1752 lines
59 KiB
JavaScript
1752 lines
59 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 {Object} uri The URI descriptor object.
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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(uri, doc, options) {
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options = options || {};
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this._uri = uri;
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this._doc = doc;
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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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// 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._wordThreshold = options.wordThreshold || this.DEFAULT_WORD_THRESHOLD;
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this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []);
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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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var logEl;
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// Control whether log messages are sent to the console
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if (this._debug) {
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logEl = function(e) {
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var rv = e.nodeName + " ";
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if (e.nodeType == e.TEXT_NODE) {
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return rv + '("' + e.textContent + '")';
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}
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var classDesc = e.className && ("." + e.className.replace(/ /g, "."));
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var elDesc = "";
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if (e.id)
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elDesc = "(#" + e.id + classDesc + ")";
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else if (classDesc)
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elDesc = "(" + classDesc + ")";
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return rv + elDesc;
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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) ? logEl(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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var args = ["Reader: (Readability) "].concat(arguments);
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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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// 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 words an article must have in order to return a result
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DEFAULT_WORD_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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unlikelyCandidates: /banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|foot|header|legends|menu|modal|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|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: /hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|masthead|media|meta|modal|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)\.com/i,
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nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i,
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prevLink: /(prev|earl|old|new|<|«)/i,
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whitespace: /^\s*$/,
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hasContent: /\S$/,
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},
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DIV_TO_P_ELEMS: [ "A", "BLOCKQUOTE", "DL", "DIV", "IMG", "OL", "P", "PRE", "TABLE", "UL", "SELECT" ],
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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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// These are the IDs and classes that readability sets itself.
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IDS_TO_PRESERVE: [ "readability-content", "readability-page-1" ],
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CLASSES_TO_PRESERVE: [ "readability-styled", "page" ],
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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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// Remove IDs and classes.
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this._cleanIDsAndClasses(articleContent);
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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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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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for (var i = nodeList.length - 1; i >= 0; i--) {
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var node = nodeList[i];
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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, 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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* 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 id="" and class="" attribute from every element in the given
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* subtree, except those that match IDS_TO_PRESERVE, 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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_cleanIDsAndClasses: function(node) {
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if (this.IDS_TO_PRESERVE.indexOf(node.id) == -1) {
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node.removeAttribute("id");
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}
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var classesToPreserve = this._classesToPreserve;
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var className = node.className
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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.className = 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._cleanIDsAndClasses(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 scheme = this._uri.scheme;
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var prePath = this._uri.prePath;
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var pathBase = this._uri.pathBase;
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function toAbsoluteURI(uri) {
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// If this is already an absolute URI, return it.
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if (/^[a-zA-Z][a-zA-Z0-9\+\-\.]*:/.test(uri))
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return uri;
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// Scheme-rooted relative URI.
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if (uri.substr(0, 2) == "//")
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return scheme + "://" + uri.substr(2);
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// Prepath-rooted relative URI.
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if (uri[0] == "/")
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return prePath + uri;
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// Dotslash relative URI.
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if (uri.indexOf("./") === 0)
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return pathBase + uri.slice(2);
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// Ignore hash URIs:
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if (uri[0] == "#")
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return uri;
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// Standard relative URI; add entire path. pathBase already includes a
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// trailing "/".
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return pathBase + uri;
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}
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var links = articleContent.getElementsByTagName("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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// Replace links with javascript: URIs with text content, 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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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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link.setAttribute("href", toAbsoluteURI(href));
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}
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}
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});
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var imgs = articleContent.getElementsByTagName("img");
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this._forEachNode(imgs, function(img) {
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var src = img.getAttribute("src");
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if (src) {
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img.setAttribute("src", toAbsoluteURI(src));
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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 void
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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;
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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');
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// If the resulting title is too short (3 words or fewer), remove
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// the first part instead:
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if (wordCount(curTitle) < 3)
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curTitle = origTitle.replace(/[^\|\-\\\/>»]*[\|\-\\\/>»](.*)/gi, '$1');
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} else if (curTitle.indexOf(': ') !== -1) {
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// Check if we have an heading containing this exact string, so we
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// could assume it's the full title.
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var headings = this._concatNodeLists(
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doc.getElementsByTagName('h1'),
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doc.getElementsByTagName('h2')
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);
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var match = this._someNode(headings, function(heading) {
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return heading.textContent === curTitle;
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});
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// If we don't, let's extract the title out of the original title string.
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if (!match) {
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curTitle = origTitle.substring(origTitle.lastIndexOf(':') + 1);
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// If the title is now too short, try the first colon instead:
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if (wordCount(curTitle) < 3)
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curTitle = origTitle.substring(origTitle.indexOf(':') + 1);
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}
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} else if (curTitle.length > 150 || curTitle.length < 15) {
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var hOnes = doc.getElementsByTagName('h1');
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if (hOnes.length === 1)
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curTitle = this._getInnerText(hOnes[0]);
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}
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curTitle = curTitle.trim();
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// If we now have 4 words or fewer as our title, and either no
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// 'hierarchical' separators (\, /, > or ») were found in the original
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// title or we decreased the number of words by more than 1 word, use
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// the original title.
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var curTitleWordCount = wordCount(curTitle);
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if (curTitleWordCount <= 4 &&
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(!titleHadHierarchicalSeparators ||
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curTitleWordCount != wordCount(origTitle.replace(/[\|\-\\\/>»]+/g, "")) - 1)) {
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curTitle = origTitle;
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}
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return curTitle;
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},
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/**
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* Prepare the HTML document for readability to scrape it.
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* This includes things like stripping javascript, CSS, and handling terrible markup.
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*
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* @return void
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**/
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_prepDocument: function() {
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var doc = this._doc;
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// Remove all style tags in head
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this._removeNodes(doc.getElementsByTagName("style"));
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if (doc.body) {
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this._replaceBrs(doc.body);
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}
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this._replaceNodeTags(doc.getElementsByTagName("font"), "SPAN");
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},
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/**
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* Finds the next element, starting from the given node, and ignoring
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* whitespace in between. If the given node is an element, the same node is
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* returned.
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*/
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_nextElement: function (node) {
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var next = node;
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while (next
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&& (next.nodeType != Node.ELEMENT_NODE)
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&& this.REGEXPS.whitespace.test(next.textContent)) {
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next = next.nextSibling;
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}
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return next;
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},
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/**
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* Replaces 2 or more successive <br> elements with a single <p>.
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* Whitespace between <br> elements are ignored. For example:
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* <div>foo<br>bar<br> <br><br>abc</div>
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* will become:
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* <div>foo<br>bar<p>abc</p></div>
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*/
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_replaceBrs: function (elem) {
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this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {
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var next = br.nextSibling;
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// Whether 2 or more <br> elements have been found and replaced with a
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// <p> block.
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var replaced = false;
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// If we find a <br> chain, remove the <br>s until we hit another element
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// or non-whitespace. This leaves behind the first <br> in the chain
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// (which will be replaced with a <p> later).
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while ((next = this._nextElement(next)) && (next.tagName == "BR")) {
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replaced = true;
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var brSibling = next.nextSibling;
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next.parentNode.removeChild(next);
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next = brSibling;
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}
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// If we removed a <br> chain, replace the remaining <br> with a <p>. Add
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// all sibling nodes as children of the <p> until we hit another <br>
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// chain.
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if (replaced) {
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var p = this._doc.createElement("p");
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br.parentNode.replaceChild(p, br);
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next = p.nextSibling;
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while (next) {
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// If we've hit another <br><br>, we're done adding children to this <p>.
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if (next.tagName == "BR") {
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var nextElem = this._nextElement(next);
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if (nextElem && nextElem.tagName == "BR")
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break;
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}
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// Otherwise, make this node a child of the new <p>.
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var sibling = next.nextSibling;
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p.appendChild(next);
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next = sibling;
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}
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}
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});
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},
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_setNodeTag: function (node, tag) {
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this.log("_setNodeTag", node, tag);
|
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if (node.__JSDOMParser__) {
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node.localName = tag.toLowerCase();
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node.tagName = tag.toUpperCase();
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return node;
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}
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|
|
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++) {
|
|
replacement.setAttribute(node.attributes[i].name, node.attributes[i].value);
|
|
}
|
|
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);
|
|
|
|
// 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, "h1");
|
|
this._clean(articleContent, "footer");
|
|
|
|
// Clean out elements have "share" in their id/class combinations from final top candidates,
|
|
// which means we don't remove the top candidates even they have "share".
|
|
this._forEachNode(articleContent.children, function(topCandidate) {
|
|
this._cleanMatchedNodes(topCandidate, /share/);
|
|
});
|
|
|
|
// If there is only one h2 and its text content substantially equals article title,
|
|
// they are probably using it as a header and not a subheader,
|
|
// so remove it since we already extract the title separately.
|
|
var h2 = articleContent.getElementsByTagName('h2');
|
|
if (h2.length === 1) {
|
|
var lengthSimilarRate = (h2[0].textContent.length - this._articleTitle.length) / this._articleTitle.length;
|
|
if (Math.abs(lengthSimilarRate) < 0.5) {
|
|
var titlesMatch = false;
|
|
if (lengthSimilarRate > 0) {
|
|
titlesMatch = h2[0].textContent.includes(this._articleTitle);
|
|
} else {
|
|
titlesMatch = this._articleTitle.includes(h2[0].textContent);
|
|
}
|
|
if (titlesMatch) {
|
|
this._clean(articleContent, "h2");
|
|
}
|
|
}
|
|
}
|
|
|
|
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");
|
|
|
|
// Remove extra paragraphs
|
|
this._removeNodes(articleContent.getElementsByTagName('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._nextElement(br.nextSibling);
|
|
if (next && next.tagName == "P")
|
|
br.parentNode.removeChild(br);
|
|
});
|
|
},
|
|
|
|
/**
|
|
* 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;
|
|
},
|
|
|
|
/**
|
|
* Like _getNextNode, but for DOM implementations with no
|
|
* firstElementChild/nextElementSibling functionality...
|
|
*/
|
|
_getNextNodeNoElementProperties: function(node, ignoreSelfAndKids) {
|
|
function nextSiblingEl(n) {
|
|
do {
|
|
n = n.nextSibling;
|
|
} while (n && n.nodeType !== n.ELEMENT_NODE);
|
|
return n;
|
|
}
|
|
// First check for kids if those aren't being ignored
|
|
if (!ignoreSelfAndKids && node.children[0]) {
|
|
return node.children[0];
|
|
}
|
|
// Then for siblings...
|
|
var next = nextSiblingEl(node);
|
|
if (next) {
|
|
return next;
|
|
}
|
|
// 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;
|
|
if (node)
|
|
next = nextSiblingEl(node);
|
|
} while (node && !next);
|
|
return node && next;
|
|
},
|
|
|
|
_checkByline: function(node, matchString) {
|
|
if (this._articleByline) {
|
|
return false;
|
|
}
|
|
|
|
if (node.getAttribute !== undefined) {
|
|
var rel = node.getAttribute("rel");
|
|
}
|
|
|
|
if ((rel === "author" || 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 ? true: false);
|
|
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) {
|
|
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;
|
|
|
|
while (node) {
|
|
var matchString = node.className + " " + node.id;
|
|
|
|
// 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;
|
|
}
|
|
|
|
// Remove unlikely candidates
|
|
if (stripUnlikelyCandidates) {
|
|
if (this.REGEXPS.unlikelyCandidates.test(matchString) &&
|
|
!this.REGEXPS.okMaybeItsACandidate.test(matchString) &&
|
|
node.tagName !== "BODY" &&
|
|
node.tagName !== "A") {
|
|
this.log("Removing unlikely candidate - " + 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") {
|
|
// 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._hasSinglePInsideElement(node)) {
|
|
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);
|
|
} else {
|
|
// EXPERIMENTAL
|
|
this._forEachNode(node.childNodes, function(childNode) {
|
|
if (childNode.nodeType === Node.TEXT_NODE && childNode.textContent.trim().length > 0) {
|
|
var p = doc.createElement('p');
|
|
p.textContent = childNode.textContent;
|
|
p.style.display = 'inline';
|
|
p.className = 'readability-styled';
|
|
node.replaceChild(p, childNode);
|
|
}
|
|
});
|
|
}
|
|
}
|
|
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, 3);
|
|
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)
|
|
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:
|
|
var kids = page.childNodes;
|
|
while (kids.length) {
|
|
this.log("Moving child out:", kids[0]);
|
|
topCandidate.appendChild(kids[0]);
|
|
}
|
|
|
|
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);
|
|
// 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";
|
|
var children = articleContent.childNodes;
|
|
while (children.length) {
|
|
div.appendChild(children[0]);
|
|
}
|
|
articleContent.appendChild(div);
|
|
}
|
|
|
|
if (this._debug)
|
|
this.log("Article content after paging: " + articleContent.innerHTML);
|
|
|
|
// Now that we've gone through the full algorithm, check to see if
|
|
// we got any meaningful content. If we didn't, we may need to re-run
|
|
// grabArticle with different flags set. This gives us a higher likelihood of
|
|
// finding the content, and the sieve approach gives us a higher likelihood of
|
|
// finding the -right- content.
|
|
if (this._getInnerText(articleContent, true).length < this._wordThreshold) {
|
|
page.innerHTML = pageCacheHtml;
|
|
|
|
if (this._flagIsActive(this.FLAG_STRIP_UNLIKELYS)) {
|
|
this._removeFlag(this.FLAG_STRIP_UNLIKELYS);
|
|
} else if (this._flagIsActive(this.FLAG_WEIGHT_CLASSES)) {
|
|
this._removeFlag(this.FLAG_WEIGHT_CLASSES);
|
|
} else if (this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY)) {
|
|
this._removeFlag(this.FLAG_CLEAN_CONDITIONALLY);
|
|
} else {
|
|
return null;
|
|
}
|
|
} else {
|
|
// 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;
|
|
},
|
|
|
|
/**
|
|
* Attempts to get excerpt and byline metadata for the article.
|
|
*
|
|
* @return Object with optional "excerpt" and "byline" properties
|
|
*/
|
|
_getArticleMetadata: function() {
|
|
var metadata = {};
|
|
var values = {};
|
|
var metaElements = this._doc.getElementsByTagName("meta");
|
|
|
|
// Match "description", or Twitter's "twitter:description" (Cards)
|
|
// in name attribute.
|
|
var namePattern = /^\s*((twitter)\s*:\s*)?(description|title)\s*$/gi;
|
|
|
|
// Match Facebook's Open Graph title & description properties.
|
|
var propertyPattern = /^\s*og\s*:\s*(description|title)\s*$/gi;
|
|
|
|
// Find description tags.
|
|
this._forEachNode(metaElements, function(element) {
|
|
var elementName = element.getAttribute("name");
|
|
var elementProperty = element.getAttribute("property");
|
|
|
|
if ([elementName, elementProperty].indexOf("author") !== -1) {
|
|
metadata.byline = element.getAttribute("content");
|
|
return;
|
|
}
|
|
|
|
var name = null;
|
|
if (namePattern.test(elementName)) {
|
|
name = elementName;
|
|
} else if (propertyPattern.test(elementProperty)) {
|
|
name = elementProperty;
|
|
}
|
|
|
|
if (name) {
|
|
var content = element.getAttribute("content");
|
|
if (content) {
|
|
// Convert to lowercase and remove any whitespace
|
|
// so we can match below.
|
|
name = name.toLowerCase().replace(/\s/g, '');
|
|
values[name] = content.trim();
|
|
}
|
|
}
|
|
});
|
|
|
|
if ("description" in values) {
|
|
metadata.excerpt = values["description"];
|
|
} else if ("og:description" in values) {
|
|
// Use facebook open graph description.
|
|
metadata.excerpt = values["og:description"];
|
|
} else if ("twitter:description" in values) {
|
|
// Use twitter cards description.
|
|
metadata.excerpt = values["twitter:description"];
|
|
}
|
|
|
|
metadata.title = this._getArticleTitle();
|
|
if (!metadata.title) {
|
|
if ("og:title" in values) {
|
|
// Use facebook open graph title.
|
|
metadata.title = values["og:title"];
|
|
} else if ("twitter:title" in values) {
|
|
// Use twitter cards title.
|
|
metadata.title = values["twitter:title"];
|
|
}
|
|
}
|
|
|
|
return metadata;
|
|
},
|
|
|
|
/**
|
|
* Removes script tags from the document.
|
|
*
|
|
* @param Element
|
|
**/
|
|
_removeScripts: function(doc) {
|
|
this._removeNodes(doc.getElementsByTagName('script'), function(scriptNode) {
|
|
scriptNode.nodeValue = "";
|
|
scriptNode.removeAttribute('src');
|
|
return true;
|
|
});
|
|
this._removeNodes(doc.getElementsByTagName('noscript'));
|
|
},
|
|
|
|
/**
|
|
* Check if this node has only whitespace and a single P element
|
|
* Returns false if the DIV node contains non-empty text nodes
|
|
* or if it contains no P or more than 1 element.
|
|
*
|
|
* @param Element
|
|
**/
|
|
_hasSinglePInsideElement: function(element) {
|
|
// There should be exactly 1 element child which is a P:
|
|
if (element.children.length != 1 || element.children[0].tagName !== "P") {
|
|
return false;
|
|
}
|
|
|
|
// And there should be no text nodes with real content
|
|
return !this._someNode(element.childNodes, function(node) {
|
|
return node.nodeType === Node.TEXT_NODE &&
|
|
this.REGEXPS.hasContent.test(node.textContent);
|
|
});
|
|
},
|
|
|
|
_isElementWithoutContent: function(node) {
|
|
return node.nodeType === Node.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.indexOf(node.tagName) !== -1 ||
|
|
this._hasChildBlockElement(node);
|
|
});
|
|
},
|
|
|
|
/**
|
|
* 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;
|
|
|
|
if (e.className !== 'readability-styled') {
|
|
// 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) {
|
|
linkLength += this._getInnerText(linkNode).length;
|
|
});
|
|
|
|
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(e.getElementsByTagName(tag), function(element) {
|
|
// Allow youtube and vimeo videos through as people usually want to see those.
|
|
if (isEmbed) {
|
|
var attributeValues = [].map.call(element.attributes, function(attr) {
|
|
return attr.value;
|
|
}).join("|");
|
|
|
|
// First, check the elements attributes to see if any of them contain youtube or vimeo
|
|
if (this.REGEXPS.videos.test(attributeValues))
|
|
return false;
|
|
|
|
// Then check the elements inside this element for the same.
|
|
if (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://dxr.mozilla.org/mozilla-central/rev/71224049c0b52ab190564d3ea0eab089a159a4cf/accessible/html/HTMLTableAccessible.cpp#920
|
|
*/
|
|
_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;
|
|
}
|
|
},
|
|
|
|
/**
|
|
* 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;
|
|
|
|
var isList = tag === "ul" || tag === "ol";
|
|
|
|
// 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(e.getElementsByTagName(tag), function(node) {
|
|
// First check if we're in a data table, in which case don't remove us.
|
|
var isDataTable = function(t) {
|
|
return t._readabilityDataTable;
|
|
};
|
|
|
|
if (this._hasAncestorTag(node, "table", -1, isDataTable)) {
|
|
return false;
|
|
}
|
|
|
|
var weight = this._getClassWeight(node);
|
|
var contentScore = 0;
|
|
|
|
this.log("Cleaning Conditionally", node);
|
|
|
|
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 embedCount = 0;
|
|
var embeds = node.getElementsByTagName("embed");
|
|
for (var ei = 0, il = embeds.length; ei < il; ei += 1) {
|
|
if (!this.REGEXPS.videos.test(embeds[ei].src))
|
|
embedCount += 1;
|
|
}
|
|
|
|
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 && 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);
|
|
return haveToRemove;
|
|
}
|
|
return false;
|
|
});
|
|
},
|
|
|
|
/**
|
|
* Clean out elements whose id/class combinations match specific string.
|
|
*
|
|
* @param Element
|
|
* @param RegExp match id/class combination.
|
|
* @return void
|
|
**/
|
|
_cleanMatchedNodes: function(e, regex) {
|
|
var endOfSearchMarkerNode = this._getNextNode(e, true);
|
|
var next = this._getNextNode(e);
|
|
while (next && next != endOfSearchMarkerNode) {
|
|
if (regex.test(next.className + " " + next.id)) {
|
|
next = this._removeAndGetNext(next);
|
|
} else {
|
|
next = this._getNextNode(next);
|
|
}
|
|
}
|
|
},
|
|
|
|
/**
|
|
* Clean out spurious headers from an Element. Checks things like classnames and link density.
|
|
*
|
|
* @param Element
|
|
* @return void
|
|
**/
|
|
_cleanHeaders: function(e) {
|
|
for (var headerIndex = 1; headerIndex < 3; headerIndex += 1) {
|
|
this._removeNodes(e.getElementsByTagName('h' + headerIndex), function (header) {
|
|
return this._getClassWeight(header) < 0;
|
|
});
|
|
}
|
|
},
|
|
|
|
_flagIsActive: function(flag) {
|
|
return (this._flags & flag) > 0;
|
|
},
|
|
|
|
_removeFlag: function(flag) {
|
|
this._flags = this._flags & ~flag;
|
|
},
|
|
|
|
/**
|
|
* Decides whether or not the document is reader-able without parsing the whole thing.
|
|
*
|
|
* @return boolean Whether or not we suspect parse() will suceeed at returning an article object.
|
|
*/
|
|
isProbablyReaderable: function(helperIsVisible) {
|
|
var nodes = this._getAllNodesWithTag(this._doc, ["p", "pre"]);
|
|
|
|
// Get <div> nodes which have <br> node(s) and append them into the `nodes` variable.
|
|
// Some articles' DOM structures might look like
|
|
// <div>
|
|
// Sentences<br>
|
|
// <br>
|
|
// Sentences<br>
|
|
// </div>
|
|
var brNodes = this._getAllNodesWithTag(this._doc, ["div > br"]);
|
|
if (brNodes.length) {
|
|
var set = new Set();
|
|
[].forEach.call(brNodes, function(node) {
|
|
set.add(node.parentNode);
|
|
});
|
|
nodes = [].concat.apply(Array.from(set), nodes);
|
|
}
|
|
|
|
// FIXME we should have a fallback for helperIsVisible, but this is
|
|
// problematic because of jsdom's elem.style handling - see
|
|
// https://github.com/mozilla/readability/pull/186 for context.
|
|
|
|
var score = 0;
|
|
// This is a little cheeky, we use the accumulator 'score' to decide what to return from
|
|
// this callback:
|
|
return this._someNode(nodes, function(node) {
|
|
if (helperIsVisible && !helperIsVisible(node))
|
|
return false;
|
|
var matchString = node.className + " " + node.id;
|
|
|
|
if (this.REGEXPS.unlikelyCandidates.test(matchString) &&
|
|
!this.REGEXPS.okMaybeItsACandidate.test(matchString)) {
|
|
return false;
|
|
}
|
|
|
|
if (node.matches && node.matches("li p")) {
|
|
return false;
|
|
}
|
|
|
|
var textContentLength = node.textContent.trim().length;
|
|
if (textContentLength < 140) {
|
|
return false;
|
|
}
|
|
|
|
score += Math.sqrt(textContentLength - 140);
|
|
|
|
if (score > 20) {
|
|
return true;
|
|
}
|
|
return false;
|
|
});
|
|
},
|
|
|
|
/**
|
|
* 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");
|
|
}
|
|
}
|
|
|
|
if (typeof this._doc.documentElement.firstElementChild === "undefined") {
|
|
this._getNextNode = this._getNextNodeNoElementProperties;
|
|
}
|
|
// Remove script tags from the document.
|
|
this._removeScripts(this._doc);
|
|
|
|
this._prepDocument();
|
|
|
|
var metadata = this._getArticleMetadata();
|
|
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 {
|
|
uri: this._uri,
|
|
title: this._articleTitle,
|
|
byline: metadata.byline || this._articleByline,
|
|
dir: this._articleDir,
|
|
content: articleContent.innerHTML,
|
|
textContent: textContent,
|
|
length: textContent.length,
|
|
excerpt: metadata.excerpt,
|
|
};
|
|
}
|
|
};
|
|
|
|
if (typeof module === "object") {
|
|
module.exports = Readability;
|
|
}
|