEachNode(listNodes, (list) => listLength += this._getInnerText(list).length);
|
|
isList = listLength / this._getInnerText(node).length > 0.9;
|
|
}
|
|
|
|
if (tag === "table" && isDataTable(node)) {
|
|
return false;
|
|
}
|
|
|
|
// Next check if we're inside a data table, in which case don't remove it as well.
|
|
if (this._hasAncestorTag(node, "table", -1, isDataTable)) {
|
|
return false;
|
|
}
|
|
|
|
if (this._hasAncestorTag(node, "code")) {
|
|
return false;
|
|
}
|
|
|
|
var weight = this._getClassWeight(node);
|
|
|
|
this.log("Cleaning Conditionally", node);
|
|
|
|
var contentScore = 0;
|
|
|
|
if (weight + contentScore < 0) {
|
|
return true;
|
|
}
|
|
|
|
if (this._getCharCount(node, ",") < 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.
|
|
var p = node.getElementsByTagName("p").length;
|
|
var img = node.getElementsByTagName("img").length;
|
|
var li = node.getElementsByTagName("li").length - 100;
|
|
var input = node.getElementsByTagName("input").length;
|
|
var headingDensity = this._getTextDensity(node, ["h1", "h2", "h3", "h4", "h5", "h6"]);
|
|
|
|
var embedCount = 0;
|
|
var embeds = this._getAllNodesWithTag(node, ["object", "embed", "iframe"]);
|
|
|
|
for (var i = 0; i < embeds.length; i++) {
|
|
// If this embed has attribute that matches video regex, don't delete it.
|
|
for (var j = 0; j < embeds[i].attributes.length; j++) {
|
|
if (this.REGEXPS.videos.test(embeds[i].attributes[j].value)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// For embed with <object> tag, check inner HTML as well.
|
|
if (embeds[i].tagName === "object" && this.REGEXPS.videos.test(embeds[i].innerHTML)) {
|
|
return false;
|
|
}
|
|
|
|
embedCount++;
|
|
}
|
|
|
|
var linkDensity = this._getLinkDensity(node);
|
|
var contentLength = this._getInnerText(node).length;
|
|
|
|
var haveToRemove =
|
|
(img > 1 && p / img < 0.5 && !this._hasAncestorTag(node, "figure")) ||
|
|
(!isList && li > p) ||
|
|
(input > Math.floor(p/3)) ||
|
|
(!isList && headingDensity < 0.9 && contentLength < 25 && (img === 0 || img > 2) && !this._hasAncestorTag(node, "figure")) ||
|
|
(!isList && weight < 25 && linkDensity > 0.2) ||
|
|
(weight >= 25 && linkDensity > 0.5) ||
|
|
((embedCount === 1 && contentLength < 75) || embedCount > 1);
|
|
// Allow simple lists of images to remain in pages
|
|
if (isList && haveToRemove) {
|
|
for (var x = 0; x < node.children.length; x++) {
|
|
let child = node.children[x];
|
|
// Don't filter in lists with li's that contain more than one child
|
|
if (child.children.length > 1) {
|
|
return haveToRemove;
|
|
}
|
|
}
|
|
li_count = node.getElementsByTagName("li").length;
|
|
// Only allow the list to remain if every li contains an image
|
|
if (img == li_count) {
|
|
return false;
|
|
}
|
|
}
|
|
return haveToRemove;
|
|
}
|
|
return false;
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Clean out elements that match the specified conditions
|
|
*
|
|
* @param Element
|
|
* @param Function determines whether a node should be removed
|
|
* @return void
|
|
**/
|
|
_cleanMatchedNodes: function(e, filter) {
|
|
var endOfSearchMarkerNode = this._getNextNode(e, true);
|
|
var next = this._getNextNode(e);
|
|
while (next && next != endOfSearchMarkerNode) {
|
|
if (filter.call(this, next, next.className + " " + next.id)) {
|
|
next = this._removeAndGetNext(next);
|
|
} else {
|
|
next = this._getNextNode(next);
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Clean out spurious headers from an Element.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
_cleanHeaders: function(e) {
|
|
let headingNodes = this._getAllNodesWithTag(e, ["h1", "h2"]);
|
|
this._removeNodes(headingNodes, function(node) {
|
|
let shouldRemove = this._getClassWeight(node) < 0;
|
|
if (shouldRemove) {
|
|
this.log("Removing header with low class weight:", node);
|
|
}
|
|
return shouldRemove;
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Check if this node is an H1 or H2 element whose content is mostly
|
|
* the same as the article title.
|
|
*
|
|
* @param Element the node to check.
|
|
* @return boolean indicating whether this is a title-like header.
|
|
*/
|
|
_headerDuplicatesTitle: function(node) {
|
|
if (node.tagName != "H1" && node.tagName != "H2") {
|
|
return false;
|
|
}
|
|
var heading = this._getInnerText(node, false);
|
|
this.log("Evaluating similarity of header:", heading, this._articleTitle);
|
|
return this._textSimilarity(this._articleTitle, heading) > 0.75;
|
|
},
|
|
|
|
_flagIsActive: function(flag) {
|
|
return (this._flags & flag) > 0;
|
|
},
|
|
|
|
_removeFlag: function(flag) {
|
|
this._flags = this._flags & ~flag;
|
|
},
|
|
|
|
_isProbablyVisible: function(node) {
|
|
// Have to null-check node.style and node.className.indexOf to deal with SVG and MathML nodes.
|
|
return (!node.style || node.style.display != "none")
|
|
&& !node.hasAttribute("hidden")
|
|
//check for "fallback-image" so that wikimedia math images are displayed
|
|
&& (!node.hasAttribute("aria-hidden") || node.getAttribute("aria-hidden") != "true" || (node.className && node.className.indexOf && node.className.indexOf("fallback-image") !== -1));
|
|
},
|
|
|
|
/**
|
|
* Runs readability.
|
|
*
|
|
* Workflow:
|
|
* 1. Prep the document by removing script tags, css, etc.
|
|
* 2. Build readability's DOM tree.
|
|
* 3. Grab the article content from the current dom tree.
|
|
* 4. Replace the current DOM tree with the new one.
|
|
* 5. Read peacefully.
|
|
*
|
|
* @return void
|
|
**/
|
|
parse: function () {
|
|
// Avoid parsing too large documents, as per configuration option
|
|
if (this._maxElemsToParse > 0) {
|
|
var numTags = this._doc.getElementsByTagName("*").length;
|
|
if (numTags > this._maxElemsToParse) {
|
|
throw new Error("Aborting parsing document; " + numTags + " elements found");
|
|
}
|
|
}
|
|
|
|
// Unwrap image from noscript
|
|
this._unwrapNoscriptImages(this._doc);
|
|
|
|
// Extract JSON-LD metadata before removing scripts
|
|
var jsonLd = this._disableJSONLD ? {} : this._getJSONLD(this._doc);
|
|
|
|
// Remove script tags from the document.
|
|
this._removeScripts(this._doc);
|
|
|
|
this._prepDocument();
|
|
|
|
var metadata = this._getArticleMetadata(jsonLd);
|
|
this._articleTitle = metadata.title;
|
|
|
|
var articleContent = this._grabArticle();
|
|
if (!articleContent)
|
|
return null;
|
|
|
|
this.log("Grabbed: " + articleContent.innerHTML);
|
|
|
|
this._postProcessContent(articleContent);
|
|
|
|
// If we haven't found an excerpt in the article's metadata, use the article's
|
|
// first paragraph as the excerpt. This is used for displaying a preview of
|
|
// the article's content.
|
|
if (!metadata.excerpt) {
|
|
var paragraphs = articleContent.getElementsByTagName("p");
|
|
if (paragraphs.length > 0) {
|
|
metadata.excerpt = paragraphs[0].textContent.trim();
|
|
}
|
|
}
|
|
|
|
var textContent = articleContent.textContent;
|
|
return {
|
|
title: this._articleTitle,
|
|
byline: metadata.byline || this._articleByline,
|
|
dir: this._articleDir,
|
|
lang: this._articleLang,
|
|
content: this._serializer(articleContent),
|
|
textContent: textContent,
|
|
length: textContent.length,
|
|
excerpt: metadata.excerpt,
|
|
siteName: metadata.siteName || this._articleSiteName
|
|
};
|
|
}
|
|
};
|
|
|
|
if (typeof module === "object") {
|
|
module.exports = Readability;
|
|
}
|
|
|
|
/* Define a css stylesheet */
|
|
|
|
var style_sheet_simple = `
|
|
<style type="text/css">
|
|
|
|
body {
|
|
padding: 40px 200px 40px 200px;
|
|
background-color: "#FDFDFD";
|
|
font-size: 18px;
|
|
}
|
|
|
|
#readOverlay {
|
|
display: block;
|
|
position: absolute;
|
|
top: 0;
|
|
left: 0;
|
|
width: 100%;
|
|
}
|
|
|
|
</style>`
|
|
/* See also
|
|
* <https://gist.github.com/aanand/399131>
|
|
* and the one included in firefox @ <chrome://global/skin/aboutReader.css>
|
|
*/
|
|
var documentClone = document.cloneNode(true);
|
|
var article = new Readability(documentClone).parse();
|
|
document.head.innerHTML = `<title>${article.title}</title>\n${style_sheet_simple}`
|
|
document.body.innerHTML = `<h1>${article.title}</h1>\n${article.content}`
|