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Diffstat (limited to 'toolkit/components/reader/Readability.js')
| -rw-r--r-- | toolkit/components/reader/Readability.js | 1863 |
1 files changed, 1863 insertions, 0 deletions
diff --git a/toolkit/components/reader/Readability.js b/toolkit/components/reader/Readability.js new file mode 100644 index 000000000..491461a8e --- /dev/null +++ b/toolkit/components/reader/Readability.js @@ -0,0 +1,1863 @@ +/*eslint-env es6:false*/ +/* + * DO NOT MODIFY THIS FILE DIRECTLY! + * + * This is a shared library that is maintained in an external repo: + * https://github.com/mozilla/readability + */ + +/* + * 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 {Object} uri The URI descriptor object. + * @param {HTMLDocument} doc The document to parse. + * @param {Object} options The options object. + */ +function Readability(uri, doc, options) { + options = options || {}; + + this._uri = uri; + this._doc = doc; + this._biggestFrame = false; + this._articleByline = null; + this._articleDir = null; + + // Configureable 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._maxPages = options.maxPages || this.DEFAULT_MAX_PAGES; + + // Start with all flags set + this._flags = this.FLAG_STRIP_UNLIKELYS | + this.FLAG_WEIGHT_CLASSES | + this.FLAG_CLEAN_CONDITIONALLY; + + // The list of pages we've parsed in this call of readability, + // for autopaging. As a key store for easier searching. + this._parsedPages = {}; + + // A list of the ETag headers of pages we've parsed, in case they happen to match, + // we'll know it's a duplicate. + this._pageETags = {}; + + // Make an AJAX request for each page and append it to the document. + this._curPageNum = 1; + + var logEl; + + // Control whether log messages are sent to the console + if (this._debug) { + logEl = function(e) { + var rv = e.nodeName + " "; + if (e.nodeType == e.TEXT_NODE) { + return rv + '("' + e.textContent + '")'; + } + var classDesc = e.className && ("." + e.className.replace(/ /g, ".")); + var elDesc = ""; + if (e.id) + elDesc = "(#" + e.id + classDesc + ")"; + else if (classDesc) + elDesc = "(" + classDesc + ")"; + return rv + elDesc; + }; + this.log = function () { + if (typeof dump !== undefined) { + var msg = Array.prototype.map.call(arguments, function(x) { + return (x && x.nodeName) ? logEl(x) : x; + }).join(" "); + dump("Reader: (Readability) " + msg + "\n"); + } else if (typeof console !== undefined) { + var args = ["Reader: (Readability) "].concat(arguments); + console.log.apply(console, args); + } + }; + } else { + this.log = function () {}; + } +} + +Readability.prototype = { + FLAG_STRIP_UNLIKELYS: 0x1, + FLAG_WEIGHT_CLASSES: 0x2, + FLAG_CLEAN_CONDITIONALLY: 0x4, + + // 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, + + // The maximum number of pages to loop through before we call + // it quits and just show a link. + DEFAULT_MAX_PAGES: 5, + + // Element tags to score by default. + DEFAULT_TAGS_TO_SCORE: "section,h2,h3,h4,h5,h6,p,td,pre".toUpperCase().split(","), + + // All of the regular expressions in use within readability. + // Defined up here so we don't instantiate them repeatedly in loops. + REGEXPS: { + unlikelyCandidates: /banner|combx|comment|community|disqus|extra|foot|header|menu|modal|related|remark|rss|share|shoutbox|sidebar|skyscraper|sponsor|ad-break|agegate|pagination|pager|popup/i, + okMaybeItsACandidate: /and|article|body|column|main|shadow/i, + positive: /article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i, + 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, + 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)\.com/i, + nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i, + prevLink: /(prev|earl|old|new|<|«)/i, + whitespace: /^\s*$/, + hasContent: /\S$/, + }, + + DIV_TO_P_ELEMS: [ "A", "BLOCKQUOTE", "DL", "DIV", "IMG", "OL", "P", "PRE", "TABLE", "UL", "SELECT" ], + + ALTER_TO_DIV_EXCEPTIONS: ["DIV", "ARTICLE", "SECTION", "P"], + + /** + * 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); + }, + + /** + * 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 no + * @param Function filterFn + * @return void + */ + _removeNodes: function(nodeList, filterFn) { + 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); + } + } + } + }, + + /** + * 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. + * @param Boolean backward Whether to use backward iteration. + * @return void + */ + _forEachNode: function(nodeList, fn, backward) { + Array.prototype.forEach.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); + }, + + /** + * 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); + })); + }, + + /** + * Converts each <a> and <img> uri in the given element to an absolute URI, + * ignoring #ref URIs. + * + * @param Element + * @return void + */ + _fixRelativeUris: function(articleContent) { + var scheme = this._uri.scheme; + var prePath = this._uri.prePath; + var pathBase = this._uri.pathBase; + + function toAbsoluteURI(uri) { + // If this is already an absolute URI, return it. + if (/^[a-zA-Z][a-zA-Z0-9\+\-\.]*:/.test(uri)) + return uri; + + // Scheme-rooted relative URI. + if (uri.substr(0, 2) == "//") + return scheme + "://" + uri.substr(2); + + // Prepath-rooted relative URI. + if (uri[0] == "/") + return prePath + uri; + + // Dotslash relative URI. + if (uri.indexOf("./") === 0) + return pathBase + uri.slice(2); + + // Ignore hash URIs: + if (uri[0] == "#") + return uri; + + // Standard relative URI; add entire path. pathBase already includes a + // trailing "/". + return pathBase + uri; + } + + var links = articleContent.getElementsByTagName("a"); + this._forEachNode(links, function(link) { + var href = link.getAttribute("href"); + if (href) { + // Replace links with javascript: URIs with text content, since + // they won't work after scripts have been removed from the page. + if (href.indexOf("javascript:") === 0) { + var text = this._doc.createTextNode(link.textContent); + link.parentNode.replaceChild(text, link); + } else { + link.setAttribute("href", toAbsoluteURI(href)); + } + } + }); + + var imgs = articleContent.getElementsByTagName("img"); + this._forEachNode(imgs, function(img) { + var src = img.getAttribute("src"); + if (src) { + img.setAttribute("src", toAbsoluteURI(src)); + } + }); + }, + + /** + * Get the article title as an H1. + * + * @return void + **/ + _getArticleTitle: function() { + var doc = this._doc; + var curTitle = ""; + var origTitle = ""; + + try { + curTitle = origTitle = doc.title; + + // 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. */} + + if (curTitle.match(/ [\|\-] /)) { + curTitle = origTitle.replace(/(.*)[\|\-] .*/gi, '$1'); + + if (curTitle.split(' ').length < 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 match = this._someNode(headings, function(heading) { + return heading.textContent === curTitle; + }); + + // 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 (curTitle.split(' ').length < 3) + curTitle = origTitle.substring(origTitle.indexOf(':') + 1); + } + } 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(); + + if (curTitle.split(' ').length <= 4) + 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(doc.getElementsByTagName("style")); + + if (doc.body) { + this._replaceBrs(doc.body); + } + + this._forEachNode(doc.getElementsByTagName("font"), function(fontNode) { + this._setNodeTag(fontNode, "SPAN"); + }); + }, + + /** + * Finds the next element, starting from the given node, and ignoring + * whitespace in between. If the given node is an element, the same node is + * returned. + */ + _nextElement: function (node) { + var next = node; + while (next + && (next.nodeType != Node.ELEMENT_NODE) + && this.REGEXPS.whitespace.test(next.textContent)) { + next = next.nextSibling; + } + return next; + }, + + /** + * Replaces 2 or more successive <br> elements with a single <p>. + * Whitespace between <br> elements are ignored. For example: + * <div>foo<br>bar<br> <br><br>abc</div> + * will become: + * <div>foo<br>bar<p>abc</p></div> + */ + _replaceBrs: function (elem) { + this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) { + var next = br.nextSibling; + + // Whether 2 or more <br> elements have been found and replaced with a + // <p> block. + var replaced = false; + + // If we find a <br> chain, remove the <br>s until we hit another element + // or non-whitespace. This leaves behind the first <br> in the chain + // (which will be replaced with a <p> later). + while ((next = this._nextElement(next)) && (next.tagName == "BR")) { + replaced = true; + var brSibling = next.nextSibling; + next.parentNode.removeChild(next); + next = brSibling; + } + + // If we removed a <br> chain, replace the remaining <br> with a <p>. Add + // all sibling nodes as children of the <p> until we hit another <br> + // chain. + if (replaced) { + var p = this._doc.createElement("p"); + br.parentNode.replaceChild(p, br); + + next = p.nextSibling; + while (next) { + // If we've hit another <br><br>, we're done adding children to this <p>. + if (next.tagName == "BR") { + var nextElem = this._nextElement(next); + if (nextElem && nextElem.tagName == "BR") + break; + } + + // Otherwise, make this node a child of the new <p>. + var sibling = next.nextSibling; + p.appendChild(next); + next = sibling; + } + } + }); + }, + + _setNodeTag: function (node, tag) { + this.log("_setNodeTag", node, tag); + if (node.__JSDOMParser__) { + 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++) { + 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); + + // Clean out junk from the article content + this._cleanConditionally(articleContent, "form"); + this._clean(articleContent, "object"); + this._clean(articleContent, "embed"); + this._clean(articleContent, "h1"); + this._clean(articleContent, "footer"); + + // If there is only one h2, they are probably using it as a header + // and not a subheader, so remove it since we already have a header. + if (articleContent.getElementsByTagName('h2').length === 1) + this._clean(articleContent, "h2"); + + this._clean(articleContent, "iframe"); + 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; + + // Check if any "dir" is set on the toplevel document element + this._articleDir = doc.documentElement.getAttribute("dir"); + + 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; + } + } + + 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; + } 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) { + 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; + + // 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) { + // 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. + var parentOfTopCandidate = topCandidate.parentNode; + var lastScore = topCandidate.readability.contentScore; + // The scores shouldn't get too low. + var scoreThreshold = lastScore / 3; + while (parentOfTopCandidate && parentOfTopCandidate.readability) { + 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; + } + } + + // 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); + var siblings = topCandidate.parentNode.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 (this._curPageNum === 1) { + 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 < 500) { + 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 { + 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"]; + } + + 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); + }); + }, + + /** + * 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) { + e = e || this._doc; + if (!e) + return; + var cur = e.firstChild; + + // Remove any root styles, if we're able. + if (typeof e.removeAttribute === 'function' && e.className !== 'readability-styled') + e.removeAttribute('style'); + + // Go until there are no more child nodes + while (cur !== null) { + if (cur.nodeType === cur.ELEMENT_NODE) { + // Remove style attribute(s) : + if (cur.className !== "readability-styled") + cur.removeAttribute("style"); + + this._cleanStyles(cur); + } + + cur = cur.nextSibling; + } + }, + + /** + * 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; + }, + + /** + * Find a cleaned up version of the current URL, to use for comparing links for possible next-pageyness. + * + * @author Dan Lacy + * @return string the base url + **/ + _findBaseUrl: function() { + var uri = this._uri; + var noUrlParams = uri.path.split("?")[0]; + var urlSlashes = noUrlParams.split("/").reverse(); + var cleanedSegments = []; + var possibleType = ""; + + for (var i = 0, slashLen = urlSlashes.length; i < slashLen; i += 1) { + var segment = urlSlashes[i]; + + // Split off and save anything that looks like a file type. + if (segment.indexOf(".") !== -1) { + possibleType = segment.split(".")[1]; + + // If the type isn't alpha-only, it's probably not actually a file extension. + if (!possibleType.match(/[^a-zA-Z]/)) + segment = segment.split(".")[0]; + } + + // EW-CMS specific segment replacement. Ugly. + // Example: http://www.ew.com/ew/article/0,,20313460_20369436,00.html + if (segment.indexOf(',00') !== -1) + segment = segment.replace(',00', ''); + + // If our first or second segment has anything looking like a page number, remove it. + if (segment.match(/((_|-)?p[a-z]*|(_|-))[0-9]{1,2}$/i) && ((i === 1) || (i === 0))) + segment = segment.replace(/((_|-)?p[a-z]*|(_|-))[0-9]{1,2}$/i, ""); + + var del = false; + + // If this is purely a number, and it's the first or second segment, + // it's probably a page number. Remove it. + if (i < 2 && segment.match(/^\d{1,2}$/)) + del = true; + + // If this is the first segment and it's just "index", remove it. + if (i === 0 && segment.toLowerCase() === "index") + del = true; + + // If our first or second segment is smaller than 3 characters, + // and the first segment was purely alphas, remove it. + if (i < 2 && segment.length < 3 && !urlSlashes[0].match(/[a-z]/i)) + del = true; + + // If it's not marked for deletion, push it to cleanedSegments. + if (!del) + cleanedSegments.push(segment); + } + + // This is our final, cleaned, base article URL. + return uri.scheme + "://" + uri.host + cleanedSegments.reverse().join("/"); + }, + + /** + * Look for any paging links that may occur within the document. + * + * @param body + * @return object (array) + **/ + _findNextPageLink: function(elem) { + var uri = this._uri; + var possiblePages = {}; + var allLinks = elem.getElementsByTagName('a'); + var articleBaseUrl = this._findBaseUrl(); + + // Loop through all links, looking for hints that they may be next-page links. + // Things like having "page" in their textContent, className or id, or being a child + // of a node with a page-y className or id. + // + // Also possible: levenshtein distance? longest common subsequence? + // + // After we do that, assign each page a score, and + for (var i = 0, il = allLinks.length; i < il; i += 1) { + var link = allLinks[i]; + var linkHref = allLinks[i].href.replace(/#.*$/, '').replace(/\/$/, ''); + + // If we've already seen this page, ignore it. + if (linkHref === "" || + linkHref === articleBaseUrl || + linkHref === uri.spec || + linkHref in this._parsedPages) { + continue; + } + + // If it's on a different domain, skip it. + if (uri.host !== linkHref.split(/\/+/g)[1]) + continue; + + var linkText = this._getInnerText(link); + + // If the linkText looks like it's not the next page, skip it. + if (linkText.match(this.REGEXPS.extraneous) || linkText.length > 25) + continue; + + // If the leftovers of the URL after removing the base URL don't contain + // any digits, it's certainly not a next page link. + var linkHrefLeftover = linkHref.replace(articleBaseUrl, ''); + if (!linkHrefLeftover.match(/\d/)) + continue; + + if (!(linkHref in possiblePages)) { + possiblePages[linkHref] = {"score": 0, "linkText": linkText, "href": linkHref}; + } else { + possiblePages[linkHref].linkText += ' | ' + linkText; + } + + var linkObj = possiblePages[linkHref]; + + // If the articleBaseUrl isn't part of this URL, penalize this link. It could + // still be the link, but the odds are lower. + // Example: http://www.actionscript.org/resources/articles/745/1/JavaScript-and-VBScript-Injection-in-ActionScript-3/Page1.html + if (linkHref.indexOf(articleBaseUrl) !== 0) + linkObj.score -= 25; + + var linkData = linkText + ' ' + link.className + ' ' + link.id; + if (linkData.match(this.REGEXPS.nextLink)) + linkObj.score += 50; + + if (linkData.match(/pag(e|ing|inat)/i)) + linkObj.score += 25; + + if (linkData.match(/(first|last)/i)) { + // -65 is enough to negate any bonuses gotten from a > or » in the text, + // If we already matched on "next", last is probably fine. + // If we didn't, then it's bad. Penalize. + if (!linkObj.linkText.match(this.REGEXPS.nextLink)) + linkObj.score -= 65; + } + + if (linkData.match(this.REGEXPS.negative) || linkData.match(this.REGEXPS.extraneous)) + linkObj.score -= 50; + + if (linkData.match(this.REGEXPS.prevLink)) + linkObj.score -= 200; + + // If a parentNode contains page or paging or paginat + var parentNode = link.parentNode; + var positiveNodeMatch = false; + var negativeNodeMatch = false; + + while (parentNode) { + var parentNodeClassAndId = parentNode.className + ' ' + parentNode.id; + + if (!positiveNodeMatch && parentNodeClassAndId && parentNodeClassAndId.match(/pag(e|ing|inat)/i)) { + positiveNodeMatch = true; + linkObj.score += 25; + } + + if (!negativeNodeMatch && parentNodeClassAndId && parentNodeClassAndId.match(this.REGEXPS.negative)) { + // If this is just something like "footer", give it a negative. + // If it's something like "body-and-footer", leave it be. + if (!parentNodeClassAndId.match(this.REGEXPS.positive)) { + linkObj.score -= 25; + negativeNodeMatch = true; + } + } + + parentNode = parentNode.parentNode; + } + + // If the URL looks like it has paging in it, add to the score. + // Things like /page/2/, /pagenum/2, ?p=3, ?page=11, ?pagination=34 + if (linkHref.match(/p(a|g|ag)?(e|ing|ination)?(=|\/)[0-9]{1,2}/i) || linkHref.match(/(page|paging)/i)) + linkObj.score += 25; + + // If the URL contains negative values, give a slight decrease. + if (linkHref.match(this.REGEXPS.extraneous)) + linkObj.score -= 15; + + /** + * Minor punishment to anything that doesn't match our current URL. + * NOTE: I'm finding this to cause more harm than good where something is exactly 50 points. + * Dan, can you show me a counterexample where this is necessary? + * if (linkHref.indexOf(window.location.href) !== 0) { + * linkObj.score -= 1; + * } + **/ + + // If the link text can be parsed as a number, give it a minor bonus, with a slight + // bias towards lower numbered pages. This is so that pages that might not have 'next' + // in their text can still get scored, and sorted properly by score. + var linkTextAsNumber = parseInt(linkText, 10); + if (linkTextAsNumber) { + // Punish 1 since we're either already there, or it's probably + // before what we want anyways. + if (linkTextAsNumber === 1) { + linkObj.score -= 10; + } else { + linkObj.score += Math.max(0, 10 - linkTextAsNumber); + } + } + } + + // Loop thrugh all of our possible pages from above and find our top + // candidate for the next page URL. Require at least a score of 50, which + // is a relatively high confidence that this page is the next link. + var topPage = null; + for (var page in possiblePages) { + if (possiblePages.hasOwnProperty(page)) { + if (possiblePages[page].score >= 50 && + (!topPage || topPage.score < possiblePages[page].score)) + topPage = possiblePages[page]; + } + } + + var nextHref = null; + if (topPage) { + nextHref = topPage.href.replace(/\/$/, ''); + + this.log('NEXT PAGE IS ' + nextHref); + this._parsedPages[nextHref] = true; + } + return nextHref; + }, + + _successfulRequest: function(request) { + return (request.status >= 200 && request.status < 300) || + request.status === 304 || + (request.status === 0 && request.responseText); + }, + + _ajax: function(url, options) { + var request = new XMLHttpRequest(); + + function respondToReadyState(readyState) { + if (request.readyState === 4) { + if (this._successfulRequest(request)) { + if (options.success) + options.success(request); + } else if (options.error) { + options.error(request); + } + } + } + + if (typeof options === 'undefined') + options = {}; + + request.onreadystatechange = respondToReadyState; + + request.open('get', url, true); + request.setRequestHeader('Accept', 'text/html'); + + try { + request.send(options.postBody); + } catch (e) { + if (options.error) + options.error(); + } + + return request; + }, + + _appendNextPage: function(nextPageLink) { + var doc = this._doc; + this._curPageNum += 1; + + var articlePage = doc.createElement("DIV"); + articlePage.id = 'readability-page-' + this._curPageNum; + articlePage.className = 'page'; + articlePage.innerHTML = '<p class="page-separator" title="Page ' + this._curPageNum + '">§</p>'; + + doc.getElementById("readability-content").appendChild(articlePage); + + if (this._curPageNum > this._maxPages) { + var nextPageMarkup = "<div style='text-align: center'><a href='" + nextPageLink + "'>View Next Page</a></div>"; + articlePage.innerHTML = articlePage.innerHTML + nextPageMarkup; + return; + } + + // Now that we've built the article page DOM element, get the page content + // asynchronously and load the cleaned content into the div we created for it. + (function(pageUrl, thisPage) { + this._ajax(pageUrl, { + success: function(r) { + + // First, check to see if we have a matching ETag in headers - if we do, this is a duplicate page. + var eTag = r.getResponseHeader('ETag'); + if (eTag) { + if (eTag in this._pageETags) { + this.log("Exact duplicate page found via ETag. Aborting."); + articlePage.style.display = 'none'; + return; + } + this._pageETags[eTag] = 1; + } + + // TODO: this ends up doubling up page numbers on NYTimes articles. Need to generically parse those away. + var page = doc.createElement("DIV"); + + // Do some preprocessing to our HTML to make it ready for appending. + // - Remove any script tags. Swap and reswap newlines with a unicode + // character because multiline regex doesn't work in javascript. + // - Turn any noscript tags into divs so that we can parse them. This + // allows us to find any next page links hidden via javascript. + // - Turn all double br's into p's - was handled by prepDocument in the original view. + // Maybe in the future abstract out prepDocument to work for both the original document + // and AJAX-added pages. + var responseHtml = r.responseText.replace(/\n/g, '\uffff').replace(/<script.*?>.*?<\/script>/gi, ''); + responseHtml = responseHtml.replace(/\n/g, '\uffff').replace(/<script.*?>.*?<\/script>/gi, ''); + responseHtml = responseHtml.replace(/\uffff/g, '\n').replace(/<(\/?)noscript/gi, '<$1div'); + responseHtml = responseHtml.replace(this.REGEXPS.replaceFonts, '<$1span>'); + + page.innerHTML = responseHtml; + this._replaceBrs(page); + + // Reset all flags for the next page, as they will search through it and + // disable as necessary at the end of grabArticle. + this._flags = 0x1 | 0x2 | 0x4; + + var secondNextPageLink = this._findNextPageLink(page); + + // NOTE: if we end up supporting _appendNextPage(), we'll need to + // change this call to be async + var content = this._grabArticle(page); + + if (!content) { + this.log("No content found in page to append. Aborting."); + return; + } + + // Anti-duplicate mechanism. Essentially, get the first paragraph of our new page. + // Compare it against all of the the previous document's we've gotten. If the previous + // document contains exactly the innerHTML of this first paragraph, it's probably a duplicate. + var firstP = content.getElementsByTagName("P").length ? content.getElementsByTagName("P")[0] : null; + if (firstP && firstP.innerHTML.length > 100) { + for (var i = 1; i <= this._curPageNum; i += 1) { + var rPage = doc.getElementById('readability-page-' + i); + if (rPage && rPage.innerHTML.indexOf(firstP.innerHTML) !== -1) { + this.log('Duplicate of page ' + i + ' - skipping.'); + articlePage.style.display = 'none'; + this._parsedPages[pageUrl] = true; + return; + } + } + } + + this._removeScripts(content); + + thisPage.innerHTML = thisPage.innerHTML + content.innerHTML; + + // After the page has rendered, post process the content. This delay is necessary because, + // in webkit at least, offsetWidth is not set in time to determine image width. We have to + // wait a little bit for reflow to finish before we can fix floating images. + setTimeout((function() { + this._postProcessContent(thisPage); + }).bind(this), 500); + + + if (secondNextPageLink) + this._appendNextPage(secondNextPageLink); + } + }); + }).bind(this)(nextPageLink, articlePage); + }, + + /** + * 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 + * @return Boolean + */ + _hasAncestorTag: function(node, tagName, maxDepth) { + maxDepth = maxDepth || 3; + tagName = tagName.toUpperCase(); + var depth = 0; + while (node.parentNode) { + if (depth > maxDepth) + return false; + if (node.parentNode.tagName === tagName) + return true; + node = node.parentNode; + depth++; + } + return false; + }, + + /** + * 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) { + 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 = + // Make an exception for elements with no p's and exactly 1 img. + (img > p && !this._hasAncestorTag(node, "figure")) || + (!isList && li > p) || + (input > Math.floor(p/3)) || + (!isList && contentLength < 25 && (img === 0 || img > 2)) || + (!isList && weight < 25 && linkDensity > 0.2) || + (weight >= 25 && linkDensity > 0.5) || + ((embedCount === 1 && contentLength < 75) || embedCount > 1); + return haveToRemove; + } + return false; + }); + }, + + /** + * 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; + }, + + _addFlag: function(flag) { + this._flags = this._flags | flag; + }, + + _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); + + // FIXME: Disabled multi-page article support for now as it + // needs more work on infrastructure. + + // Make sure this document is added to the list of parsed pages first, + // so we don't double up on the first page. + // this._parsedPages[uri.spec.replace(/\/$/, '')] = true; + + // Pull out any possible next page link first. + // var nextPageLink = this._findNextPageLink(doc.body); + + this._prepDocument(); + + var metadata = this._getArticleMetadata(); + var articleTitle = metadata.title || this._getArticleTitle(); + + var articleContent = this._grabArticle(); + if (!articleContent) + return null; + + this.log("Grabbed: " + articleContent.innerHTML); + + this._postProcessContent(articleContent); + + // if (nextPageLink) { + // // Append any additional pages after a small timeout so that people + // // can start reading without having to wait for this to finish processing. + // setTimeout((function() { + // this._appendNextPage(nextPageLink); + // }).bind(this), 500); + // } + + // 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: articleTitle, + byline: metadata.byline || this._articleByline, + dir: this._articleDir, + content: articleContent.innerHTML, + textContent: textContent, + length: textContent.length, + excerpt: metadata.excerpt, + }; + } +}; |