/* eslint-env es6:false */ /* * Copyright (c) 2010 Arc90 Inc * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * This code is heavily based on Arc90's readability.js (1.7.1) script * available at: http://code.google.com/p/arc90labs-readability */ var REGEXPS = { // NOTE: These two regular expressions are duplicated in // Readability.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, }; function isNodeVisible(node) { // Have to null-check node.style and node.className.indexOf to deal with SVG and MathML nodes. return (!node.style || node.style.display != "none") && !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.indexOf && node.className.indexOf("fallback-image") !== -1)); } /** * Decides whether or not the document is reader-able without parsing the whole thing. * * @return boolean Whether or not we suspect Readability.parse() will suceeed at returning an article object. */ function isProbablyReaderable(doc, isVisible) { if (!isVisible) { isVisible = isNodeVisible; } var nodes = doc.querySelectorAll("p, pre"); // Get
nodes which have
node(s) and append them into the `nodes` variable. // Some articles' DOM structures might look like //
// Sentences
//
// Sentences
//
var brNodes = doc.querySelectorAll("div > br"); if (brNodes.length) { var set = new Set(nodes); [].forEach.call(brNodes, function(node) { set.add(node.parentNode); }); nodes = Array.from(set); } var score = 0; // This is a little cheeky, we use the accumulator 'score' to decide what to return from // this callback: return [].some.call(nodes, function(node) { if (!isVisible(node)) return false; var matchString = node.className + " " + node.id; if (REGEXPS.unlikelyCandidates.test(matchString) && !REGEXPS.okMaybeItsACandidate.test(matchString)) { return false; } if (node.matches("li p")) { return false; } var textContentLength = node.textContent.trim().length; if (textContentLength < 140) { return false; } score += Math.sqrt(textContentLength - 140); if (score > 20) { return true; } return false; }); } if (typeof module === "object") { module.exports = isProbablyReaderable; }