Google Git
Sign in
chromium / external / github.com / mozilla / readability / 5a69d4a8eb5247b3b0638b100b34a45650359cb0 / . / Readability.js
blob: b93fec1d7fb7384d181dfeca7ab583687f85eab1 [file] [log] [blame]
/*eslint-env es6:false*/
/*
* 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._articleTitle = null;
this._articleByline = null;
this._articleDir = 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 || []);
// Start with all flags set
this._flags = this.FLAG_STRIP_UNLIKELYS |
this.FLAG_WEIGHT_CLASSES |
this.FLAG_CLEAN_CONDITIONALLY;
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,
// 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: {
unlikelyCandidates: /-ad-|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|foot|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|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|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,
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"],
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" ],
/**
* 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);
// 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) {
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) {
for (var i = nodeList.length - 1; i >= 0; i--) {
var node = nodeList[i];
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, 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 <a> and <img> 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 = 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.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();
// 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(doc.getElementsByTagName("style"));
if (doc.body) {
this._replaceBrs(doc.body);
}
this._replaceNodeTags(doc.getElementsByTagName("font"), "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 != this.ELEMENT_NODE)
&& this.REGEXPS.whitespace.test(next.textContent)) {
next = next.nextSibling;
}
return next;
},
/**
* Replaces 2 or more successive <br> elements with a single <p>.
* Whitespace between <br> elements are ignored. For example:
* <div>foo<br>bar<br> <br><br>abc</div>
* will become:
* <div>foo<br>bar<p>abc</p></div>
*/
_replaceBrs: function (elem) {
this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {
var next = br.nextSibling;
// Whether 2 or more <br> elements have been found and replaced with a
// <p> block.
var replaced = false;
// If we find a <br> chain, remove the <br>s until we hit another 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.nextSibling);
if (nextElem && nextElem.tagName == "BR")
break;
}
if (!this._isPhrasingContent(next))
break;
// Otherwise, make this node a child of the new <p>.
var sibling = next.nextSibling;
p.appendChild(next);
next = sibling;
}
while (p.lastChild && this._isWhitespace(p.lastChild)) {
p.removeChild(p.lastChild);
}
if (p.parentNode.tagName === "P")
this._setNodeTag(p.parentNode, "DIV");
}
});
},
_setNodeTag: function (node, tag) {
this.log("_setNodeTag", node, tag);
if (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);
// Check for data tables before we continue, to avoid removing items in
// those tables, which will often be isolated even though they're
// visually linked to other content-ful elements (text, images, etc.).
this._markDataTables(articleContent);
// Clean out junk from the article content
this._cleanConditionally(articleContent, "form");
this._cleanConditionally(articleContent, "fieldset");
this._clean(articleContent, "object");
this._clean(articleContent, "embed");
this._clean(articleContent, "h1");
this._clean(articleContent, "footer");
this._clean(articleContent, "link");
this._clean(articleContent, "aside");
// Clean out elements have "share" in their id/class combinations from final top candidates,
// which means we don't remove the top candidates even they have "share".
this._forEachNode(articleContent.children, function(topCandidate) {
this._cleanMatchedNodes(topCandidate, /share/);
});
// If there is only one h2 and its text content substantially equals article title,
// they are probably using it as a header and not a subheader,
// so remove it since we already extract the title separately.
var h2 = articleContent.getElementsByTagName("h2");
if (h2.length === 1) {
var lengthSimilarRate = (h2[0].textContent.length - this._articleTitle.length) / this._articleTitle.length;
if (Math.abs(lengthSimilarRate) < 0.5) {
var titlesMatch = false;
if (lengthSimilarRate > 0) {
titlesMatch = h2[0].textContent.includes(this._articleTitle);
} else {
titlesMatch = this._articleTitle.includes(h2[0].textContent);
}
if (titlesMatch) {
this._clean(articleContent, "h2");
}
}
}
this._clean(articleContent, "iframe");
this._clean(articleContent, "input");
this._clean(articleContent, "textarea");
this._clean(articleContent, "select");
this._clean(articleContent, "button");
this._cleanHeaders(articleContent);
// Do these last as the previous stuff may have removed junk
// that will affect these
this._cleanConditionally(articleContent, "table");
this._cleanConditionally(articleContent, "ul");
this._cleanConditionally(articleContent, "div");
// Remove extra paragraphs
this._removeNodes(articleContent.getElementsByTagName("p"), function (paragraph) {
var imgCount = paragraph.getElementsByTagName("img").length;
var embedCount = paragraph.getElementsByTagName("embed").length;
var objectCount = paragraph.getElementsByTagName("object").length;
// At this point, nasty iframes have been removed, only remain embedded video ones.
var iframeCount = paragraph.getElementsByTagName("iframe").length;
var totalCount = imgCount + embedCount + objectCount + iframeCount;
return totalCount === 0 && !this._getInnerText(paragraph, false);
});
this._forEachNode(this._getAllNodesWithTag(articleContent, ["br"]), function(br) {
var next = this._nextElement(br.nextSibling);
if (next && next.tagName == "P")
br.parentNode.removeChild(br);
});
// 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;
},
_checkByline: function(node, matchString) {
if (this._articleByline) {
return false;
}
if (node.getAttribute !== undefined) {
var rel = node.getAttribute("rel");
}
if ((rel === "author" || this.REGEXPS.byline.test(matchString)) && this._isValidByline(node.textContent)) {
this._articleByline = node.textContent.trim();
return true;
}
return false;
},
_getNodeAncestors: function(node, maxDepth) {
maxDepth = maxDepth || 0;
var i = 0, ancestors = [];
while (node.parentNode) {
ancestors.push(node.parentNode);
if (maxDepth && ++i === maxDepth)
break;
node = node.parentNode;
}
return ancestors;
},
/***
* grabArticle - Using a variety of metrics (content score, classname, element types), find the content that is
* most likely to be the stuff a user wants to read. Then return it wrapped up in a div.
*
* @param page a document to run upon. Needs to be a full document, complete with body.
* @return Element
**/
_grabArticle: function (page) {
this.log("**** grabArticle ****");
var doc = this._doc;
var isPaging = (page !== null ? true: false);
page = page ? page : this._doc.body;
// We can't grab an article if we don't have a page!
if (!page) {
this.log("No body found in document. Abort.");
return null;
}
var pageCacheHtml = page.innerHTML;
while (true) {
var stripUnlikelyCandidates = this._flagIsActive(this.FLAG_STRIP_UNLIKELYS);
// First, node prepping. Trash nodes that look cruddy (like ones with the
// class name "comment", etc), and turn divs into P tags where they have been
// used inappropriately (as in, where they contain no other block level elements.)
var elementsToScore = [];
var node = this._doc.documentElement;
while (node) {
var matchString = node.className + " " + node.id;
if (!this._isProbablyVisible(node)) {
this.log("Removing hidden node - " + matchString);
node = this._removeAndGetNext(node);
continue;
}
// Check to see if this node is a byline, and remove it if it is.
if (this._checkByline(node, matchString)) {
node = this._removeAndGetNext(node);
continue;
}
// Remove unlikely candidates
if (stripUnlikelyCandidates) {
if (this.REGEXPS.unlikelyCandidates.test(matchString) &&
!this.REGEXPS.okMaybeItsACandidate.test(matchString) &&
node.tagName !== "BODY" &&
node.tagName !== "A") {
this.log("Removing unlikely candidate - " + matchString);
node = this._removeAndGetNext(node);
continue;
}
}
// Remove DIV, SECTION, and HEADER nodes without any content(e.g. text, image, video, or iframe).
if ((node.tagName === "DIV" || node.tagName === "SECTION" || node.tagName === "HEADER" ||
node.tagName === "H1" || node.tagName === "H2" || node.tagName === "H3" ||
node.tagName === "H4" || node.tagName === "H5" || node.tagName === "H6") &&
this._isElementWithoutContent(node)) {
node = this._removeAndGetNext(node);
continue;
}
if (this.DEFAULT_TAGS_TO_SCORE.indexOf(node.tagName) !== -1) {
elementsToScore.push(node);
}
// Turn all divs that don't have children block level elements into p's
if (node.tagName === "DIV") {
// 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, 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 || !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:
var kids = page.childNodes;
while (kids.length) {
this.log("Moving child out:", kids[0]);
topCandidate.appendChild(kids[0]);
}
page.appendChild(topCandidate);
this._initializeNode(topCandidate);
} else if (topCandidate) {
// Find a better top candidate node if it contains (at least three) nodes which belong to `topCandidates` array
// and whose scores are quite closed with current `topCandidate` node.
var alternativeCandidateAncestors = [];
for (var i = 1; i < topCandidates.length; i++) {
if (topCandidates[i].readability.contentScore / topCandidate.readability.contentScore >= 0.75) {
alternativeCandidateAncestors.push(this._getNodeAncestors(topCandidates[i]));
}
}
var MINIMUM_TOPCANDIDATES = 3;
if (alternativeCandidateAncestors.length >= MINIMUM_TOPCANDIDATES) {
parentOfTopCandidate = topCandidate.parentNode;
while (parentOfTopCandidate.tagName !== "BODY") {
var listsContainingThisAncestor = 0;
for (var ancestorIndex = 0; ancestorIndex < alternativeCandidateAncestors.length && listsContainingThisAncestor < MINIMUM_TOPCANDIDATES; ancestorIndex++) {
listsContainingThisAncestor += Number(alternativeCandidateAncestors[ancestorIndex].includes(parentOfTopCandidate));
}
if (listsContainingThisAncestor >= MINIMUM_TOPCANDIDATES) {
topCandidate = parentOfTopCandidate;
break;
}
parentOfTopCandidate = parentOfTopCandidate.parentNode;
}
}
if (!topCandidate.readability) {
this._initializeNode(topCandidate);
}
// Because of our bonus system, parents of candidates might have scores
// themselves. They get half of the node. There won't be nodes with higher
// scores than our topCandidate, but if we see the score going *up* in the first
// few steps up the tree, that's a decent sign that there might be more content
// lurking in other places that we want to unify in. The sibling stuff
// below does some of that - but only if we've looked high enough up the DOM
// tree.
parentOfTopCandidate = topCandidate.parentNode;
var lastScore = topCandidate.readability.contentScore;
// The scores shouldn't get too low.
var scoreThreshold = lastScore / 3;
while (parentOfTopCandidate.tagName !== "BODY") {
if (!parentOfTopCandidate.readability) {
parentOfTopCandidate = parentOfTopCandidate.parentNode;
continue;
}
var parentScore = parentOfTopCandidate.readability.contentScore;
if (parentScore < scoreThreshold)
break;
if (parentScore > lastScore) {
// Alright! We found a better parent to use.
topCandidate = parentOfTopCandidate;
break;
}
lastScore = parentOfTopCandidate.readability.contentScore;
parentOfTopCandidate = parentOfTopCandidate.parentNode;
}
// If the top candidate is the only child, use parent instead. This will help sibling
// joining logic when adjacent content is actually located in parent's sibling node.
parentOfTopCandidate = topCandidate.parentNode;
while (parentOfTopCandidate.tagName != "BODY" && parentOfTopCandidate.children.length == 1) {
topCandidate = parentOfTopCandidate;
parentOfTopCandidate = topCandidate.parentNode;
}
if (!topCandidate.readability) {
this._initializeNode(topCandidate);
}
}
// Now that we have the top candidate, look through its siblings for content
// that might also be related. Things like preambles, content split by ads
// that we removed, etc.
var articleContent = doc.createElement("DIV");
if (isPaging)
articleContent.id = "readability-content";
var siblingScoreThreshold = Math.max(10, topCandidate.readability.contentScore * 0.2);
// Keep potential top candidate's parent node to try to get text direction of it later.
parentOfTopCandidate = topCandidate.parentNode;
var siblings = parentOfTopCandidate.children;
for (var s = 0, sl = siblings.length; s < sl; s++) {
var sibling = siblings[s];
var append = false;
this.log("Looking at sibling node:", sibling, sibling.readability ? ("with score " + sibling.readability.contentScore) : "");
this.log("Sibling has score", sibling.readability ? sibling.readability.contentScore : "Unknown");
if (sibling === topCandidate) {
append = true;
} else {
var contentBonus = 0;
// Give a bonus if sibling nodes and top candidates have the example same classname
if (sibling.className === topCandidate.className && topCandidate.className !== "")
contentBonus += topCandidate.readability.contentScore * 0.2;
if (sibling.readability &&
((sibling.readability.contentScore + contentBonus) >= siblingScoreThreshold)) {
append = true;
} else if (sibling.nodeName === "P") {
var linkDensity = this._getLinkDensity(sibling);
var nodeContent = this._getInnerText(sibling);
var nodeLength = nodeContent.length;
if (nodeLength > 80 && linkDensity < 0.25) {
append = true;
} else if (nodeLength < 80 && nodeLength > 0 && linkDensity === 0 &&
nodeContent.search(/\.( |$)/) !== -1) {
append = true;
}
}
}
if (append) {
this.log("Appending node:", sibling);
if (this.ALTER_TO_DIV_EXCEPTIONS.indexOf(sibling.nodeName) === -1) {
// We have a node that isn't a common block level element, like a form or td tag.
// Turn it into a div so it doesn't get filtered out later by accident.
this.log("Altering sibling:", sibling, "to div.");
sibling = this._setNodeTag(sibling, "DIV");
}
articleContent.appendChild(sibling);
// siblings is a reference to the children array, and
// sibling is removed from the array when we call appendChild().
// As a result, we must revisit this index since the nodes
// have been shifted.
s -= 1;
sl -= 1;
}
}
if (this._debug)
this.log("Article content pre-prep: " + articleContent.innerHTML);
// So we have all of the content that we need. Now we clean it up for presentation.
this._prepArticle(articleContent);
if (this._debug)
this.log("Article content post-prep: " + articleContent.innerHTML);
if (neededToCreateTopCandidate) {
// We already created a fake div thing, and there wouldn't have been any siblings left
// for the previous loop, so there's no point trying to create a new div, and then
// move all the children over. Just assign IDs and class names here. No need to append
// because that already happened anyway.
topCandidate.id = "readability-page-1";
topCandidate.className = "page";
} else {
var div = doc.createElement("DIV");
div.id = "readability-page-1";
div.className = "page";
var children = articleContent.childNodes;
while (children.length) {
div.appendChild(children[0]);
}
articleContent.appendChild(div);
}
if (this._debug)
this.log("Article content after paging: " + articleContent.innerHTML);
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 a.textLength < b.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;
},
/**
* 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");
// property is a space-separated list of values
var propertyPattern = /\s*(dc|dcterm|og|twitter)\s*:\s*(author|creator|description|title)\s*/gi;
// name is a single value
var namePattern = /^\s*(?:(dc|dcterm|og|twitter)\s*[\.:]\s*)?(author|creator|description|title)\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");
var matches = null;
var name = null;
if (elementProperty) {
matches = elementProperty.match(propertyPattern);
if (matches) {
for (var i = matches.length - 1; i >= 0; i--) {
// Convert to lowercase, and remove any whitespace
// so we can match below.
name = matches[i].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 = values["dc:title"] ||
values["dcterm:title"] ||
values["og:title"] ||
values["title"] ||
values["twitter:title"];
if (!metadata.title) {
metadata.title = this._getArticleTitle();
}
// get author
metadata.byline = values["dc:creator"] ||
values["dcterm:creator"] ||
values["author"];
// get description
metadata.excerpt = values["dc:description"] ||
values["dcterm:description"] ||
values["og:description"] ||
values["description"] ||
values["twitter:description"];
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 element with given tag
* Returns false if the DIV node contains non-empty text nodes
* or if it contains no element with given tag or more than 1 element.
*
* @param Element
* @param string tag of child element
**/
_hasSingleTagInsideElement: function(element, tag) {
// There should be exactly 1 element child with given tag
if (element.children.length != 1 || element.children[0].tagName !== tag) {
return false;
}
// And there should be no text nodes with real content
return !this._someNode(element.childNodes, function(node) {
return node.nodeType === this.TEXT_NODE &&
this.REGEXPS.hasContent.test(node.textContent);
});
},
_isElementWithoutContent: function(node) {
return node.nodeType === this.ELEMENT_NODE &&
node.textContent.trim().length == 0 &&
(node.children.length == 0 ||
node.children.length == node.getElementsByTagName("br").length + node.getElementsByTagName("hr").length);
},
/**
* Determine whether element has any children block level elements.
*
* @param Element
*/
_hasChildBlockElement: function (element) {
return this._someNode(element.childNodes, function(node) {
return this.DIV_TO_P_ELEMS.indexOf(node.tagName) !== -1 ||
this._hasChildBlockElement(node);
});
},
/***
* Determine if a node qualifies as phrasing content.
* https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Content_categories#Phrasing_content
**/
_isPhrasingContent: function(node) {
return node.nodeType === this.TEXT_NODE || this.PHRASING_ELEMS.indexOf(node.tagName) !== -1 ||
((node.tagName === "A" || node.tagName === "DEL" || node.tagName === "INS") &&
this._everyNode(node.childNodes, this._isPhrasingContent));
},
_isWhitespace: function(node) {
return (node.nodeType === this.TEXT_NODE && node.textContent.trim().length === 0) ||
(node.nodeType === this.ELEMENT_NODE && node.tagName === "BR");
},
/**
* Get the inner text of a node - cross browser compatibly.
* This also strips out any excess whitespace to be found.
*
* @param Element
* @param Boolean normalizeSpaces (default: true)
* @return string
**/
_getInnerText: function(e, normalizeSpaces) {
normalizeSpaces = (typeof normalizeSpaces === "undefined") ? true : normalizeSpaces;
var textContent = e.textContent.trim();
if (normalizeSpaces) {
return textContent.replace(this.REGEXPS.normalize, " ");
}
return textContent;
},
/**
* Get the number of times a string s appears in the node e.
*
* @param Element
* @param string - what to split on. Default is ","
* @return number (integer)
**/
_getCharCount: function(e, s) {
s = s || ",";
return this._getInnerText(e).split(s).length - 1;
},
/**
* Remove the style attribute on every e and under.
* TODO: Test if getElementsByTagName(*) is faster.
*
* @param Element
* @return void
**/
_cleanStyles: function(e) {
if (!e || e.tagName.toLowerCase() === "svg")
return;
// Remove `style` and deprecated presentational attributes
for (var i = 0; i < this.PRESENTATIONAL_ATTRIBUTES.length; i++) {
e.removeAttribute(this.PRESENTATIONAL_ATTRIBUTES[i]);
}
if (this.DEPRECATED_SIZE_ATTRIBUTE_ELEMS.indexOf(e.tagName) !== -1) {
e.removeAttribute("width");
e.removeAttribute("height");
}
var cur = e.firstElementChild;
while (cur !== null) {
this._cleanStyles(cur);
cur = cur.nextElementSibling;
}
},
/**
* Get the density of links as a percentage of the content
* This is the amount of text that is inside a link divided by the total text in the node.
*
* @param Element
* @return number (float)
**/
_getLinkDensity: function(element) {
var textLength = this._getInnerText(element).length;
if (textLength === 0)
return 0;
var linkLength = 0;
// XXX implement _reduceNodeList?
this._forEachNode(element.getElementsByTagName("a"), function(linkNode) {
linkLength += this._getInnerText(linkNode).length;
});
return linkLength / textLength;
},
/**
* Get an elements class/id weight. Uses regular expressions to tell if this
* element looks good or bad.
*
* @param Element
* @return number (Integer)
**/
_getClassWeight: function(e) {
if (!this._flagIsActive(this.FLAG_WEIGHT_CLASSES))
return 0;
var weight = 0;
// Look for a special classname
if (typeof(e.className) === "string" && e.className !== "") {
if (this.REGEXPS.negative.test(e.className))
weight -= 25;
if (this.REGEXPS.positive.test(e.className))
weight += 25;
}
// Look for a special ID
if (typeof(e.id) === "string" && e.id !== "") {
if (this.REGEXPS.negative.test(e.id))
weight -= 25;
if (this.REGEXPS.positive.test(e.id))
weight += 25;
}
return weight;
},
/**
* Clean a node of all elements of type "tag".
* (Unless it's a youtube/vimeo video. People love movies.)
*
* @param Element
* @param string tag to clean
* @return void
**/
_clean: function(e, tag) {
var isEmbed = ["object", "embed", "iframe"].indexOf(tag) !== -1;
this._removeNodes(e.getElementsByTagName(tag), function(element) {
// Allow youtube and vimeo videos through as people usually want to see those.
if (isEmbed) {
var attributeValues = [].map.call(element.attributes, function(attr) {
return attr.value;
}).join("|");
// First, check the elements attributes to see if any of them contain youtube or vimeo
if (this.REGEXPS.videos.test(attributeValues))
return false;
// Then check the elements inside this element for the same.
if (this.REGEXPS.videos.test(element.innerHTML))
return false;
}
return true;
});
},
/**
* Check if a given node has one of its ancestor tag name matching the
* provided one.
* @param HTMLElement node
* @param String tagName
* @param Number maxDepth
* @param Function filterFn a filter to invoke to determine whether this node 'counts'
* @return Boolean
*/
_hasAncestorTag: function(node, tagName, maxDepth, filterFn) {
maxDepth = maxDepth || 3;
tagName = tagName.toUpperCase();
var depth = 0;
while (node.parentNode) {
if (maxDepth > 0 && depth > maxDepth)
return false;
if (node.parentNode.tagName === tagName && (!filterFn || filterFn(node.parentNode)))
return true;
node = node.parentNode;
depth++;
}
return false;
},
/**
* Return an object indicating how many rows and columns this table has.
*/
_getRowAndColumnCount: function(table) {
var rows = 0;
var columns = 0;
var trs = table.getElementsByTagName("tr");
for (var i = 0; i < trs.length; i++) {
var rowspan = trs[i].getAttribute("rowspan") || 0;
if (rowspan) {
rowspan = parseInt(rowspan, 10);
}
rows += (rowspan || 1);
// Now look for column-related info
var columnsInThisRow = 0;
var cells = trs[i].getElementsByTagName("td");
for (var j = 0; j < cells.length; j++) {
var colspan = cells[j].getAttribute("colspan") || 0;
if (colspan) {
colspan = parseInt(colspan, 10);
}
columnsInThisRow += (colspan || 1);
}
columns = Math.max(columns, columnsInThisRow);
}
return {rows: rows, columns: columns};
},
/**
* Look for 'data' (as opposed to 'layout') tables, for which we use
* similar checks as
* https://dxr.mozilla.org/mozilla-central/rev/71224049c0b52ab190564d3ea0eab089a159a4cf/accessible/html/HTMLTableAccessible.cpp#920
*/
_markDataTables: function(root) {
var tables = root.getElementsByTagName("table");
for (var i = 0; i < tables.length; i++) {
var table = tables[i];
var role = table.getAttribute("role");
if (role == "presentation") {
table._readabilityDataTable = false;
continue;
}
var datatable = table.getAttribute("datatable");
if (datatable == "0") {
table._readabilityDataTable = false;
continue;
}
var summary = table.getAttribute("summary");
if (summary) {
table._readabilityDataTable = true;
continue;
}
var caption = table.getElementsByTagName("caption")[0];
if (caption && caption.childNodes.length > 0) {
table._readabilityDataTable = true;
continue;
}
// If the table has a descendant with any of these tags, consider a data table:
var dataTableDescendants = ["col", "colgroup", "tfoot", "thead", "th"];
var descendantExists = function(tag) {
return !!table.getElementsByTagName(tag)[0];
};
if (dataTableDescendants.some(descendantExists)) {
this.log("Data table because found data-y descendant");
table._readabilityDataTable = true;
continue;
}
// Nested tables indicate a layout table:
if (table.getElementsByTagName("table")[0]) {
table._readabilityDataTable = false;
continue;
}
var sizeInfo = this._getRowAndColumnCount(table);
if (sizeInfo.rows >= 10 || sizeInfo.columns > 4) {
table._readabilityDataTable = true;
continue;
}
// Now just go by size entirely:
table._readabilityDataTable = sizeInfo.rows * sizeInfo.columns > 10;
}
},
/**
* Clean an element of all tags of type "tag" if they look fishy.
* "Fishy" is an algorithm based on content length, classnames, link density, number of images & embeds, etc.
*
* @return void
**/
_cleanConditionally: function(e, tag) {
if (!this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY))
return;
var isList = tag === "ul" || tag === "ol";
// Gather counts for other typical elements embedded within.
// Traverse backwards so we can remove nodes at the same time
// without effecting the traversal.
//
// TODO: Consider taking into account original contentScore here.
this._removeNodes(e.getElementsByTagName(tag), function(node) {
// First check if we're in a data table, in which case don't remove us.
var isDataTable = function(t) {
return t._readabilityDataTable;
};
if (this._hasAncestorTag(node, "table", -1, isDataTable)) {
return false;
}
var weight = this._getClassWeight(node);
var contentScore = 0;
this.log("Cleaning Conditionally", node);
if (weight + contentScore < 0) {
return true;
}
if (this._getCharCount(node, ",") < 10) {
// If there are not very many commas, and the number of
// non-paragraph elements is more than paragraphs or other
// ominous signs, remove the element.
var p = node.getElementsByTagName("p").length;
var img = node.getElementsByTagName("img").length;
var li = node.getElementsByTagName("li").length - 100;
var input = node.getElementsByTagName("input").length;
var embedCount = 0;
var embeds = node.getElementsByTagName("embed");
for (var ei = 0, il = embeds.length; ei < il; ei += 1) {
if (!this.REGEXPS.videos.test(embeds[ei].src))
embedCount += 1;
}
var linkDensity = this._getLinkDensity(node);
var contentLength = this._getInnerText(node).length;
var haveToRemove =
(img > 1 && p / img < 0.5 && !this._hasAncestorTag(node, "figure")) ||
(!isList && li > p) ||
(input > Math.floor(p/3)) ||
(!isList && contentLength < 25 && (img === 0 || img > 2) && !this._hasAncestorTag(node, "figure")) ||
(!isList && weight < 25 && linkDensity > 0.2) ||
(weight >= 25 && linkDensity > 0.5) ||
((embedCount === 1 && contentLength < 75) || embedCount > 1);
return haveToRemove;
}
return false;
});
},
/**
* Clean out elements whose id/class combinations match specific string.
*
* @param Element
* @param RegExp match id/class combination.
* @return void
**/
_cleanMatchedNodes: function(e, regex) {
var endOfSearchMarkerNode = this._getNextNode(e, true);
var next = this._getNextNode(e);
while (next && next != endOfSearchMarkerNode) {
if (regex.test(next.className + " " + next.id)) {
next = this._removeAndGetNext(next);
} else {
next = this._getNextNode(next);
}
}
},
/**
* Clean out spurious headers from an Element. Checks things like classnames and link density.
*
* @param Element
* @return void
**/
_cleanHeaders: function(e) {
for (var headerIndex = 1; headerIndex < 3; headerIndex += 1) {
this._removeNodes(e.getElementsByTagName("h" + headerIndex), function (header) {
return this._getClassWeight(header) < 0;
});
}
},
_flagIsActive: function(flag) {
return (this._flags & flag) > 0;
},
_removeFlag: function(flag) {
this._flags = this._flags & ~flag;
},
_isProbablyVisible: function(node) {
return node.style.display != "none" && !node.hasAttribute("hidden");
},
/**
* 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);
}
if (!helperIsVisible) {
helperIsVisible = this._isProbablyVisible;
}
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");
}
}
// Remove script tags from the document.
this._removeScripts(this._doc);
this._prepDocument();
var metadata = this._getArticleMetadata();
this._articleTitle = metadata.title;
var articleContent = this._grabArticle();
if (!articleContent)
return null;
this.log("Grabbed: " + articleContent.innerHTML);
this._postProcessContent(articleContent);
// If we haven't found an excerpt in the article's metadata, use the article's
// first paragraph as the excerpt. This is used for displaying a preview of
// the article's content.
if (!metadata.excerpt) {
var paragraphs = articleContent.getElementsByTagName("p");
if (paragraphs.length > 0) {
metadata.excerpt = paragraphs[0].textContent.trim();
}
}
var textContent = articleContent.textContent;
return {
title: this._articleTitle,
byline: metadata.byline || this._articleByline,
dir: this._articleDir,
content: articleContent.innerHTML,
textContent: textContent,
length: textContent.length,
excerpt: metadata.excerpt,
};
}
};
if (typeof module === "object") {
module.exports = Readability;
}