非公開 記事本文自動読み上げツール

  • /*
     * @title 記事本文自動読み上げツール
     * @description <p>タグの多いDIV要素を探して https://developer.mozilla.org/en-US/docs/Web/API/Web_Speech_API で読み上げます
     * @include http://*
     * @license MIT License
     * @require https://raw.githubusercontent.com/mozilla/readability/master/Readability.js
     * @javascript_url
     * @private
     */
    
    /*eslint-env es6:false*/
    /*
     * Copyright (c) 2010 Arc90 Inc
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *     http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    
    /*
     * This code is heavily based on Arc90's readability.js (1.7.1) script
     * available at: http://code.google.com/p/arc90labs-readability
     */
    
    /**
     * Public constructor.
     * @param {HTMLDocument} doc     The document to parse.
     * @param {Object}       options The options object.
     */
    function Readability(doc, options) {
      // In some older versions, people passed a URI as the first argument. Cope:
      if (options && options.documentElement) {
        doc = options;
        options = arguments[2];
      } else if (!doc || !doc.documentElement) {
        throw new Error("First argument to Readability constructor should be a document object.");
      }
      options = options || {};
    
      this._doc = doc;
      this._docJSDOMParser = this._doc.firstChild.__JSDOMParser__;
      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 || []);
      this._keepClasses = !!options.keepClasses;
      this._serializer = options.serializer || function(el) {
        return el.innerHTML;
      };
      this._disableJSONLD = !!options.disableJSONLD;
    
      // 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 dump !== "undefined") {
            var msg = Array.prototype.map.call(arguments, function(x) {
              return (x && x.nodeName) ? logNode(x) : x;
            }).join(" ");
            dump("Reader: (Readability) " + msg + "\n");
          } else 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)");
            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.
        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|foot|footer|footnote|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget/i,
        extraneous: /print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single|utility/i,
        byline: /byline|author|dateline|writtenby|p-author/i,
        replaceFonts: /<(\/?)font[^>]*>/gi,
        normalize: /\s{2,}/g,
        videos: /\/\/(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)/i,
        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*(?:,|$))/g,
        b64DataUrl: /^data:\s*([^\s;,]+)\s*;\s*base64\s*,/i,
        // See: https://schema.org/Article
        jsonLdArticleTypes: /^Article|AdvertiserContentArticle|NewsArticle|AnalysisNewsArticle|AskPublicNewsArticle|BackgroundNewsArticle|OpinionNewsArticle|ReportageNewsArticle|ReviewNewsArticle|Report|SatiricalArticle|ScholarlyArticle|MedicalScholarlyArticle|SocialMediaPosting|BlogPosting|LiveBlogPosting|DiscussionForumPosting|TechArticle|APIReference$/
      },
    
      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"],
    
      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: function(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: function(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: function(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: function(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: function(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: 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) {
            // 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: function(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.setAttribute(node.attributes[i].name, node.attributes[i].value);
              }
              node.parentNode.replaceChild(child, node);
              node = child;
              continue;
            }
          }
    
          node = this._getNextNode(node);
        }
      },
    
      /**
       * Get the article title as an H1.
       *
       * @return string
       **/
      _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(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: function (node) {
        var next = node;
        while (next
            && (next.nodeType != this.ELEMENT_NODE)
            && this.REGEXPS.whitespace.test(next.textContent)) {
          next = next.nextSibling;
        }
        return next;
      },
    
      /**
       * Replaces 2 or more successive <br> elements with a single <p>.
       * Whitespace between <br> elements are ignored. For example:
       *   <div>foo<br>bar<br> <br><br>abc</div>
       * will become:
       *   <div>foo<br>bar<p>abc</p></div>
       */
      _replaceBrs: function (elem) {
        this._forEachNode(this._getAllNodesWithTag(elem, ["br"]), function(br) {
          var next = br.nextSibling;
    
          // Whether 2 or more <br> elements have been found and replaced with a
          // <p> block.
          var replaced = false;
    
          // If we find a <br> chain, remove the <br>s until we hit another 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.parentNode.removeChild(next);
            next = brSibling;
          }
    
          // If we removed a <br> chain, replace the remaining <br> with a <p>. Add
          // all sibling nodes as children of the <p> until we hit another <br>
          // chain.
          if (replaced) {
            var p = this._doc.createElement("p");
            br.parentNode.replaceChild(p, br);
    
            next = p.nextSibling;
            while (next) {
              // If we've hit another <br><br>, we're done adding children to this <p>.
              if (next.tagName == "BR") {
                var nextElem = this._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.removeChild(p.lastChild);
            }
    
            if (p.parentNode.tagName === "P")
              this._setNodeTag(p.parentNode, "DIV");
          }
        });
      },
    
      _setNodeTag: function (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++) {
          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 <p> tags, etc.
       *
       * @param Element
       * @return void
       **/
      _prepArticle: function(articleContent) {
        this._cleanStyles(articleContent);
    
        // Check for data tables before we continue, to avoid removing items in
        // those tables, which will often be isolated even though they're
        // visually linked to other content-ful elements (text, images, etc.).
        this._markDataTables(articleContent);
    
        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) {
          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._nextNode(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;
      },
    
      // 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: function(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;
      },
    
      _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;
        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;
            }
    
            // 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;
            }
    
            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.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, 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(",").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.indexOf(sibling.nodeName) === -1) {
                // We have a node that isn't a common block level element, like a form or td tag.
                // Turn it into a div so it doesn't get filtered out later by accident.
                this.log("Altering sibling:", sibling, "to div.");
    
                sibling = this._setNodeTag(sibling, "DIV");
              }
    
              articleContent.appendChild(sibling);
              // 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;
            page.innerHTML = pageCacheHtml;
    
            if (this._flagIsActive(this.FLAG_STRIP_UNLIKELYS)) {
              this._removeFlag(this.FLAG_STRIP_UNLIKELYS);
              this._attempts.push({articleContent: articleContent, textLength: textLength});
            } else if (this._flagIsActive(this.FLAG_WEIGHT_CLASSES)) {
              this._removeFlag(this.FLAG_WEIGHT_CLASSES);
              this._attempts.push({articleContent: articleContent, textLength: textLength});
            } else if (this._flagIsActive(this.FLAG_CLEAN_CONDITIONALLY)) {
              this._removeFlag(this.FLAG_CLEAN_CONDITIONALLY);
              this._attempts.push({articleContent: articleContent, textLength: textLength});
            } else {
              this._attempts.push({articleContent: articleContent, textLength: textLength});
              // No luck after removing flags, just return the longest text we found during the different loops
              this._attempts.sort(function (a, b) {
                return 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;
          }
        }
      },
    
      /**
       * Check whether the input string could be a byline.
       * This verifies that the input is a string, and that the length
       * is less than 100 chars.
       *
       * @param possibleByline {string} - a string to check whether its a byline.
       * @return Boolean - whether the input string is a byline.
       */
      _isValidByline: function(byline) {
        if (typeof byline == "string" || byline instanceof String) {
          byline = byline.trim();
          return (byline.length > 0) && (byline.length < 100);
        }
        return false;
      },
    
      /**
       * 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: function(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-z]{1,4})|([0-9]{1,4}));/gi, function(_, hex, numStr) {
          var num = parseInt(hex || numStr, hex ? 16 : 10);
          return String.fromCharCode(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: function (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*$/g, "");
              var parsed = JSON.parse(content);
              if (
                !parsed["@context"] ||
                !parsed["@context"].match(/^https?\:\/\/schema\.org$/)
              ) {
                return;
              }
    
              if (!parsed["@type"] && Array.isArray(parsed["@graph"])) {
                parsed = parsed["@graph"].find(function(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();
              }
              return;
            } 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: function(jsonld) {
        var metadata = {};
        var values = {};
        var metaElements = this._doc.getElementsByTagName("meta");
    
        // property is a space-separated list of values
        var propertyPattern = /\s*(dc|dcterm|og|twitter)\s*:\s*(author|creator|description|title|site_name)\s*/gi;
    
        // name is a single value
        var namePattern = /^\s*(?:(dc|dcterm|og|twitter|weibo:(article|webpage))\s*[\.:]\s*)?(author|creator|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"];
    
        if (!metadata.title) {
          metadata.title = this._getArticleTitle();
        }
    
        // get author
        metadata.byline = jsonld.byline ||
                          values["dc:creator"] ||
                          values["dcterm:creator"] ||
                          values["author"];
    
        // 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"];
    
        // 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);
    
        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: function(node) {
        if (node.tagName === "IMG") {
          return true;
        }
    
        if (node.children.length !== 1 || node.textContent.trim() !== "") {
          return false;
        }
    
        return this._isSingleImage(node.children[0]);
      },
    
      /**
       * 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: function(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.parentNode.removeChild(img);
        });
    
        // 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
          var tmp = doc.createElement("div");
          tmp.innerHTML = noscript.innerHTML;
          if (!this._isSingleImage(tmp)) {
            return;
          }
    
          // 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: function(doc) {
        this._removeNodes(this._getAllNodesWithTag(doc, ["script"]), function(scriptNode) {
          scriptNode.nodeValue = "";
          scriptNode.removeAttribute("src");
          return true;
        });
        this._removeNodes(this._getAllNodesWithTag(doc, ["noscript"]));
      },
    
      /**
       * Check if this node has only whitespace and a single element with given tag
       * Returns false if the DIV node contains non-empty text nodes
       * or if it contains no element with given tag or more than 1 element.
       *
       * @param Element
       * @param string tag of child element
      **/
      _hasSingleTagInsideElement: function(element, tag) {
        // There should be exactly 1 element child with given tag
        if (element.children.length != 1 || element.children[0].tagName !== tag) {
          return false;
        }
    
        // And there should be no text nodes with real content
        return !this._someNode(element.childNodes, function(node) {
          return node.nodeType === this.TEXT_NODE &&
                 this.REGEXPS.hasContent.test(node.textContent);
        });
      },
    
      _isElementWithoutContent: function(node) {
        return node.nodeType === this.ELEMENT_NODE &&
          node.textContent.trim().length == 0 &&
          (node.children.length == 0 ||
           node.children.length == node.getElementsByTagName("br").length + node.getElementsByTagName("hr").length);
      },
    
      /**
       * Determine whether element has any children block level elements.
       *
       * @param Element
       */
      _hasChildBlockElement: function (element) {
        return this._someNode(element.childNodes, function(node) {
          return this.DIV_TO_P_ELEMS.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: function(node) {
        return node.nodeType === this.TEXT_NODE || this.PHRASING_ELEMS.indexOf(node.tagName) !== -1 ||
          ((node.tagName === "A" || node.tagName === "DEL" || node.tagName === "INS") &&
            this._everyNode(node.childNodes, this._isPhrasingContent));
      },
    
      _isWhitespace: function(node) {
        return (node.nodeType === this.TEXT_NODE && node.textContent.trim().length === 0) ||
               (node.nodeType === this.ELEMENT_NODE && node.tagName === "BR");
      },
    
      /**
       * Get the inner text of a node - cross browser compatibly.
       * This also strips out any excess whitespace to be found.
       *
       * @param Element
       * @param Boolean normalizeSpaces (default: true)
       * @return string
      **/
      _getInnerText: function(e, normalizeSpaces) {
        normalizeSpaces = (typeof normalizeSpaces === "undefined") ? true : normalizeSpaces;
        var textContent = e.textContent.trim();
    
        if (normalizeSpaces) {
          return textContent.replace(this.REGEXPS.normalize, " ");
        }
        return textContent;
      },
    
      /**
       * Get the number of times a string s appears in the node e.
       *
       * @param Element
       * @param string - what to split on. Default is ","
       * @return number (integer)
      **/
      _getCharCount: function(e, s) {
        s = s || ",";
        return this._getInnerText(e).split(s).length - 1;
      },
    
      /**
       * Remove the style attribute on every e and under.
       * TODO: Test if getElementsByTagName(*) is faster.
       *
       * @param Element
       * @return void
      **/
      _cleanStyles: function(e) {
        if (!e || e.tagName.toLowerCase() === "svg")
          return;
    
        // Remove `style` and deprecated presentational attributes
        for (var i = 0; i < this.PRESENTATIONAL_ATTRIBUTES.length; i++) {
          e.removeAttribute(this.PRESENTATIONAL_ATTRIBUTES[i]);
        }
    
        if (this.DEPRECATED_SIZE_ATTRIBUTE_ELEMS.indexOf(e.tagName) !== -1) {
          e.removeAttribute("width");
          e.removeAttribute("height");
        }
    
        var cur = e.firstElementChild;
        while (cur !== null) {
          this._cleanStyles(cur);
          cur = cur.nextElementSibling;
        }
      },
    
      /**
       * Get the density of links as a percentage of the content
       * This is the amount of text that is inside a link divided by the total text in the node.
       *
       * @param Element
       * @return number (float)
      **/
      _getLinkDensity: function(element) {
        var textLength = this._getInnerText(element).length;
        if (textLength === 0)
          return 0;
    
        var linkLength = 0;
    
        // XXX implement _reduceNodeList?
        this._forEachNode(element.getElementsByTagName("a"), function(linkNode) {
          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: function(e) {
        if (!this._flagIsActive(this.FLAG_WEIGHT_CLASSES))
          return 0;
    
        var weight = 0;
    
        // Look for a special classname
        if (typeof(e.className) === "string" && e.className !== "") {
          if (this.REGEXPS.negative.test(e.className))
            weight -= 25;
    
          if (this.REGEXPS.positive.test(e.className))
            weight += 25;
        }
    
        // Look for a special ID
        if (typeof(e.id) === "string" && e.id !== "") {
          if (this.REGEXPS.negative.test(e.id))
            weight -= 25;
    
          if (this.REGEXPS.positive.test(e.id))
            weight += 25;
        }
    
        return weight;
      },
    
      /**
       * Clean a node of all elements of type "tag".
       * (Unless it's a youtube/vimeo video. People love movies.)
       *
       * @param Element
       * @param string tag to clean
       * @return void
       **/
      _clean: function(e, tag) {
        var isEmbed = ["object", "embed", "iframe"].indexOf(tag) !== -1;
    
        this._removeNodes(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.REGEXPS.videos.test(element.attributes[i].value)) {
                return false;
              }
            }
    
            // For embed with <object> tag, check inner HTML as well.
            if (element.tagName === "object" && this.REGEXPS.videos.test(element.innerHTML)) {
              return false;
            }
          }
    
          return true;
        });
      },
    
      /**
       * Check if a given node has one of its ancestor tag name matching the
       * provided one.
       * @param  HTMLElement node
       * @param  String      tagName
       * @param  Number      maxDepth
       * @param  Function    filterFn a filter to invoke to determine whether this node 'counts'
       * @return Boolean
       */
      _hasAncestorTag: function(node, tagName, maxDepth, filterFn) {
        maxDepth = maxDepth || 3;
        tagName = tagName.toUpperCase();
        var depth = 0;
        while (node.parentNode) {
          if (maxDepth > 0 && depth > maxDepth)
            return false;
          if (node.parentNode.tagName === tagName && (!filterFn || filterFn(node.parentNode)))
            return true;
          node = node.parentNode;
          depth++;
        }
        return false;
      },
    
      /**
       * Return an object indicating how many rows and columns this table has.
       */
      _getRowAndColumnCount: function(table) {
        var rows = 0;
        var columns = 0;
        var trs = table.getElementsByTagName("tr");
        for (var i = 0; i < trs.length; i++) {
          var rowspan = trs[i].getAttribute("rowspan") || 0;
          if (rowspan) {
            rowspan = parseInt(rowspan, 10);
          }
          rows += (rowspan || 1);
    
          // Now look for column-related info
          var columnsInThisRow = 0;
          var cells = trs[i].getElementsByTagName("td");
          for (var j = 0; j < cells.length; j++) {
            var colspan = cells[j].getAttribute("colspan") || 0;
            if (colspan) {
              colspan = parseInt(colspan, 10);
            }
            columnsInThisRow += (colspan || 1);
          }
          columns = Math.max(columns, columnsInThisRow);
        }
        return {rows: rows, columns: columns};
      },
    
      /**
       * Look for 'data' (as opposed to 'layout') tables, for which we use
       * similar checks as
       * https://searchfox.org/mozilla-central/rev/f82d5c549f046cb64ce5602bfd894b7ae807c8f8/accessible/generic/TableAccessible.cpp#19
       */
      _markDataTables: function(root) {
        var tables = root.getElementsByTagName("table");
        for (var i = 0; i < tables.length; i++) {
          var table = tables[i];
          var role = table.getAttribute("role");
          if (role == "presentation") {
            table._readabilityDataTable = false;
            continue;
          }
          var datatable = table.getAttribute("datatable");
          if (datatable == "0") {
            table._readabilityDataTable = false;
            continue;
          }
          var summary = table.getAttribute("summary");
          if (summary) {
            table._readabilityDataTable = true;
            continue;
          }
    
          var caption = table.getElementsByTagName("caption")[0];
          if (caption && caption.childNodes.length > 0) {
            table._readabilityDataTable = true;
            continue;
          }
    
          // If the table has a descendant with any of these tags, consider a data table:
          var dataTableDescendants = ["col", "colgroup", "tfoot", "thead", "th"];
          var descendantExists = function(tag) {
            return !!table.getElementsByTagName(tag)[0];
          };
          if (dataTableDescendants.some(descendantExists)) {
            this.log("Data table because found data-y descendant");
            table._readabilityDataTable = true;
            continue;
          }
    
          // Nested tables indicate a layout table:
          if (table.getElementsByTagName("table")[0]) {
            table._readabilityDataTable = false;
            continue;
          }
    
          var sizeInfo = this._getRowAndColumnCount(table);
          if (sizeInfo.rows >= 10 || sizeInfo.columns > 4) {
            table._readabilityDataTable = true;
            continue;
          }
          // Now just go by size entirely:
          table._readabilityDataTable = sizeInfo.rows * sizeInfo.columns > 10;
        }
      },
    
      /* convert images and figures that have properties like data-src into images that can be loaded without JS */
      _fixLazyImages: function (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 133B after encoded to base64)
            // it will be too small, therefore it might be placeholder image.
            if (srcCouldBeRemoved) {
              var b64starts = elem.src.search(/base64\s*/i) + 7;
              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().indexOf("lazy") === -1) {
            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: function(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: function(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;
          }
    
          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.REGEXPS.videos.test(embeds[i].attributes[j].value)) {
                  return false;
                }
              }
    
              // For embed with <object> tag, check inner HTML as well.
              if (embeds[i].tagName === "object" && this.REGEXPS.videos.test(embeds[i].innerHTML)) {
                return false;
              }
    
              embedCount++;
            }
    
            var linkDensity = this._getLinkDensity(node);
            var contentLength = this._getInnerText(node).length;
    
            var haveToRemove =
              (img > 1 && p / img < 0.5 && !this._hasAncestorTag(node, "figure")) ||
              (!isList && li > p) ||
              (input > Math.floor(p/3)) ||
              (!isList && headingDensity < 0.9 && contentLength < 25 && (img === 0 || img > 2) && !this._hasAncestorTag(node, "figure")) ||
              (!isList && weight < 25 && linkDensity > 0.2) ||
              (weight >= 25 && linkDensity > 0.5) ||
              ((embedCount === 1 && contentLength < 75) || embedCount > 1);
            return haveToRemove;
          }
          return false;
        });
      },
    
      /**
       * Clean out elements that match the specified conditions
       *
       * @param Element
       * @param Function determines whether a node should be removed
       * @return void
       **/
      _cleanMatchedNodes: function(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: function(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: function(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: function(flag) {
        return (this._flags & flag) > 0;
      },
    
      _removeFlag: function(flag) {
        this._flags = this._flags & ~flag;
      },
    
      _isProbablyVisible: function(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));
      },
    
      /**
       * Runs readability.
       *
       * Workflow:
       *  1. Prep the document by removing script tags, css, etc.
       *  2. Build readability's DOM tree.
       *  3. Grab the article content from the current dom tree.
       *  4. Replace the current DOM tree with the new one.
       *  5. Read peacefully.
       *
       * @return void
       **/
      parse: function () {
        // Avoid parsing too large documents, as per configuration option
        if (this._maxElemsToParse > 0) {
          var numTags = this._doc.getElementsByTagName("*").length;
          if (numTags > this._maxElemsToParse) {
            throw new Error("Aborting parsing document; " + numTags + " elements found");
          }
        }
    
        // 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._articleTitle = metadata.title;
    
        var articleContent = this._grabArticle();
        if (!articleContent)
          return null;
    
        this.log("Grabbed: " + articleContent.innerHTML);
    
        this._postProcessContent(articleContent);
    
        // If we haven't found an excerpt in the article's metadata, use the article's
        // first paragraph as the excerpt. This is used for displaying a preview of
        // the article's content.
        if (!metadata.excerpt) {
          var paragraphs = articleContent.getElementsByTagName("p");
          if (paragraphs.length > 0) {
            metadata.excerpt = paragraphs[0].textContent.trim();
          }
        }
    
        var textContent = articleContent.textContent;
        return {
          title: this._articleTitle,
          byline: metadata.byline || this._articleByline,
          dir: this._articleDir,
          lang: this._articleLang,
          content: this._serializer(articleContent),
          textContent: textContent,
          length: textContent.length,
          excerpt: metadata.excerpt,
          siteName: metadata.siteName || this._articleSiteName
        };
      }
    };
    
    if (typeof module === "object") {
      module.exports = Readability;
    }
    
    
    const article = new Readability(window.document.cloneNode(true)).parse();
    const utterance = new SpeechSynthesisUtterance(article.textContent.trim());
    utterance.lang = document.documentElement.lang;
    speechSynthesis.speak(utterance);
  • Permalink
    このページへの個別リンクです。
    RAW
    書かれたコードへの直接のリンクです。
    Packed
    文字列が圧縮された書かれたコードへのリンクです。
    Userscript
    Greasemonkey 等で利用する場合の .user.js へのリンクです。
    Loader
    @require やソースコードが長い場合に多段ロードする Loader コミのコードへのリンクです。
    Metadata
    コード中にコメントで @xxx と書かれたメタデータの JSON です。