readability-1/Readability.js at build-issues-node-js-update · httpsgithu/readability-1 · GitHub

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/*eslint-env es6:false*/

* 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._articleSiteName = null;

this._attempts = [];

// Configurable options

this._debug = !!options.debug;

this._maxElemsToParse = options.maxElemsToParse || this.DEFAULT_MAX_ELEMS_TO_PARSE;

this._nbTopCandidates = options.nbTopCandidates || this.DEFAULT_N_TOP_CANDIDATES;

this._charThreshold = options.charThreshold || this.DEFAULT_CHAR_THRESHOLD;

this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []);

// 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: {

// NOTE: These two regular expressions are duplicated in

// Readability-readerable.js. Please keep both copies in sync.

byline: /byline|author|dateline|writtenby|p-author/i,

replaceFonts: /<(\/?)font[^>]*>/gi,

normalize: /\s{2,}/g,

shareElements: /(\b|_)(share|sharedaddy)(\b|_)/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 = this._getAllNodesWithTag(articleContent, ["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 = this._getAllNodesWithTag(articleContent, ["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().replace(this.REGEXPS.normalize, " ");

// If we now have 4 words or fewer as our title, and either no

// 'hierarchical' separators (\, /, > or ») were found in the original

// title or we decreased the number of words by more than 1 word, use

// the original title.

var curTitleWordCount = wordCount(curTitle);

if (curTitleWordCount <= 4 &&

(!titleHadHierarchicalSeparators ||

curTitleWordCount != wordCount(origTitle.replace(/[\|\-\\\/>»]+/g, "")) - 1)) {

curTitle = origTitle;

}

return curTitle;

/**

* Prepare the HTML document for readability to scrape it.

* This includes things like stripping javascript, CSS, and handling terrible markup.

* @return void

**/

_prepDocument: function() {

var doc = this._doc;

// Remove all style tags in head

this._removeNodes(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 elements with a single .

* Whitespace between elements are ignored. For example:

* <div>foo bar abc</div>

* will become:

* <div>foo barabc</div>

_replaceBrs: function (elem) {

this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {

var next = br.nextSibling;

// Whether 2 or more elements have been found and replaced with a

// block.

var replaced = false;

// If we find a chain, remove the s until we hit another element

// or non-whitespace. This leaves behind the first in the chain

// (which will be replaced with a 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 chain, replace the remaining with a . Add

// all sibling nodes as children of the until we hit another

// chain.

if (replaced) {

var p = this._doc.createElement("p");

br.parentNode.replaceChild(p, br);

next = p.nextSibling;

while (next) {

// If we've hit another , we're done adding children to this .

if (next.tagName == "BR") {

var nextElem = this._nextElement(next.nextSibling);

if (nextElem && nextElem.tagName == "BR")

break;

}

if (!this._isPhrasingContent(next))

break;

// Otherwise, make this node a child of the new .

var sibling = next.nextSibling;

p.appendChild(next);

next = sibling;

}

while (p.lastChild && this._isWhitespace(p.lastChild)) {

p.removeChild(p.lastChild);

}

if (p.parentNode.tagName === "P")

this._setNodeTag(p.parentNode, "DIV");

}

});

_setNodeTag: function (node, tag) {

this.log("_setNodeTag", node, tag);

if (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++) {

try {

replacement.setAttribute(node.attributes[i].name, node.attributes[i].value);

} catch (ex) {

/* it's possible for setAttribute() to throw if the attribute name

* isn't a valid XML Name. Such attributes can however be parsed from

* source in HTML docs, see https://github.com/whatwg/html/issues/4275,

* so we can hit them here and then throw. We don't care about such

* attributes so we ignore them.

}

return replacement;

/**

* Prepare the article node for display. Clean out any inline styles,

* iframes, forms, strip extraneous tags, etc.

* @param Element

* @return void

**/

_prepArticle: function(articleContent) {

this._cleanStyles(articleContent);

// Check for data tables before we continue, to avoid removing items in

// those tables, which will often be isolated even though they're

// visually linked to other content-ful elements (text, images, etc.).

this._markDataTables(articleContent);

this._fixLazyImages(articleContent);

// Clean out junk from the article content

this._cleanConditionally(articleContent, "form");

this._cleanConditionally(articleContent, "fieldset");

this._clean(articleContent, "object");

this._clean(articleContent, "embed");

this._clean(articleContent, "h1");

this._clean(articleContent, "footer");

this._clean(articleContent, "link");

this._clean(articleContent, "aside");

// Clean out elements with little content that have "share" in their id/class combinations from final top candidates,

// which means we don't remove the top candidates even they have "share".

var shareElementThreshold = this.DEFAULT_CHAR_THRESHOLD;

this._forEachNode(articleContent.children, function (topCandidate) {

this._cleanMatchedNodes(topCandidate, function (node, matchString) {

return this.REGEXPS.shareElements.test(matchString) && node.textContent.length < shareElementThreshold;

});

// 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");

var itemprop = node.getAttribute("itemprop");

}

if ((rel === "author" || (itemprop && itemprop.indexOf("author") !== -1) || this.REGEXPS.byline.test(matchString)) && this._isValidByline(node.textContent)) {

this._articleByline = node.textContent.trim();

return true;

}

return false;

_getNodeAncestors: function(node, maxDepth) {

maxDepth = maxDepth || 0;

var i = 0, ancestors = [];

while (node.parentNode) {

ancestors.push(node.parentNode);

if (maxDepth && ++i === maxDepth)

break;

node = node.parentNode;

}

return ancestors;

/***

* grabArticle - Using a variety of metrics (content score, classname, element types), find the content that is

* most likely to be the stuff a user wants to read. Then return it wrapped up in a div.

* @param page a document to run upon. Needs to be a full document, complete with body.

* @return Element

**/

_grabArticle: function (page) {

this.log("**** grabArticle ****");

var doc = this._doc;

var isPaging = (page !== null ? 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) &&

!this._hasAncestorTag(node, "table") &&

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;

}

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readability-1/Readability.js at build-issues-node-js-update · httpsgithu/readability-1 · GitHub

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