/* * Copyright (c) 2010 Arc90 Inc * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * This code is heavily based on Arc90's readability.js (1.7.1) script * available at: http://code.google.com/p/arc90labs-readability */ /** * Public constructor. * @param {HTMLDocument} doc The document to parse. * @param {Object} options The options object. */ function Readability(doc, options) { // In some older versions, people passed a URI as the first argument. Cope: if (options && options.documentElement) { doc = options; options = arguments[2]; } else if (!doc || !doc.documentElement) { throw new Error("First argument to Readability constructor should be a document object."); } options = options || {}; this._doc = doc; this._docJSDOMParser = this._doc.firstChild.__JSDOMParser__; this._articleTitle = null; this._articleByline = null; this._articleDir = null; this._articleSiteName = null; this._attempts = []; // Configurable options this._debug = !!options.debug; this._maxElemsToParse = options.maxElemsToParse || this.DEFAULT_MAX_ELEMS_TO_PARSE; this._nbTopCandidates = options.nbTopCandidates || this.DEFAULT_N_TOP_CANDIDATES; this._charThreshold = options.charThreshold || this.DEFAULT_CHAR_THRESHOLD; this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []); this._keepClasses = !!options.keepClasses; this._serializer = options.serializer || function(el) { return el.innerHTML; }; this._disableJSONLD = !!options.disableJSONLD; this._allowedVideoRegex = options.allowedVideoRegex || this.REGEXPS.videos; // Start with all flags set this._flags = this.FLAG_STRIP_UNLIKELYS | this.FLAG_WEIGHT_CLASSES | this.FLAG_CLEAN_CONDITIONALLY; // Control whether log messages are sent to the console if (this._debug) { let logNode = function(node) { if (node.nodeType == node.TEXT_NODE) { return `${node.nodeName} ("${node.textContent}")`; } let attrPairs = Array.from(node.attributes || [], function(attr) { return `${attr.name}="${attr.value}"`; }).join(" "); return `<${node.localName} ${attrPairs}>`; }; this.log = function () { if (typeof console !== "undefined") { let args = Array.from(arguments, arg => { if (arg && arg.nodeType == this.ELEMENT_NODE) { return logNode(arg); } return arg; }); args.unshift("Reader: (Readability)"); console.log.apply(console, args); } else if (typeof dump !== "undefined") { /* global dump */ var msg = Array.prototype.map.call(arguments, function(x) { return (x && x.nodeName) ? logNode(x) : x; }).join(" "); dump("Reader: (Readability) " + msg + "\n"); } }; } else { this.log = function () {}; } } Readability.prototype = { FLAG_STRIP_UNLIKELYS: 0x1, FLAG_WEIGHT_CLASSES: 0x2, FLAG_CLEAN_CONDITIONALLY: 0x4, // https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType ELEMENT_NODE: 1, TEXT_NODE: 3, // Max number of nodes supported by this parser. Default: 0 (no limit) DEFAULT_MAX_ELEMS_TO_PARSE: 0, // The number of top candidates to consider when analysing how // tight the competition is among candidates. DEFAULT_N_TOP_CANDIDATES: 5, // Element tags to score by default. DEFAULT_TAGS_TO_SCORE: "section,h2,h3,h4,h5,h6,p,td,pre".toUpperCase().split(","), // The default number of chars an article must have in order to return a result DEFAULT_CHAR_THRESHOLD: 500, // All of the regular expressions in use within readability. // Defined up here so we don't instantiate them repeatedly in loops. REGEXPS: { // NOTE: These two regular expressions are duplicated in // Readability-readerable.js. Please keep both copies in sync. unlikelyCandidates: /-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i, okMaybeItsACandidate: /and|article|body|column|content|main|shadow/i, positive: /article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i, negative: /-ad-|hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget/i, extraneous: /print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i, byline: /byline|author|dateline|writtenby|p-author/i, replaceFonts: /<(\/?)font[^>]*>/gi, normalize: /\s{2,}/g, videos: /\/\/(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)/i, shareElements: /(\b|_)(share|sharedaddy)(\b|_)/i, nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i, prevLink: /(prev|earl|old|new|<|«)/i, tokenize: /\W+/g, whitespace: /^\s*$/, hasContent: /\S$/, hashUrl: /^#.+/, srcsetUrl: /(\S+)(\s+[\d.]+[xw])?(\s*(?:,|$))/g, b64DataUrl: /^data:\s*([^\s;,]+)\s*;\s*base64\s*,/i, // Commas as used in Latin, Sindhi, Chinese and various other scripts. // see: https://en.wikipedia.org/wiki/Comma#Comma_variants commas: /\u002C|\u060C|\uFE50|\uFE10|\uFE11|\u2E41|\u2E34|\u2E32|\uFF0C/g, // See: https://schema.org/Article jsonLdArticleTypes: /^Article|AdvertiserContentArticle|NewsArticle|AnalysisNewsArticle|AskPublicNewsArticle|BackgroundNewsArticle|OpinionNewsArticle|ReportageNewsArticle|ReviewNewsArticle|Report|SatiricalArticle|ScholarlyArticle|MedicalScholarlyArticle|SocialMediaPosting|BlogPosting|LiveBlogPosting|DiscussionForumPosting|TechArticle|APIReference$/ }, UNLIKELY_ROLES: [ "menu", "menubar", "complementary", "navigation", "alert", "alertdialog", "dialog" ], DIV_TO_P_ELEMS: new Set([ "BLOCKQUOTE", "DL", "DIV", "IMG", "OL", "P", "PRE", "TABLE", "UL" ]), ALTER_TO_DIV_EXCEPTIONS: ["DIV", "ARTICLE", "SECTION", "P"], PRESENTATIONAL_ATTRIBUTES: [ "align", "background", "bgcolor", "border", "cellpadding", "cellspacing", "frame", "hspace", "rules", "style", "valign", "vspace" ], DEPRECATED_SIZE_ATTRIBUTE_ELEMS: [ "TABLE", "TH", "TD", "HR", "PRE" ], // The commented out elements qualify as phrasing content but tend to be // removed by readability when put into paragraphs, so we ignore them here. PHRASING_ELEMS: [ // "CANVAS", "IFRAME", "SVG", "VIDEO", "ABBR", "AUDIO", "B", "BDO", "BR", "BUTTON", "CITE", "CODE", "DATA", "DATALIST", "DFN", "EM", "EMBED", "I", "IMG", "INPUT", "KBD", "LABEL", "MARK", "MATH", "METER", "NOSCRIPT", "OBJECT", "OUTPUT", "PROGRESS", "Q", "RUBY", "SAMP", "SCRIPT", "SELECT", "SMALL", "SPAN", "STRONG", "SUB", "SUP", "TEXTAREA", "TIME", "VAR", "WBR" ], // These are the classes that readability sets itself. CLASSES_TO_PRESERVE: [ "page" ], // These are the list of HTML entities that need to be escaped. HTML_ESCAPE_MAP: { "lt": "<", "gt": ">", "amp": "&", "quot": '"', "apos": "'", }, /** * Run any post-process modifications to article content as necessary. * * @param Element * @return void **/ _postProcessContent: function(articleContent) { // Readability cannot open relative uris so we convert them to absolute uris. this._fixRelativeUris(articleContent); this._simplifyNestedElements(articleContent); if (!this._keepClasses) { // Remove classes. this._cleanClasses(articleContent); } }, /** * Iterates over a NodeList, calls `filterFn` for each node and removes node * if function returned `true`. * * If function is not passed, removes all the nodes in node list. * * @param NodeList nodeList The nodes to operate on * @param Function filterFn the function to use as a filter * @return void */ _removeNodes: function(nodeList, filterFn) { // Avoid ever operating on live node lists. if (this._docJSDOMParser && nodeList._isLiveNodeList) { throw new Error("Do not pass live node lists to _removeNodes"); } for (var i = nodeList.length - 1; i >= 0; i--) { var node = nodeList[i]; var parentNode = node.parentNode; if (parentNode) { if (!filterFn || filterFn.call(this, node, i, nodeList)) { parentNode.removeChild(node); } } } }, /** * Iterates over a NodeList, and calls _setNodeTag for each node. * * @param NodeList nodeList The nodes to operate on * @param String newTagName the new tag name to use * @return void */ _replaceNodeTags: function(nodeList, newTagName) { // Avoid ever operating on live node lists. if (this._docJSDOMParser && nodeList._isLiveNodeList) { throw new Error("Do not pass live node lists to _replaceNodeTags"); } for (const node of nodeList) { this._setNodeTag(node, newTagName); } }, /** * Iterate over a NodeList, which doesn't natively fully implement the Array * interface. * * For convenience, the current object context is applied to the provided * iterate function. * * @param NodeList nodeList The NodeList. * @param Function fn The iterate function. * @return void */ _forEachNode: function(nodeList, fn) { Array.prototype.forEach.call(nodeList, fn, this); }, /** * Iterate over a NodeList, and return the first node that passes * the supplied test function * * For convenience, the current object context is applied to the provided * test function. * * @param NodeList nodeList The NodeList. * @param Function fn The test function. * @return void */ _findNode: function(nodeList, fn) { return Array.prototype.find.call(nodeList, fn, this); }, /** * Iterate over a NodeList, return true if any of the provided iterate * function calls returns true, false otherwise. * * For convenience, the current object context is applied to the * provided iterate function. * * @param NodeList nodeList The NodeList. * @param Function fn The iterate function. * @return Boolean */ _someNode: function(nodeList, fn) { return Array.prototype.some.call(nodeList, fn, this); }, /** * Iterate over a NodeList, return true if all of the provided iterate * function calls return true, false otherwise. * * For convenience, the current object context is applied to the * provided iterate function. * * @param NodeList nodeList The NodeList. * @param Function fn The iterate function. * @return Boolean */ _everyNode: function(nodeList, fn) { return Array.prototype.every.call(nodeList, fn, this); }, /** * Concat all nodelists passed as arguments. * * @return ...NodeList * @return Array */ _concatNodeLists: function() { var slice = Array.prototype.slice; var args = slice.call(arguments); var nodeLists = args.map(function(list) { return slice.call(list); }); return Array.prototype.concat.apply([], nodeLists); }, _getAllNodesWithTag: function(node, tagNames) { if (node.querySelectorAll) { return node.querySelectorAll(tagNames.join(",")); } return [].concat.apply([], tagNames.map(function(tag) { var collection = node.getElementsByTagName(tag); return Array.isArray(collection) ? collection : Array.from(collection); })); }, /** * Removes the class="" attribute from every element in the given * subtree, except those that match CLASSES_TO_PRESERVE and * the classesToPreserve array from the options object. * * @param Element * @return void */ _cleanClasses: function(node) { var classesToPreserve = this._classesToPreserve; var className = (node.getAttribute("class") || "") .split(/\s+/) .filter(function(cls) { return classesToPreserve.indexOf(cls) != -1; }) .join(" "); if (className) { node.setAttribute("class", className); } else { node.removeAttribute("class"); } for (node = node.firstElementChild; node; node = node.nextElementSibling) { this._cleanClasses(node); } }, /** * Converts each and uri in the given element to an absolute URI, * ignoring #ref URIs. * * @param Element * @return void */ _fixRelativeUris: function(articleContent) { var baseURI = this._doc.baseURI; var documentURI = this._doc.documentURI; function toAbsoluteURI(uri) { // Leave hash links alone if the base URI matches the document URI: if (baseURI == documentURI && uri.charAt(0) == "#") { return uri; } // Otherwise, resolve against base URI: try { return new URL(uri, baseURI).href; } catch (ex) { // Something went wrong, just return the original: } return uri; } var links = this._getAllNodesWithTag(articleContent, ["a"]); this._forEachNode(links, function(link) { var href = link.getAttribute("href"); if (href) { // Remove links with javascript: URIs, since // they won't work after scripts have been removed from the page. if (href.indexOf("javascript:") === 0) { // if the link only contains simple text content, it can be converted to a text node if (link.childNodes.length === 1 && link.childNodes[0].nodeType === this.TEXT_NODE) { var text = this._doc.createTextNode(link.textContent); link.parentNode.replaceChild(text, link); } else { // if the link has multiple children, they should all be preserved var container = this._doc.createElement("span"); while (link.firstChild) { container.appendChild(link.firstChild); } link.parentNode.replaceChild(container, link); } } else { link.setAttribute("href", toAbsoluteURI(href)); } } }); var medias = this._getAllNodesWithTag(articleContent, [ "img", "picture", "figure", "video", "audio", "source" ]); this._forEachNode(medias, function(media) { var src = media.getAttribute("src"); var poster = media.getAttribute("poster"); var srcset = media.getAttribute("srcset"); if (src) { media.setAttribute("src", toAbsoluteURI(src)); } if (poster) { media.setAttribute("poster", toAbsoluteURI(poster)); } if (srcset) { var newSrcset = srcset.replace(this.REGEXPS.srcsetUrl, function(_, p1, p2, p3) { return toAbsoluteURI(p1) + (p2 || "") + p3; }); media.setAttribute("srcset", newSrcset); } }); }, _simplifyNestedElements: function(articleContent) { var node = articleContent; while (node) { if (node.parentNode && ["DIV", "SECTION"].includes(node.tagName) && !(node.id && node.id.startsWith("readability"))) { if (this._isElementWithoutContent(node)) { node = this._removeAndGetNext(node); continue; } else if (this._hasSingleTagInsideElement(node, "DIV") || this._hasSingleTagInsideElement(node, "SECTION")) { var child = node.children[0]; for (var i = 0; i < node.attributes.length; i++) { child.setAttribute(node.attributes[i].name, node.attributes[i].value); } node.parentNode.replaceChild(child, node); node = child; continue; } } node = this._getNextNode(node); } }, /** * Get the article title as an H1. * * @return string **/ _getArticleTitle: function() { var doc = this._doc; var curTitle = ""; var origTitle = ""; try { curTitle = origTitle = doc.title.trim(); // If they had an element with id "title" in their HTML if (typeof curTitle !== "string") curTitle = origTitle = this._getInnerText(doc.getElementsByTagName("title")[0]); } catch (e) {/* ignore exceptions setting the title. */} var titleHadHierarchicalSeparators = false; function wordCount(str) { return str.split(/\s+/).length; } // If there's a separator in the title, first remove the final part if ((/ [\|\-\\\/>»] /).test(curTitle)) { titleHadHierarchicalSeparators = / [\\\/>»] /.test(curTitle); 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
elements with a single

. * Whitespace between
elements are ignored. For example: *

foo
bar


abc
* will become: *
foo
bar

abc

*/ _replaceBrs: function (elem) { this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) { var next = br.nextSibling; // Whether 2 or more
elements have been found and replaced with a //

block. var replaced = false; // If we find a
chain, remove the
s until we hit another node // or non-whitespace. This leaves behind the first
in the chain // (which will be replaced with a

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
chain, replace the remaining
with a

. Add // all sibling nodes as children of the

until we hit another
// chain. if (replaced) { var p = this._doc.createElement("p"); br.parentNode.replaceChild(p, br); next = p.nextSibling; while (next) { // If we've hit another

, we're done adding children to this

. 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

. 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

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; } // User is not able to see elements applied with both "aria-modal = true" and "role = dialog" if (node.getAttribute("aria-modal") == "true" && node.getAttribute("role") == "dialog") { 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(this.REGEXPS.commas).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*\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(); } if (typeof parsed.datePublished === "string") { metadata.datePublished = parsed.datePublished.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*(article|dc|dcterm|og|twitter)\s*:\s*(author|creator|description|published_time|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"]; // get article published time metadata.publishedTime = jsonld.datePublished || values["article:published_time"] || null; // 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); metadata.publishedTime = this._unescapeHtmlEntities(metadata.publishedTime); 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