web-fetcher-helper.js•105 kB
/* eslint-disable */
if (window.__WEB_FETCHER_HELPER_INITIALIZED__) {
// Already initialized, skip
} else {
window.__WEB_FETCHER_HELPER_INITIALIZED__ = true;
/*
* Copyright (c) 2010 Arc90 Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* This code is heavily based on Arc90's readability.js (1.7.1) script
* available at: http://code.google.com/p/arc90labs-readability
*/
/**
* Public constructor.
* @param {HTMLDocument} doc The document to parse.
* @param {Object} options The options object.
*/
function Readability(doc, options) {
// In some older versions, people passed a URI as the first argument. Cope:
if (options && options.documentElement) {
doc = options;
options = arguments[2];
} else if (!doc || !doc.documentElement) {
throw new Error('First argument to Readability constructor should be a document object.');
}
options = options || {};
this._doc = doc;
this._docJSDOMParser = this._doc.firstChild.__JSDOMParser__;
this._articleTitle = null;
this._articleByline = null;
this._articleDir = null;
this._articleSiteName = null;
this._attempts = [];
this._metadata = {};
// Configurable options
this._debug = !!options.debug;
this._maxElemsToParse = options.maxElemsToParse || this.DEFAULT_MAX_ELEMS_TO_PARSE;
this._nbTopCandidates = options.nbTopCandidates || this.DEFAULT_N_TOP_CANDIDATES;
this._charThreshold = options.charThreshold || this.DEFAULT_CHAR_THRESHOLD;
this._classesToPreserve = this.CLASSES_TO_PRESERVE.concat(options.classesToPreserve || []);
this._keepClasses = !!options.keepClasses;
this._serializer =
options.serializer ||
function (el) {
return el.innerHTML;
};
this._disableJSONLD = !!options.disableJSONLD;
this._allowedVideoRegex = options.allowedVideoRegex || this.REGEXPS.videos;
this._linkDensityModifier = options.linkDensityModifier || 0;
// Start with all flags set
this._flags =
this.FLAG_STRIP_UNLIKELYS | this.FLAG_WEIGHT_CLASSES | this.FLAG_CLEAN_CONDITIONALLY;
// Control whether log messages are sent to the console
if (this._debug) {
let logNode = function (node) {
if (node.nodeType == node.TEXT_NODE) {
return `${node.nodeName} ("${node.textContent}")`;
}
let attrPairs = Array.from(node.attributes || [], function (attr) {
return `${attr.name}="${attr.value}"`;
}).join(' ');
return `<${node.localName} ${attrPairs}>`;
};
this.log = function () {
if (typeof console !== 'undefined') {
let args = Array.from(arguments, (arg) => {
if (arg && arg.nodeType == this.ELEMENT_NODE) {
return logNode(arg);
}
return arg;
});
args.unshift('Reader: (Readability)');
// Debug logging removed
} else if (typeof dump !== 'undefined') {
/* global dump */
var msg = Array.prototype.map
.call(arguments, function (x) {
return x && x.nodeName ? logNode(x) : x;
})
.join(' ');
dump('Reader: (Readability) ' + msg + '\n');
}
};
} else {
this.log = function () {};
}
}
Readability.prototype = {
FLAG_STRIP_UNLIKELYS: 0x1,
FLAG_WEIGHT_CLASSES: 0x2,
FLAG_CLEAN_CONDITIONALLY: 0x4,
// https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
ELEMENT_NODE: 1,
TEXT_NODE: 3,
// Max number of nodes supported by this parser. Default: 0 (no limit)
DEFAULT_MAX_ELEMS_TO_PARSE: 0,
// The number of top candidates to consider when analysing how
// tight the competition is among candidates.
DEFAULT_N_TOP_CANDIDATES: 5,
// Element tags to score by default.
DEFAULT_TAGS_TO_SCORE: 'section,h2,h3,h4,h5,h6,p,td,pre'.toUpperCase().split(','),
// The default number of chars an article must have in order to return a result
DEFAULT_CHAR_THRESHOLD: 500,
// All of the regular expressions in use within readability.
// Defined up here so we don't instantiate them repeatedly in loops.
REGEXPS: {
// NOTE: These two regular expressions are duplicated in
// Readability-readerable.js. Please keep both copies in sync.
unlikelyCandidates:
/-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i,
okMaybeItsACandidate: /and|article|body|column|content|main|shadow/i,
positive:
/article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story/i,
negative:
/-ad-|hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|footer|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|widget/i,
extraneous:
/print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i,
byline: /byline|author|dateline|writtenby|p-author/i,
replaceFonts: /<(\/?)font[^>]*>/gi,
normalize: /\s{2,}/g,
videos:
/\/\/(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)/i,
shareElements: /(\b|_)(share|sharedaddy)(\b|_)/i,
nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i,
prevLink: /(prev|earl|old|new|<|«)/i,
tokenize: /\W+/g,
whitespace: /^\s*$/,
hasContent: /\S$/,
hashUrl: /^#.+/,
srcsetUrl: /(\S+)(\s+[\d.]+[xw])?(\s*(?:,|$))/g,
b64DataUrl: /^data:\s*([^\s;,]+)\s*;\s*base64\s*,/i,
// Commas as used in Latin, Sindhi, Chinese and various other scripts.
// see: https://en.wikipedia.org/wiki/Comma#Comma_variants
commas: /\u002C|\u060C|\uFE50|\uFE10|\uFE11|\u2E41|\u2E34|\u2E32|\uFF0C/g,
// See: https://schema.org/Article
jsonLdArticleTypes:
/^Article|AdvertiserContentArticle|NewsArticle|AnalysisNewsArticle|AskPublicNewsArticle|BackgroundNewsArticle|OpinionNewsArticle|ReportageNewsArticle|ReviewNewsArticle|Report|SatiricalArticle|ScholarlyArticle|MedicalScholarlyArticle|SocialMediaPosting|BlogPosting|LiveBlogPosting|DiscussionForumPosting|TechArticle|APIReference$/,
// used to see if a node's content matches words commonly used for ad blocks or loading indicators
adWords: /^(ad(vertising|vertisement)?|pub(licité)?|werb(ung)?|广告|Реклама|Anuncio)$/iu,
loadingWords: /^((loading|正在加载|Загрузка|chargement|cargando)(…|\.\.\.)?)$/iu,
},
UNLIKELY_ROLES: [
'menu',
'menubar',
'complementary',
'navigation',
'alert',
'alertdialog',
'dialog',
],
DIV_TO_P_ELEMS: new Set(['BLOCKQUOTE', 'DL', 'DIV', 'IMG', 'OL', 'P', 'PRE', 'TABLE', 'UL']),
ALTER_TO_DIV_EXCEPTIONS: ['DIV', 'ARTICLE', 'SECTION', 'P', 'OL', 'UL'],
PRESENTATIONAL_ATTRIBUTES: [
'align',
'background',
'bgcolor',
'border',
'cellpadding',
'cellspacing',
'frame',
'hspace',
'rules',
'style',
'valign',
'vspace',
],
DEPRECATED_SIZE_ATTRIBUTE_ELEMS: ['TABLE', 'TH', 'TD', 'HR', 'PRE'],
// The commented out elements qualify as phrasing content but tend to be
// removed by readability when put into paragraphs, so we ignore them here.
PHRASING_ELEMS: [
// "CANVAS", "IFRAME", "SVG", "VIDEO",
'ABBR',
'AUDIO',
'B',
'BDO',
'BR',
'BUTTON',
'CITE',
'CODE',
'DATA',
'DATALIST',
'DFN',
'EM',
'EMBED',
'I',
'IMG',
'INPUT',
'KBD',
'LABEL',
'MARK',
'MATH',
'METER',
'NOSCRIPT',
'OBJECT',
'OUTPUT',
'PROGRESS',
'Q',
'RUBY',
'SAMP',
'SCRIPT',
'SELECT',
'SMALL',
'SPAN',
'STRONG',
'SUB',
'SUP',
'TEXTAREA',
'TIME',
'VAR',
'WBR',
],
// These are the classes that readability sets itself.
CLASSES_TO_PRESERVE: ['page'],
// These are the list of HTML entities that need to be escaped.
HTML_ESCAPE_MAP: {
lt: '<',
gt: '>',
amp: '&',
quot: '"',
apos: "'",
},
/**
* Run any post-process modifications to article content as necessary.
*
* @param Element
* @return void
**/
_postProcessContent(articleContent) {
// Readability cannot open relative uris so we convert them to absolute uris.
this._fixRelativeUris(articleContent);
this._simplifyNestedElements(articleContent);
if (!this._keepClasses) {
// Remove classes.
this._cleanClasses(articleContent);
}
},
/**
* Iterates over a NodeList, calls `filterFn` for each node and removes node
* if function returned `true`.
*
* If function is not passed, removes all the nodes in node list.
*
* @param NodeList nodeList The nodes to operate on
* @param Function filterFn the function to use as a filter
* @return void
*/
_removeNodes(nodeList, filterFn) {
// Avoid ever operating on live node lists.
if (this._docJSDOMParser && nodeList._isLiveNodeList) {
throw new Error('Do not pass live node lists to _removeNodes');
}
for (var i = nodeList.length - 1; i >= 0; i--) {
var node = nodeList[i];
var parentNode = node.parentNode;
if (parentNode) {
if (!filterFn || filterFn.call(this, node, i, nodeList)) {
parentNode.removeChild(node);
}
}
}
},
/**
* Iterates over a NodeList, and calls _setNodeTag for each node.
*
* @param NodeList nodeList The nodes to operate on
* @param String newTagName the new tag name to use
* @return void
*/
_replaceNodeTags(nodeList, newTagName) {
// Avoid ever operating on live node lists.
if (this._docJSDOMParser && nodeList._isLiveNodeList) {
throw new Error('Do not pass live node lists to _replaceNodeTags');
}
for (const node of nodeList) {
this._setNodeTag(node, newTagName);
}
},
/**
* Iterate over a NodeList, which doesn't natively fully implement the Array
* interface.
*
* For convenience, the current object context is applied to the provided
* iterate function.
*
* @param NodeList nodeList The NodeList.
* @param Function fn The iterate function.
* @return void
*/
_forEachNode(nodeList, fn) {
Array.prototype.forEach.call(nodeList, fn, this);
},
/**
* Iterate over a NodeList, and return the first node that passes
* the supplied test function
*
* For convenience, the current object context is applied to the provided
* test function.
*
* @param NodeList nodeList The NodeList.
* @param Function fn The test function.
* @return void
*/
_findNode(nodeList, fn) {
return Array.prototype.find.call(nodeList, fn, this);
},
/**
* Iterate over a NodeList, return true if any of the provided iterate
* function calls returns true, false otherwise.
*
* For convenience, the current object context is applied to the
* provided iterate function.
*
* @param NodeList nodeList The NodeList.
* @param Function fn The iterate function.
* @return Boolean
*/
_someNode(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(nodeList, fn) {
return Array.prototype.every.call(nodeList, fn, this);
},
_getAllNodesWithTag(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(node) {
var classesToPreserve = this._classesToPreserve;
var className = (node.getAttribute('class') || '')
.split(/\s+/)
.filter((cls) => classesToPreserve.includes(cls))
.join(' ');
if (className) {
node.setAttribute('class', className);
} else {
node.removeAttribute('class');
}
for (node = node.firstElementChild; node; node = node.nextElementSibling) {
this._cleanClasses(node);
}
},
/**
* Tests whether a string is a URL or not.
*
* @param {string} str The string to test
* @return {boolean} true if str is a URL, false if not
*/
_isUrl(str) {
try {
new URL(str);
return true;
} catch {
return false;
}
},
/**
* Converts each <a> and <img> uri in the given element to an absolute URI,
* ignoring #ref URIs.
*
* @param Element
* @return void
*/
_fixRelativeUris(articleContent) {
var baseURI = this._doc.baseURI;
var documentURI = this._doc.documentURI;
function toAbsoluteURI(uri) {
// Leave hash links alone if the base URI matches the document URI:
if (baseURI == documentURI && uri.charAt(0) == '#') {
return uri;
}
// Otherwise, resolve against base URI:
try {
return new URL(uri, baseURI).href;
} catch (ex) {
// Something went wrong, just return the original:
}
return uri;
}
var links = this._getAllNodesWithTag(articleContent, ['a']);
this._forEachNode(links, function (link) {
var href = link.getAttribute('href');
if (href) {
// Remove links with javascript: URIs, since
// they won't work after scripts have been removed from the page.
if (href.indexOf('javascript:') === 0) {
// if the link only contains simple text content, it can be converted to a text node
if (link.childNodes.length === 1 && link.childNodes[0].nodeType === this.TEXT_NODE) {
var text = this._doc.createTextNode(link.textContent);
link.parentNode.replaceChild(text, link);
} else {
// if the link has multiple children, they should all be preserved
var container = this._doc.createElement('span');
while (link.firstChild) {
container.appendChild(link.firstChild);
}
link.parentNode.replaceChild(container, link);
}
} else {
link.setAttribute('href', toAbsoluteURI(href));
}
}
});
var medias = this._getAllNodesWithTag(articleContent, [
'img',
'picture',
'figure',
'video',
'audio',
'source',
]);
this._forEachNode(medias, function (media) {
var src = media.getAttribute('src');
var poster = media.getAttribute('poster');
var srcset = media.getAttribute('srcset');
if (src) {
media.setAttribute('src', toAbsoluteURI(src));
}
if (poster) {
media.setAttribute('poster', toAbsoluteURI(poster));
}
if (srcset) {
var newSrcset = srcset.replace(this.REGEXPS.srcsetUrl, function (_, p1, p2, p3) {
return toAbsoluteURI(p1) + (p2 || '') + p3;
});
media.setAttribute('srcset', newSrcset);
}
});
},
_simplifyNestedElements(articleContent) {
var node = articleContent;
while (node) {
if (
node.parentNode &&
['DIV', 'SECTION'].includes(node.tagName) &&
!(node.id && node.id.startsWith('readability'))
) {
if (this._isElementWithoutContent(node)) {
node = this._removeAndGetNext(node);
continue;
} else if (
this._hasSingleTagInsideElement(node, 'DIV') ||
this._hasSingleTagInsideElement(node, 'SECTION')
) {
var child = node.children[0];
for (var i = 0; i < node.attributes.length; i++) {
child.setAttributeNode(node.attributes[i].cloneNode());
}
node.parentNode.replaceChild(child, node);
node = child;
continue;
}
}
node = this._getNextNode(node);
}
},
/**
* Get the article title as an H1.
*
* @return string
**/
_getArticleTitle() {
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);
let allSeparators = Array.from(origTitle.matchAll(/ [\|\-\\\/>»] /gi));
curTitle = origTitle.substring(0, allSeparators.pop().index);
// If the resulting title is too short, remove the first part instead:
if (wordCount(curTitle) < 3) {
curTitle = origTitle.replace(/^[^\|\-\\\/>»]*[\|\-\\\/>»]/gi, '');
}
} else if (curTitle.includes(': ')) {
// Check if we have an heading containing this exact string, so we
// could assume it's the full title.
var headings = this._getAllNodesWithTag(doc, ['h1', '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() {
var doc = this._doc;
// Remove all style tags in head
this._removeNodes(this._getAllNodesWithTag(doc, ['style']));
if (doc.body) {
this._replaceBrs(doc.body);
}
this._replaceNodeTags(this._getAllNodesWithTag(doc, ['font']), 'SPAN');
},
/**
* Finds the next node, starting from the given node, and ignoring
* whitespace in between. If the given node is an element, the same node is
* returned.
*/
_nextNode(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(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 node
// or non-whitespace. This leaves behind the first <br> in the chain
// (which will be replaced with a <p> later).
while ((next = this._nextNode(next)) && next.tagName == 'BR') {
replaced = true;
var brSibling = next.nextSibling;
next.remove();
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._nextNode(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.lastChild.remove();
}
if (p.parentNode.tagName === 'P') {
this._setNodeTag(p.parentNode, 'DIV');
}
}
});
},
_setNodeTag(node, tag) {
this.log('_setNodeTag', node, tag);
if (this._docJSDOMParser) {
node.localName = tag.toLowerCase();
node.tagName = tag.toUpperCase();
return node;
}
var replacement = node.ownerDocument.createElement(tag);
while (node.firstChild) {
replacement.appendChild(node.firstChild);
}
node.parentNode.replaceChild(replacement, node);
if (node.readability) {
replacement.readability = node.readability;
}
for (var i = 0; i < node.attributes.length; i++) {
replacement.setAttributeNode(node.attributes[i].cloneNode());
}
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(articleContent) {
this._cleanStyles(articleContent);
// Check for data tables before we continue, to avoid removing items in
// those tables, which will often be isolated even though they're
// visually linked to other content-ful elements (text, images, etc.).
this._markDataTables(articleContent);
this._fixLazyImages(articleContent);
// Clean out junk from the article content
this._cleanConditionally(articleContent, 'form');
this._cleanConditionally(articleContent, 'fieldset');
this._clean(articleContent, 'object');
this._clean(articleContent, 'embed');
this._clean(articleContent, 'footer');
this._clean(articleContent, 'link');
this._clean(articleContent, 'aside');
// Clean out elements with little content that have "share" in their id/class combinations from final top candidates,
// which means we don't remove the top candidates even they have "share".
var shareElementThreshold = this.DEFAULT_CHAR_THRESHOLD;
this._forEachNode(articleContent.children, function (topCandidate) {
this._cleanMatchedNodes(topCandidate, function (node, matchString) {
return (
this.REGEXPS.shareElements.test(matchString) &&
node.textContent.length < shareElementThreshold
);
});
});
this._clean(articleContent, 'iframe');
this._clean(articleContent, 'input');
this._clean(articleContent, 'textarea');
this._clean(articleContent, 'select');
this._clean(articleContent, 'button');
this._cleanHeaders(articleContent);
// Do these last as the previous stuff may have removed junk
// that will affect these
this._cleanConditionally(articleContent, 'table');
this._cleanConditionally(articleContent, 'ul');
this._cleanConditionally(articleContent, 'div');
// replace H1 with H2 as H1 should be only title that is displayed separately
this._replaceNodeTags(this._getAllNodesWithTag(articleContent, ['h1']), 'h2');
// Remove extra paragraphs
this._removeNodes(this._getAllNodesWithTag(articleContent, ['p']), function (paragraph) {
// At this point, nasty iframes have been removed; only embedded video
// ones remain.
var contentElementCount = this._getAllNodesWithTag(paragraph, [
'img',
'embed',
'object',
'iframe',
]).length;
return contentElementCount === 0 && !this._getInnerText(paragraph, false);
});
this._forEachNode(this._getAllNodesWithTag(articleContent, ['br']), function (br) {
var next = this._nextNode(br.nextSibling);
if (next && next.tagName == 'P') {
br.remove();
}
});
// 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(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(node) {
var nextNode = this._getNextNode(node, true);
node.remove();
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.
*
* @param {Element} node
* @param {boolean} ignoreSelfAndKids
* @return {Element}
*/
_getNextNode(node, ignoreSelfAndKids) {
// First check for kids if those aren't being ignored
if (!ignoreSelfAndKids && node.firstElementChild) {
return node.firstElementChild;
}
// Then for siblings...
if (node.nextElementSibling) {
return node.nextElementSibling;
}
// And finally, move up the parent chain *and* find a sibling
// (because this is depth-first traversal, we will have already
// seen the parent nodes themselves).
do {
node = node.parentNode;
} while (node && !node.nextElementSibling);
return node && node.nextElementSibling;
},
// compares second text to first one
// 1 = same text, 0 = completely different text
// works the way that it splits both texts into words and then finds words that are unique in second text
// the result is given by the lower length of unique parts
_textSimilarity(textA, textB) {
var tokensA = textA.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
var tokensB = textB.toLowerCase().split(this.REGEXPS.tokenize).filter(Boolean);
if (!tokensA.length || !tokensB.length) {
return 0;
}
var uniqTokensB = tokensB.filter((token) => !tokensA.includes(token));
var distanceB = uniqTokensB.join(' ').length / tokensB.join(' ').length;
return 1 - distanceB;
},
/**
* Checks whether an element node contains a valid byline
*
* @param node {Element}
* @param matchString {string}
* @return boolean
*/
_isValidByline(node, matchString) {
var rel = node.getAttribute('rel');
var itemprop = node.getAttribute('itemprop');
var bylineLength = node.textContent.trim().length;
return (
(rel === 'author' ||
(itemprop && itemprop.includes('author')) ||
this.REGEXPS.byline.test(matchString)) &&
!!bylineLength &&
bylineLength < 100
);
},
_getNodeAncestors(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(page) {
this.log('**** grabArticle ****');
var doc = this._doc;
var isPaging = page !== null;
page = page ? page : this._doc.body;
// We can't grab an article if we don't have a page!
if (!page) {
this.log('No body found in document. Abort.');
return null;
}
var pageCacheHtml = page.innerHTML;
while (true) {
this.log('Starting grabArticle loop');
var stripUnlikelyCandidates = this._flagIsActive(this.FLAG_STRIP_UNLIKELYS);
// First, node prepping. Trash nodes that look cruddy (like ones with the
// class name "comment", etc), and turn divs into P tags where they have been
// used inappropriately (as in, where they contain no other block level elements.)
var elementsToScore = [];
var node = this._doc.documentElement;
let shouldRemoveTitleHeader = true;
while (node) {
if (node.tagName === 'HTML') {
this._articleLang = node.getAttribute('lang');
}
var matchString = node.className + ' ' + node.id;
if (!this._isProbablyVisible(node)) {
this.log('Removing hidden node - ' + matchString);
node = this._removeAndGetNext(node);
continue;
}
// User is not able to see elements applied with both "aria-modal = true" and "role = dialog"
if (node.getAttribute('aria-modal') == 'true' && node.getAttribute('role') == 'dialog') {
node = this._removeAndGetNext(node);
continue;
}
// If we don't have a byline yet check to see if this node is a byline; if it is store the byline and remove the node.
if (
!this._articleByline &&
!this._metadata.byline &&
this._isValidByline(node, matchString)
) {
// Find child node matching [itemprop="name"] and use that if it exists for a more accurate author name byline
var endOfSearchMarkerNode = this._getNextNode(node, true);
var next = this._getNextNode(node);
var itemPropNameNode = null;
while (next && next != endOfSearchMarkerNode) {
var itemprop = next.getAttribute('itemprop');
if (itemprop && itemprop.includes('name')) {
itemPropNameNode = next;
break;
} else {
next = this._getNextNode(next);
}
}
this._articleByline = (itemPropNameNode ?? node).textContent.trim();
node = this._removeAndGetNext(node);
continue;
}
if (shouldRemoveTitleHeader && this._headerDuplicatesTitle(node)) {
this.log('Removing header: ', node.textContent.trim(), this._articleTitle.trim());
shouldRemoveTitleHeader = false;
node = this._removeAndGetNext(node);
continue;
}
// Remove unlikely candidates
if (stripUnlikelyCandidates) {
if (
this.REGEXPS.unlikelyCandidates.test(matchString) &&
!this.REGEXPS.okMaybeItsACandidate.test(matchString) &&
!this._hasAncestorTag(node, 'table') &&
!this._hasAncestorTag(node, 'code') &&
node.tagName !== 'BODY' &&
node.tagName !== 'A'
) {
this.log('Removing unlikely candidate - ' + matchString);
node = this._removeAndGetNext(node);
continue;
}
if (this.UNLIKELY_ROLES.includes(node.getAttribute('role'))) {
this.log(
'Removing content with role ' + node.getAttribute('role') + ' - ' + matchString,
);
node = this._removeAndGetNext(node);
continue;
}
}
// Remove DIV, SECTION, and HEADER nodes without any content(e.g. text, image, video, or iframe).
if (
(node.tagName === 'DIV' ||
node.tagName === 'SECTION' ||
node.tagName === 'HEADER' ||
node.tagName === 'H1' ||
node.tagName === 'H2' ||
node.tagName === 'H3' ||
node.tagName === 'H4' ||
node.tagName === 'H5' ||
node.tagName === 'H6') &&
this._isElementWithoutContent(node)
) {
node = this._removeAndGetNext(node);
continue;
}
if (this.DEFAULT_TAGS_TO_SCORE.includes(node.tagName)) {
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.lastChild.remove();
}
p = null;
}
childNode = nextSibling;
}
// Sites like http://mobile.slate.com encloses each paragraph with a DIV
// element. DIVs with only a P element inside and no text content can be
// safely converted into plain P elements to avoid confusing the scoring
// algorithm with DIVs with are, in practice, paragraphs.
if (this._hasSingleTagInsideElement(node, 'P') && this._getLinkDensity(node) < 0.25) {
var newNode = node.children[0];
node.parentNode.replaceChild(newNode, node);
node = newNode;
elementsToScore.push(node);
} else if (!this._hasChildBlockElement(node)) {
node = this._setNodeTag(node, 'P');
elementsToScore.push(node);
}
}
node = this._getNextNode(node);
}
/**
* Loop through all paragraphs, and assign a score to them based on how content-y they look.
* Then add their score to their parent node.
*
* A score is determined by things like number of commas, class names, etc. Maybe eventually link density.
**/
var candidates = [];
this._forEachNode(elementsToScore, function (elementToScore) {
if (
!elementToScore.parentNode ||
typeof elementToScore.parentNode.tagName === 'undefined'
) {
return;
}
// If this paragraph is less than 25 characters, don't even count it.
var innerText = this._getInnerText(elementToScore);
if (innerText.length < 25) {
return;
}
// Exclude nodes with no ancestor.
var ancestors = this._getNodeAncestors(elementToScore, 5);
if (ancestors.length === 0) {
return;
}
var contentScore = 0;
// Add a point for the paragraph itself as a base.
contentScore += 1;
// Add points for any commas within this paragraph.
contentScore += innerText.split(this.REGEXPS.commas).length;
// For every 100 characters in this paragraph, add another point. Up to 3 points.
contentScore += Math.min(Math.floor(innerText.length / 100), 3);
// Initialize and score ancestors.
this._forEachNode(ancestors, function (ancestor, level) {
if (
!ancestor.tagName ||
!ancestor.parentNode ||
typeof ancestor.parentNode.tagName === 'undefined'
) {
return;
}
if (typeof ancestor.readability === 'undefined') {
this._initializeNode(ancestor);
candidates.push(ancestor);
}
// Node score divider:
// - parent: 1 (no division)
// - grandparent: 2
// - great grandparent+: ancestor level * 3
if (level === 0) {
var scoreDivider = 1;
} else if (level === 1) {
scoreDivider = 2;
} else {
scoreDivider = level * 3;
}
ancestor.readability.contentScore += contentScore / scoreDivider;
});
});
// After we've calculated scores, loop through all of the possible
// candidate nodes we found and find the one with the highest score.
var topCandidates = [];
for (var c = 0, cl = candidates.length; c < cl; c += 1) {
var candidate = candidates[c];
// Scale the final candidates score based on link density. Good content
// should have a relatively small link density (5% or less) and be mostly
// unaffected by this operation.
var candidateScore =
candidate.readability.contentScore * (1 - this._getLinkDensity(candidate));
candidate.readability.contentScore = candidateScore;
this.log('Candidate:', candidate, 'with score ' + candidateScore);
for (var t = 0; t < this._nbTopCandidates; t++) {
var aTopCandidate = topCandidates[t];
if (!aTopCandidate || candidateScore > aTopCandidate.readability.contentScore) {
topCandidates.splice(t, 0, candidate);
if (topCandidates.length > this._nbTopCandidates) {
topCandidates.pop();
}
break;
}
}
}
var topCandidate = topCandidates[0] || null;
var neededToCreateTopCandidate = false;
var parentOfTopCandidate;
// If we still have no top candidate, just use the body as a last resort.
// We also have to copy the body node so it is something we can modify.
if (topCandidate === null || topCandidate.tagName === 'BODY') {
// Move all of the page's children into topCandidate
topCandidate = doc.createElement('DIV');
neededToCreateTopCandidate = true;
// Move everything (not just elements, also text nodes etc.) into the container
// so we even include text directly in the body:
while (page.firstChild) {
this.log('Moving child out:', page.firstChild);
topCandidate.appendChild(page.firstChild);
}
page.appendChild(topCandidate);
this._initializeNode(topCandidate);
} else if (topCandidate) {
// Find a better top candidate node if it contains (at least three) nodes which belong to `topCandidates` array
// and whose scores are quite closed with current `topCandidate` node.
var alternativeCandidateAncestors = [];
for (var i = 1; i < topCandidates.length; i++) {
if (
topCandidates[i].readability.contentScore / topCandidate.readability.contentScore >=
0.75
) {
alternativeCandidateAncestors.push(this._getNodeAncestors(topCandidates[i]));
}
}
var MINIMUM_TOPCANDIDATES = 3;
if (alternativeCandidateAncestors.length >= MINIMUM_TOPCANDIDATES) {
parentOfTopCandidate = topCandidate.parentNode;
while (parentOfTopCandidate.tagName !== 'BODY') {
var listsContainingThisAncestor = 0;
for (
var ancestorIndex = 0;
ancestorIndex < alternativeCandidateAncestors.length &&
listsContainingThisAncestor < MINIMUM_TOPCANDIDATES;
ancestorIndex++
) {
listsContainingThisAncestor += Number(
alternativeCandidateAncestors[ancestorIndex].includes(parentOfTopCandidate),
);
}
if (listsContainingThisAncestor >= MINIMUM_TOPCANDIDATES) {
topCandidate = parentOfTopCandidate;
break;
}
parentOfTopCandidate = parentOfTopCandidate.parentNode;
}
}
if (!topCandidate.readability) {
this._initializeNode(topCandidate);
}
// Because of our bonus system, parents of candidates might have scores
// themselves. They get half of the node. There won't be nodes with higher
// scores than our topCandidate, but if we see the score going *up* in the first
// few steps up the tree, that's a decent sign that there might be more content
// lurking in other places that we want to unify in. The sibling stuff
// below does some of that - but only if we've looked high enough up the DOM
// tree.
parentOfTopCandidate = topCandidate.parentNode;
var lastScore = topCandidate.readability.contentScore;
// The scores shouldn't get too low.
var scoreThreshold = lastScore / 3;
while (parentOfTopCandidate.tagName !== 'BODY') {
if (!parentOfTopCandidate.readability) {
parentOfTopCandidate = parentOfTopCandidate.parentNode;
continue;
}
var parentScore = parentOfTopCandidate.readability.contentScore;
if (parentScore < scoreThreshold) {
break;
}
if (parentScore > lastScore) {
// Alright! We found a better parent to use.
topCandidate = parentOfTopCandidate;
break;
}
lastScore = parentOfTopCandidate.readability.contentScore;
parentOfTopCandidate = parentOfTopCandidate.parentNode;
}
// If the top candidate is the only child, use parent instead. This will help sibling
// joining logic when adjacent content is actually located in parent's sibling node.
parentOfTopCandidate = topCandidate.parentNode;
while (
parentOfTopCandidate.tagName != 'BODY' &&
parentOfTopCandidate.children.length == 1
) {
topCandidate = parentOfTopCandidate;
parentOfTopCandidate = topCandidate.parentNode;
}
if (!topCandidate.readability) {
this._initializeNode(topCandidate);
}
}
// Now that we have the top candidate, look through its siblings for content
// that might also be related. Things like preambles, content split by ads
// that we removed, etc.
var articleContent = doc.createElement('DIV');
if (isPaging) {
articleContent.id = 'readability-content';
}
var siblingScoreThreshold = Math.max(10, topCandidate.readability.contentScore * 0.2);
// Keep potential top candidate's parent node to try to get text direction of it later.
parentOfTopCandidate = topCandidate.parentNode;
var siblings = parentOfTopCandidate.children;
for (var s = 0, sl = siblings.length; s < sl; s++) {
var sibling = siblings[s];
var append = false;
this.log(
'Looking at sibling node:',
sibling,
sibling.readability ? 'with score ' + sibling.readability.contentScore : '',
);
this.log(
'Sibling has score',
sibling.readability ? sibling.readability.contentScore : 'Unknown',
);
if (sibling === topCandidate) {
append = true;
} else {
var contentBonus = 0;
// Give a bonus if sibling nodes and top candidates have the example same classname
if (sibling.className === topCandidate.className && topCandidate.className !== '') {
contentBonus += topCandidate.readability.contentScore * 0.2;
}
if (
sibling.readability &&
sibling.readability.contentScore + contentBonus >= siblingScoreThreshold
) {
append = true;
} else if (sibling.nodeName === 'P') {
var linkDensity = this._getLinkDensity(sibling);
var nodeContent = this._getInnerText(sibling);
var nodeLength = nodeContent.length;
if (nodeLength > 80 && linkDensity < 0.25) {
append = true;
} else if (
nodeLength < 80 &&
nodeLength > 0 &&
linkDensity === 0 &&
nodeContent.search(/\.( |$)/) !== -1
) {
append = true;
}
}
}
if (append) {
this.log('Appending node:', sibling);
if (!this.ALTER_TO_DIV_EXCEPTIONS.includes(sibling.nodeName)) {
// We have a node that isn't a common block level element, like a form or td tag.
// Turn it into a div so it doesn't get filtered out later by accident.
this.log('Altering sibling:', sibling, 'to div.');
sibling = this._setNodeTag(sibling, 'DIV');
}
articleContent.appendChild(sibling);
// Fetch children again to make it compatible
// with DOM parsers without live collection support.
siblings = parentOfTopCandidate.children;
// siblings is a reference to the children array, and
// sibling is removed from the array when we call appendChild().
// As a result, we must revisit this index since the nodes
// have been shifted.
s -= 1;
sl -= 1;
}
}
if (this._debug) {
this.log('Article content pre-prep: ' + articleContent.innerHTML);
}
// So we have all of the content that we need. Now we clean it up for presentation.
this._prepArticle(articleContent);
if (this._debug) {
this.log('Article content post-prep: ' + articleContent.innerHTML);
}
if (neededToCreateTopCandidate) {
// We already created a fake div thing, and there wouldn't have been any siblings left
// for the previous loop, so there's no point trying to create a new div, and then
// move all the children over. Just assign IDs and class names here. No need to append
// because that already happened anyway.
topCandidate.id = 'readability-page-1';
topCandidate.className = 'page';
} else {
var div = doc.createElement('DIV');
div.id = 'readability-page-1';
div.className = 'page';
while (articleContent.firstChild) {
div.appendChild(articleContent.firstChild);
}
articleContent.appendChild(div);
}
if (this._debug) {
this.log('Article content after paging: ' + articleContent.innerHTML);
}
var parseSuccessful = true;
// Now that we've gone through the full algorithm, check to see if
// we got any meaningful content. If we didn't, we may need to re-run
// grabArticle with different flags set. This gives us a higher likelihood of
// finding the content, and the sieve approach gives us a higher likelihood of
// finding the -right- content.
var textLength = this._getInnerText(articleContent, true).length;
if (textLength < this._charThreshold) {
parseSuccessful = false;
// eslint-disable-next-line no-unsanitized/property
page.innerHTML = pageCacheHtml;
this._attempts.push({
articleContent,
textLength,
});
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 {
// No luck after removing flags, just return the longest text we found during the different loops
this._attempts.sort(function (a, b) {
return b.textLength - a.textLength;
});
// But first check if we actually have something
if (!this._attempts[0].textLength) {
return null;
}
articleContent = this._attempts[0].articleContent;
parseSuccessful = true;
}
}
if (parseSuccessful) {
// Find out text direction from ancestors of final top candidate.
var ancestors = [parentOfTopCandidate, topCandidate].concat(
this._getNodeAncestors(parentOfTopCandidate),
);
this._someNode(ancestors, function (ancestor) {
if (!ancestor.tagName) {
return false;
}
var articleDir = ancestor.getAttribute('dir');
if (articleDir) {
this._articleDir = articleDir;
return true;
}
return false;
});
return articleContent;
}
}
},
/**
* Converts some of the common HTML entities in string to their corresponding characters.
*
* @param str {string} - a string to unescape.
* @return string without HTML entity.
*/
_unescapeHtmlEntities(str) {
if (!str) {
return str;
}
var htmlEscapeMap = this.HTML_ESCAPE_MAP;
return str
.replace(/&(quot|amp|apos|lt|gt);/g, function (_, tag) {
return htmlEscapeMap[tag];
})
.replace(/&#(?:x([0-9a-f]+)|([0-9]+));/gi, function (_, hex, numStr) {
var num = parseInt(hex || numStr, hex ? 16 : 10);
// these character references are replaced by a conforming HTML parser
if (num == 0 || num > 0x10ffff || (num >= 0xd800 && num <= 0xdfff)) {
num = 0xfffd;
}
return String.fromCodePoint(num);
});
},
/**
* Try to extract metadata from JSON-LD object.
* For now, only Schema.org objects of type Article or its subtypes are supported.
* @return Object with any metadata that could be extracted (possibly none)
*/
_getJSONLD(doc) {
var scripts = this._getAllNodesWithTag(doc, ['script']);
var metadata;
this._forEachNode(scripts, function (jsonLdElement) {
if (!metadata && jsonLdElement.getAttribute('type') === 'application/ld+json') {
try {
// Strip CDATA markers if present
var content = jsonLdElement.textContent.replace(/^\s*<!\[CDATA\[|\]\]>\s*$/g, '');
var parsed = JSON.parse(content);
if (Array.isArray(parsed)) {
parsed = parsed.find((it) => {
return it['@type'] && it['@type'].match(this.REGEXPS.jsonLdArticleTypes);
});
if (!parsed) {
return;
}
}
var schemaDotOrgRegex = /^https?\:\/\/schema\.org\/?$/;
var matches =
(typeof parsed['@context'] === 'string' &&
parsed['@context'].match(schemaDotOrgRegex)) ||
(typeof parsed['@context'] === 'object' &&
typeof parsed['@context']['@vocab'] == 'string' &&
parsed['@context']['@vocab'].match(schemaDotOrgRegex));
if (!matches) {
return;
}
if (!parsed['@type'] && Array.isArray(parsed['@graph'])) {
parsed = parsed['@graph'].find((it) => {
return (it['@type'] || '').match(this.REGEXPS.jsonLdArticleTypes);
});
}
if (
!parsed ||
!parsed['@type'] ||
!parsed['@type'].match(this.REGEXPS.jsonLdArticleTypes)
) {
return;
}
metadata = {};
if (
typeof parsed.name === 'string' &&
typeof parsed.headline === 'string' &&
parsed.name !== parsed.headline
) {
// we have both name and headline element in the JSON-LD. They should both be the same but some websites like aktualne.cz
// put their own name into "name" and the article title to "headline" which confuses Readability. So we try to check if either
// "name" or "headline" closely matches the html title, and if so, use that one. If not, then we use "name" by default.
var title = this._getArticleTitle();
var nameMatches = this._textSimilarity(parsed.name, title) > 0.75;
var headlineMatches = this._textSimilarity(parsed.headline, title) > 0.75;
if (headlineMatches && !nameMatches) {
metadata.title = parsed.headline;
} else {
metadata.title = parsed.name;
}
} else if (typeof parsed.name === 'string') {
metadata.title = parsed.name.trim();
} else if (typeof parsed.headline === 'string') {
metadata.title = parsed.headline.trim();
}
if (parsed.author) {
if (typeof parsed.author.name === 'string') {
metadata.byline = parsed.author.name.trim();
} else if (
Array.isArray(parsed.author) &&
parsed.author[0] &&
typeof parsed.author[0].name === 'string'
) {
metadata.byline = parsed.author
.filter(function (author) {
return author && typeof author.name === 'string';
})
.map(function (author) {
return author.name.trim();
})
.join(', ');
}
}
if (typeof parsed.description === 'string') {
metadata.excerpt = parsed.description.trim();
}
if (parsed.publisher && typeof parsed.publisher.name === 'string') {
metadata.siteName = parsed.publisher.name.trim();
}
if (typeof parsed.datePublished === 'string') {
metadata.datePublished = parsed.datePublished.trim();
}
} catch (err) {
this.log(err.message);
}
}
});
return metadata ? metadata : {};
},
/**
* Attempts to get excerpt and byline metadata for the article.
*
* @param {Object} jsonld — object containing any metadata that
* could be extracted from JSON-LD object.
*
* @return Object with optional "excerpt" and "byline" properties
*/
_getArticleMetadata(jsonld) {
var metadata = {};
var values = {};
var metaElements = this._doc.getElementsByTagName('meta');
// property is a space-separated list of values
var propertyPattern =
/\s*(article|dc|dcterm|og|twitter)\s*:\s*(author|creator|description|published_time|title|site_name)\s*/gi;
// name is a single value
var namePattern =
/^\s*(?:(dc|dcterm|og|twitter|parsely|weibo:(article|webpage))\s*[-\.:]\s*)?(author|creator|pub-date|description|title|site_name)\s*$/i;
// Find description tags.
this._forEachNode(metaElements, function (element) {
var elementName = element.getAttribute('name');
var elementProperty = element.getAttribute('property');
var content = element.getAttribute('content');
if (!content) {
return;
}
var matches = null;
var name = null;
if (elementProperty) {
matches = elementProperty.match(propertyPattern);
if (matches) {
// Convert to lowercase, and remove any whitespace
// so we can match below.
name = matches[0].toLowerCase().replace(/\s/g, '');
// multiple authors
values[name] = content.trim();
}
}
if (!matches && elementName && namePattern.test(elementName)) {
name = elementName;
if (content) {
// Convert to lowercase, remove any whitespace, and convert dots
// to colons so we can match below.
name = name.toLowerCase().replace(/\s/g, '').replace(/\./g, ':');
values[name] = content.trim();
}
}
});
// get title
metadata.title =
jsonld.title ||
values['dc:title'] ||
values['dcterm:title'] ||
values['og:title'] ||
values['weibo:article:title'] ||
values['weibo:webpage:title'] ||
values.title ||
values['twitter:title'] ||
values['parsely-title'];
if (!metadata.title) {
metadata.title = this._getArticleTitle();
}
const articleAuthor =
typeof values['article:author'] === 'string' && !this._isUrl(values['article:author'])
? values['article:author']
: undefined;
// get author
metadata.byline =
jsonld.byline ||
values['dc:creator'] ||
values['dcterm:creator'] ||
values.author ||
values['parsely-author'] ||
articleAuthor;
// get description
metadata.excerpt =
jsonld.excerpt ||
values['dc:description'] ||
values['dcterm:description'] ||
values['og:description'] ||
values['weibo:article:description'] ||
values['weibo:webpage:description'] ||
values.description ||
values['twitter:description'];
// get site name
metadata.siteName = jsonld.siteName || values['og:site_name'];
// get article published time
metadata.publishedTime =
jsonld.datePublished ||
values['article:published_time'] ||
values['parsely-pub-date'] ||
null;
// in many sites the meta value is escaped with HTML entities,
// so here we need to unescape it
metadata.title = this._unescapeHtmlEntities(metadata.title);
metadata.byline = this._unescapeHtmlEntities(metadata.byline);
metadata.excerpt = this._unescapeHtmlEntities(metadata.excerpt);
metadata.siteName = this._unescapeHtmlEntities(metadata.siteName);
metadata.publishedTime = this._unescapeHtmlEntities(metadata.publishedTime);
return metadata;
},
/**
* Check if node is image, or if node contains exactly only one image
* whether as a direct child or as its descendants.
*
* @param Element
**/
_isSingleImage(node) {
while (node) {
if (node.tagName === 'IMG') {
return true;
}
if (node.children.length !== 1 || node.textContent.trim() !== '') {
return false;
}
node = node.children[0];
}
return false;
},
/**
* Find all <noscript> that are located after <img> nodes, and which contain only one
* <img> element. Replace the first image with the image from inside the <noscript> tag,
* and remove the <noscript> tag. This improves the quality of the images we use on
* some sites (e.g. Medium).
*
* @param Element
**/
_unwrapNoscriptImages(doc) {
// Find img without source or attributes that might contains image, and remove it.
// This is done to prevent a placeholder img is replaced by img from noscript in next step.
var imgs = Array.from(doc.getElementsByTagName('img'));
this._forEachNode(imgs, function (img) {
for (var i = 0; i < img.attributes.length; i++) {
var attr = img.attributes[i];
switch (attr.name) {
case 'src':
case 'srcset':
case 'data-src':
case 'data-srcset':
return;
}
if (/\.(jpg|jpeg|png|webp)/i.test(attr.value)) {
return;
}
}
img.remove();
});
// Next find noscript and try to extract its image
var noscripts = Array.from(doc.getElementsByTagName('noscript'));
this._forEachNode(noscripts, function (noscript) {
// Parse content of noscript and make sure it only contains image
if (!this._isSingleImage(noscript)) {
return;
}
var tmp = doc.createElement('div');
// We're running in the document context, and using unmodified
// document contents, so doing this should be safe.
// (Also we heavily discourage people from allowing script to
// run at all in this document...)
// eslint-disable-next-line no-unsanitized/property
tmp.innerHTML = noscript.innerHTML;
// If noscript has previous sibling and it only contains image,
// replace it with noscript content. However we also keep old
// attributes that might contains image.
var prevElement = noscript.previousElementSibling;
if (prevElement && this._isSingleImage(prevElement)) {
var prevImg = prevElement;
if (prevImg.tagName !== 'IMG') {
prevImg = prevElement.getElementsByTagName('img')[0];
}
var newImg = tmp.getElementsByTagName('img')[0];
for (var i = 0; i < prevImg.attributes.length; i++) {
var attr = prevImg.attributes[i];
if (attr.value === '') {
continue;
}
if (
attr.name === 'src' ||
attr.name === 'srcset' ||
/\.(jpg|jpeg|png|webp)/i.test(attr.value)
) {
if (newImg.getAttribute(attr.name) === attr.value) {
continue;
}
var attrName = attr.name;
if (newImg.hasAttribute(attrName)) {
attrName = 'data-old-' + attrName;
}
newImg.setAttribute(attrName, attr.value);
}
}
noscript.parentNode.replaceChild(tmp.firstElementChild, prevElement);
}
});
},
/**
* Removes script tags from the document.
*
* @param Element
**/
_removeScripts(doc) {
this._removeNodes(this._getAllNodesWithTag(doc, ['script', '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(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(node) {
return (
node.nodeType === this.ELEMENT_NODE &&
!node.textContent.trim().length &&
(!node.children.length ||
node.children.length ==
node.getElementsByTagName('br').length + node.getElementsByTagName('hr').length)
);
},
/**
* Determine whether element has any children block level elements.
*
* @param Element
*/
_hasChildBlockElement(element) {
return this._someNode(element.childNodes, function (node) {
return this.DIV_TO_P_ELEMS.has(node.tagName) || 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(node) {
return (
node.nodeType === this.TEXT_NODE ||
this.PHRASING_ELEMS.includes(node.tagName) ||
((node.tagName === 'A' || node.tagName === 'DEL' || node.tagName === 'INS') &&
this._everyNode(node.childNodes, this._isPhrasingContent))
);
},
_isWhitespace(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(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(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(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.includes(e.tagName)) {
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(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) {
var href = linkNode.getAttribute('href');
var coefficient = href && this.REGEXPS.hashUrl.test(href) ? 0.3 : 1;
linkLength += this._getInnerText(linkNode).length * coefficient;
});
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(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(e, tag) {
var isEmbed = ['object', 'embed', 'iframe'].includes(tag);
this._removeNodes(this._getAllNodesWithTag(e, [tag]), function (element) {
// Allow youtube and vimeo videos through as people usually want to see those.
if (isEmbed) {
// First, check the elements attributes to see if any of them contain youtube or vimeo
for (var i = 0; i < element.attributes.length; i++) {
if (this._allowedVideoRegex.test(element.attributes[i].value)) {
return false;
}
}
// For embed with <object> tag, check inner HTML as well.
if (element.tagName === 'object' && this._allowedVideoRegex.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(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(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, columns };
},
/**
* Look for 'data' (as opposed to 'layout') tables, for which we use
* similar checks as
* https://searchfox.org/mozilla-central/rev/f82d5c549f046cb64ce5602bfd894b7ae807c8f8/accessible/generic/TableAccessible.cpp#19
*/
_markDataTables(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) {
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.columns == 1 || sizeInfo.rows == 1) {
// single colum/row tables are commonly used for page layout purposes.
table._readabilityDataTable = false;
continue;
}
if (sizeInfo.rows >= 10 || sizeInfo.columns > 4) {
table._readabilityDataTable = true;
continue;
}
// Now just go by size entirely:
table._readabilityDataTable = sizeInfo.rows * sizeInfo.columns > 10;
}
},
/* convert images and figures that have properties like data-src into images that can be loaded without JS */
_fixLazyImages(root) {
this._forEachNode(
this._getAllNodesWithTag(root, ['img', 'picture', 'figure']),
function (elem) {
// In some sites (e.g. Kotaku), they put 1px square image as base64 data uri in the src attribute.
// So, here we check if the data uri is too short, just might as well remove it.
if (elem.src && this.REGEXPS.b64DataUrl.test(elem.src)) {
// Make sure it's not SVG, because SVG can have a meaningful image in under 133 bytes.
var parts = this.REGEXPS.b64DataUrl.exec(elem.src);
if (parts[1] === 'image/svg+xml') {
return;
}
// Make sure this element has other attributes which contains image.
// If it doesn't, then this src is important and shouldn't be removed.
var srcCouldBeRemoved = false;
for (var i = 0; i < elem.attributes.length; i++) {
var attr = elem.attributes[i];
if (attr.name === 'src') {
continue;
}
if (/\.(jpg|jpeg|png|webp)/i.test(attr.value)) {
srcCouldBeRemoved = true;
break;
}
}
// Here we assume if image is less than 100 bytes (or 133 after encoded to base64)
// it will be too small, therefore it might be placeholder image.
if (srcCouldBeRemoved) {
var b64starts = parts[0].length;
var b64length = elem.src.length - b64starts;
if (b64length < 133) {
elem.removeAttribute('src');
}
}
}
// also check for "null" to work around https://github.com/jsdom/jsdom/issues/2580
if (
(elem.src || (elem.srcset && elem.srcset != 'null')) &&
!elem.className.toLowerCase().includes('lazy')
) {
return;
}
for (var j = 0; j < elem.attributes.length; j++) {
attr = elem.attributes[j];
if (attr.name === 'src' || attr.name === 'srcset' || attr.name === 'alt') {
continue;
}
var copyTo = null;
if (/\.(jpg|jpeg|png|webp)\s+\d/.test(attr.value)) {
copyTo = 'srcset';
} else if (/^\s*\S+\.(jpg|jpeg|png|webp)\S*\s*$/.test(attr.value)) {
copyTo = 'src';
}
if (copyTo) {
//if this is an img or picture, set the attribute directly
if (elem.tagName === 'IMG' || elem.tagName === 'PICTURE') {
elem.setAttribute(copyTo, attr.value);
} else if (
elem.tagName === 'FIGURE' &&
!this._getAllNodesWithTag(elem, ['img', 'picture']).length
) {
//if the item is a <figure> that does not contain an image or picture, create one and place it inside the figure
//see the nytimes-3 testcase for an example
var img = this._doc.createElement('img');
img.setAttribute(copyTo, attr.value);
elem.appendChild(img);
}
}
}
},
);
},
_getTextDensity(e, tags) {
var textLength = this._getInnerText(e, true).length;
if (textLength === 0) {
return 0;
}
var childrenLength = 0;
var children = this._getAllNodesWithTag(e, tags);
this._forEachNode(
children,
(child) => (childrenLength += this._getInnerText(child, true).length),
);
return childrenLength / textLength;
},
/**
* 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(e, tag) {
if (!this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY)) {
return;
}
// 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(this._getAllNodesWithTag(e, [tag]), function (node) {
// First check if this node IS data table, in which case don't remove it.
var isDataTable = function (t) {
return t._readabilityDataTable;
};
var isList = tag === 'ul' || tag === 'ol';
if (!isList) {
var listLength = 0;
var listNodes = this._getAllNodesWithTag(node, ['ul', 'ol']);
this._forEachNode(listNodes, (list) => (listLength += this._getInnerText(list).length));
isList = listLength / this._getInnerText(node).length > 0.9;
}
if (tag === 'table' && isDataTable(node)) {
return false;
}
// Next check if we're inside a data table, in which case don't remove it as well.
if (this._hasAncestorTag(node, 'table', -1, isDataTable)) {
return false;
}
if (this._hasAncestorTag(node, 'code')) {
return false;
}
// keep element if it has a data tables
if ([...node.getElementsByTagName('table')].some((tbl) => tbl._readabilityDataTable)) {
return false;
}
var weight = this._getClassWeight(node);
this.log('Cleaning Conditionally', node);
var contentScore = 0;
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 headingDensity = this._getTextDensity(node, ['h1', 'h2', 'h3', 'h4', 'h5', 'h6']);
var embedCount = 0;
var embeds = this._getAllNodesWithTag(node, ['object', 'embed', 'iframe']);
for (var i = 0; i < embeds.length; i++) {
// If this embed has attribute that matches video regex, don't delete it.
for (var j = 0; j < embeds[i].attributes.length; j++) {
if (this._allowedVideoRegex.test(embeds[i].attributes[j].value)) {
return false;
}
}
// For embed with <object> tag, check inner HTML as well.
if (
embeds[i].tagName === 'object' &&
this._allowedVideoRegex.test(embeds[i].innerHTML)
) {
return false;
}
embedCount++;
}
var innerText = this._getInnerText(node);
// toss any node whose inner text contains nothing but suspicious words
if (this.REGEXPS.adWords.test(innerText) || this.REGEXPS.loadingWords.test(innerText)) {
return true;
}
var contentLength = innerText.length;
var linkDensity = this._getLinkDensity(node);
var textishTags = ['SPAN', 'LI', 'TD'].concat(Array.from(this.DIV_TO_P_ELEMS));
var textDensity = this._getTextDensity(node, textishTags);
var isFigureChild = this._hasAncestorTag(node, 'figure');
// apply shadiness checks, then check for exceptions
const shouldRemoveNode = () => {
const errs = [];
if (!isFigureChild && img > 1 && p / img < 0.5) {
errs.push(`Bad p to img ratio (img=${img}, p=${p})`);
}
if (!isList && li > p) {
errs.push(`Too many li's outside of a list. (li=${li} > p=${p})`);
}
if (input > Math.floor(p / 3)) {
errs.push(`Too many inputs per p. (input=${input}, p=${p})`);
}
if (
!isList &&
!isFigureChild &&
headingDensity < 0.9 &&
contentLength < 25 &&
(img === 0 || img > 2) &&
linkDensity > 0
) {
errs.push(
`Suspiciously short. (headingDensity=${headingDensity}, img=${img}, linkDensity=${linkDensity})`,
);
}
if (!isList && weight < 25 && linkDensity > 0.2 + this._linkDensityModifier) {
errs.push(`Low weight and a little linky. (linkDensity=${linkDensity})`);
}
if (weight >= 25 && linkDensity > 0.5 + this._linkDensityModifier) {
errs.push(`High weight and mostly links. (linkDensity=${linkDensity})`);
}
if ((embedCount === 1 && contentLength < 75) || embedCount > 1) {
errs.push(
`Suspicious embed. (embedCount=${embedCount}, contentLength=${contentLength})`,
);
}
if (img === 0 && textDensity === 0) {
errs.push(`No useful content. (img=${img}, textDensity=${textDensity})`);
}
if (errs.length) {
this.log('Checks failed', errs);
return true;
}
return false;
};
var haveToRemove = shouldRemoveNode();
// Allow simple lists of images to remain in pages
if (isList && haveToRemove) {
for (var x = 0; x < node.children.length; x++) {
let child = node.children[x];
// Don't filter in lists with li's that contain more than one child
if (child.children.length > 1) {
return haveToRemove;
}
}
let li_count = node.getElementsByTagName('li').length;
// Only allow the list to remain if every li contains an image
if (img == li_count) {
return false;
}
}
return haveToRemove;
}
return false;
});
},
/**
* Clean out elements that match the specified conditions
*
* @param Element
* @param Function determines whether a node should be removed
* @return void
**/
_cleanMatchedNodes(e, filter) {
var endOfSearchMarkerNode = this._getNextNode(e, true);
var next = this._getNextNode(e);
while (next && next != endOfSearchMarkerNode) {
if (filter.call(this, next, next.className + ' ' + next.id)) {
next = this._removeAndGetNext(next);
} else {
next = this._getNextNode(next);
}
}
},
/**
* Clean out spurious headers from an Element.
*
* @param Element
* @return void
**/
_cleanHeaders(e) {
let headingNodes = this._getAllNodesWithTag(e, ['h1', 'h2']);
this._removeNodes(headingNodes, function (node) {
let shouldRemove = this._getClassWeight(node) < 0;
if (shouldRemove) {
this.log('Removing header with low class weight:', node);
}
return shouldRemove;
});
},
/**
* Check if this node is an H1 or H2 element whose content is mostly
* the same as the article title.
*
* @param Element the node to check.
* @return boolean indicating whether this is a title-like header.
*/
_headerDuplicatesTitle(node) {
if (node.tagName != 'H1' && node.tagName != 'H2') {
return false;
}
var heading = this._getInnerText(node, false);
this.log('Evaluating similarity of header:', heading, this._articleTitle);
return this._textSimilarity(this._articleTitle, heading) > 0.75;
},
_flagIsActive(flag) {
return (this._flags & flag) > 0;
},
_removeFlag(flag) {
this._flags = this._flags & ~flag;
},
_isProbablyVisible(node) {
// Have to null-check node.style and node.className.includes to deal with SVG and MathML nodes.
return (
(!node.style || node.style.display != 'none') &&
(!node.style || node.style.visibility != 'hidden') &&
!node.hasAttribute('hidden') &&
//check for "fallback-image" so that wikimedia math images are displayed
(!node.hasAttribute('aria-hidden') ||
node.getAttribute('aria-hidden') != 'true' ||
(node.className && node.className.includes && node.className.includes('fallback-image')))
);
},
/**
* 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() {
// 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');
}
}
// Unwrap image from noscript
this._unwrapNoscriptImages(this._doc);
// Extract JSON-LD metadata before removing scripts
var jsonLd = this._disableJSONLD ? {} : this._getJSONLD(this._doc);
// Remove script tags from the document.
this._removeScripts(this._doc);
this._prepDocument();
var metadata = this._getArticleMetadata(jsonLd);
this._metadata = metadata;
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) {
metadata.excerpt = paragraphs[0].textContent.trim();
}
}
var textContent = articleContent.textContent;
return {
title: this._articleTitle,
byline: metadata.byline || this._articleByline,
dir: this._articleDir,
lang: this._articleLang,
content: this._serializer(articleContent),
textContent,
length: textContent.length,
excerpt: metadata.excerpt,
siteName: metadata.siteName || this._articleSiteName,
publishedTime: metadata.publishedTime,
};
},
};
if (typeof module === 'object') {
/* global module */
module.exports = Readability;
}
/**
* Web Fetcher Helper Content Script
* Handles fetching HTML content, text content, and interactive elements from the current page
* Supports Readability for better content extraction
*/
// Configuration
const config = {
// Elements that should be ignored when extracting content (used for iframe content and fallback extraction)
ignoreElements: [
'nav',
'header:not(article header)',
'footer:not(article footer)',
'aside',
'script',
'style',
'noscript',
'iframe[src*="ads"]',
'.cookie-notice',
'.ad',
'.ads',
'.advertisement',
'.banner',
'.popup',
'.modal',
'.overlay',
'.social-share',
'.social-links',
'.related-articles',
'.comments',
],
minTextLength: 20,
maxTotalLength: 100000,
minParagraphLength: 2,
};
// Listen for messages from the extension
chrome.runtime.onMessage.addListener((request, _sender, sendResponse) => {
const pingActions = ['search_tabs_content_ping', 'chrome_web_fetcher_ping'];
// Respond to ping message
if (pingActions.includes(request.action)) {
sendResponse({ status: 'pong' });
return false; // Synchronous response
}
// Get HTML content
else if (request.action === 'getHtmlContent') {
try {
let rawHtml;
// If selector is specified, only get content from the matching element
if (request.selector) {
const element = document.querySelector(request.selector);
if (element) {
rawHtml = element.outerHTML;
} else {
throw new Error(`No element found matching selector: ${request.selector}`);
}
} else {
// Otherwise get the entire page content
rawHtml = document.documentElement.outerHTML;
}
const cleanedHtml = cleanHtmlContent(rawHtml);
sendResponse({
success: true,
htmlContent: cleanedHtml,
selector: request.selector,
});
} catch (error) {
sendResponse({
success: false,
error: `Failed to get HTML content: ${error.message}`,
});
}
}
// Get text content
else if (request.action === 'getTextContent') {
try {
// If selector is specified, only get content from the matching element
if (request.selector) {
const element = document.querySelector(request.selector);
if (element) {
// Directly get the text content of the element
const textContent = element.innerText;
sendResponse({
success: true,
textContent: textContent,
selector: request.selector,
});
} else {
throw new Error(`No element found matching selector: ${request.selector}`);
}
} else {
// Otherwise use Readability to extract the main content
const documentClone = document.cloneNode(true);
const reader = new Readability(documentClone);
const article = reader.parse();
if (article && article.textContent) {
// Get metadata
const metadata = extractPageMetadata();
// Get iframe content if available
const iframeContent = extractIframeContent();
// Combine content
let fullContent = article.textContent;
if (iframeContent && iframeContent.trim().length > config.minTextLength) {
fullContent += '\n\n--- Embedded Content ---\n\n' + iframeContent;
}
// Clean content
fullContent = cleanContent(fullContent);
sendResponse({
success: true,
textContent: fullContent,
article: {
title: article.title,
byline: article.byline,
siteName: article.siteName,
excerpt: article.excerpt,
lang: article.lang,
content: article.content, // HTML content
},
metadata: metadata,
});
} else {
// Fallback to basic extraction
const textContent = document.body.innerText;
sendResponse({
success: true,
textContent: textContent,
fallback: true,
});
}
}
} catch (error) {
console.error('Error extracting text content:', error);
sendResponse({
success: false,
error: `Failed to extract text content: ${error.message}`,
});
}
return true; // Async response
}
// Interactive elements feature has been removed
return true; // Async response
});
/**
* Extract metadata from the page
* @returns {Object} - Page metadata
*/
function extractPageMetadata() {
const metadata = {
title: document.title,
description: '',
author: '',
keywords: '',
published: '',
siteName: '',
};
// Extract description
const descriptionElement = document.querySelector(
'meta[name="description"], meta[property="og:description"]',
);
if (descriptionElement) {
metadata.description = descriptionElement.getAttribute('content') || '';
}
// Extract author
const authorElement = document.querySelector(
'meta[name="author"], meta[property="article:author"]',
);
if (authorElement) {
metadata.author = authorElement.getAttribute('content') || '';
}
// Extract keywords
const keywordsElement = document.querySelector('meta[name="keywords"]');
if (keywordsElement) {
metadata.keywords = keywordsElement.getAttribute('content') || '';
}
// Extract published date
const publishedElement = document.querySelector(
'meta[property="article:published_time"], time[datetime]',
);
if (publishedElement) {
metadata.published =
publishedElement.getAttribute('content') || publishedElement.getAttribute('datetime') || '';
}
// Extract site name
const siteNameElement = document.querySelector('meta[property="og:site_name"]');
if (siteNameElement) {
metadata.siteName = siteNameElement.getAttribute('content') || '';
}
return metadata;
}
/**
* Extract content from iframes
* @returns {string} - Combined iframe content
*/
function extractIframeContent() {
let allIframeText = '';
const iframes = document.querySelectorAll('iframe');
for (const iframe of iframes) {
try {
if (isSameOrigin(iframe) && isElementVisible(iframe)) {
const doc = iframe.contentDocument || iframe.contentWindow?.document;
if (doc) {
const iframeText = doc.body.innerText;
if (iframeText && iframeText.trim().length >= config.minTextLength) {
allIframeText += iframeText.trim() + '\n\n';
}
}
}
} catch (error) {
console.warn(
`Cannot access iframe content (possible cross-origin restriction): ${error.message}`,
);
}
}
return allIframeText.trim();
}
/**
* Check if iframe is same origin
* @param {HTMLIFrameElement} iframe - The iframe to check
* @returns {boolean} - Whether the iframe is same origin
*/
function isSameOrigin(iframe) {
try {
return Boolean(iframe.contentDocument || iframe.contentWindow?.document);
} catch (e) {
return false;
}
}
/**
* Clean content text
* @param {string} text - The text to clean
* @returns {string} - Cleaned text
*/
function cleanContent(text) {
return text
.replace(/\s+/g, ' ')
.replace(/\n\s*\n/g, '\n\n')
.trim()
.substring(0, config.maxTotalLength);
}
/**
* Clean HTML content by removing style tags and their content
* @param {string} html - The HTML content to clean
* @returns {string} - Cleaned HTML content
*/
function cleanHtmlContent(html) {
// Create a new document parser
const parser = new DOMParser();
const doc = parser.parseFromString(html, 'text/html');
// Remove all style tags
const styleElements = doc.querySelectorAll('style');
styleElements.forEach((element) => {
if (element.parentNode) {
element.parentNode.removeChild(element);
}
});
// Remove all inline style attributes
const allElementsWithStyle = doc.querySelectorAll('*');
allElementsWithStyle.forEach((element) => {
element.removeAttribute('style');
});
// Remove all link tags
const linkElements = doc.querySelectorAll('link');
linkElements.forEach((element) => {
if (element.parentNode) {
element.parentNode.removeChild(element);
}
});
// Remove all script tags
const scriptElements = doc.querySelectorAll('script');
scriptElements.forEach((element) => {
if (element.parentNode) {
element.parentNode.removeChild(element);
}
});
// Replace all SVG elements with placeholders
const svgElements = doc.querySelectorAll('svg');
svgElements.forEach((element) => {
if (element.parentNode) {
// Create a placeholder element
const placeholder = doc.createElement('span');
placeholder.textContent = '[SVG Icon]';
placeholder.setAttribute('data-placeholder', 'svg-icon');
// Replace SVG element
element.parentNode.replaceChild(placeholder, element);
}
});
// Replace all SVG images and objects
const svgImages = doc.querySelectorAll(
'img[src$=".svg"], object[data$=".svg"], embed[src$=".svg"]',
);
svgImages.forEach((element) => {
if (element.parentNode) {
// Create a placeholder element
const placeholder = doc.createElement('span');
placeholder.textContent = '[SVG Image]';
placeholder.setAttribute('data-placeholder', 'svg-image');
if (element.alt) {
placeholder.textContent = `[SVG Image: ${element.alt}]`;
}
// Replace SVG image element
element.parentNode.replaceChild(placeholder, element);
}
});
// Remove elements with only data-* attributes, no children, and no class or style
const allElements = Array.from(doc.querySelectorAll('*'));
allElements.forEach((element) => {
// Check if element has only data-* attributes
let hasOnlyDataAttributes = true;
let hasDataAttribute = false;
// Check all attributes
for (let i = 0; i < element.attributes.length; i++) {
const attr = element.attributes[i];
if (attr.name.startsWith('data-')) {
hasDataAttribute = true;
} else if (attr.name !== 'id') {
// Allow id attribute
hasOnlyDataAttributes = false;
break;
}
}
// If element has only data-* attributes, no children, and no text content
if (
hasOnlyDataAttributes &&
hasDataAttribute &&
element.children.length === 0 &&
element.textContent.trim() === ''
) {
// Remove the element
if (element.parentNode) {
element.parentNode.removeChild(element);
}
}
});
// Remove all HTML comments
const removeComments = (node) => {
const childNodes = node.childNodes;
for (let i = childNodes.length - 1; i >= 0; i--) {
const child = childNodes[i];
if (child.nodeType === 8) {
// Comment node
node.removeChild(child);
} else if (child.nodeType === 1) {
// Element node
removeComments(child);
}
}
};
removeComments(doc);
// Return cleaned HTML
return new XMLSerializer().serializeToString(doc);
}
// Interactive elements feature has been removed
// Selector generation feature has been removed
}