diff --git a/README.md b/README.md index 00b4d18..3808095 100644 --- a/README.md +++ b/README.md @@ -45,6 +45,15 @@ var documentClone = document.cloneNode(true); var article = new Readability(documentClone).parse(); ``` +## What's Readability-readerable? + +It's a quick-and-dirty way of figuring out if it's plausible that the contents of a given +document are suitable for processing with Readability. It is likely to produce both false +positives and false negatives. The reason it exists is to avoid bogging down a time-sensitive +process (like loading and showing the user a webpage) with the complex logic in the core of +Readability. Improvements to its logic (while not deteriorating its performance) are very +welcome. + ## Tests Please run [eslint](http://eslint.org/) as a first check that your changes adhere to our style guidelines. diff --git a/Readability-readerable.js b/Readability-readerable.js new file mode 100644 index 0000000..3be56d4 --- /dev/null +++ b/Readability-readerable.js @@ -0,0 +1,97 @@ +/* eslint-env es6:false */ +/* globals exports */ +/* + * Copyright (c) 2010 Arc90 Inc + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * This code is heavily based on Arc90's readability.js (1.7.1) script + * available at: http://code.google.com/p/arc90labs-readability + */ + +var REGEXPS = { + // NOTE: These two regular expressions are duplicated in + // Readability.js. Please keep both copies in sync. + unlikelyCandidates: /-ad-|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|foot|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote/i, + okMaybeItsACandidate: /and|article|body|column|main|shadow/i, +}; + +function isNodeVisible(node) { + // Have to null-check node.style to deal with SVG and MathML nodes. + return (!node.style || node.style.display != "none") && !node.hasAttribute("hidden"); +} + +/** + * Decides whether or not the document is reader-able without parsing the whole thing. + * + * @return boolean Whether or not we suspect Readability.parse() will suceeed at returning an article object. + */ +function isProbablyReaderable(doc, isVisible) { + if (!isVisible) { + isVisible = isNodeVisible; + } + + var nodes = doc.querySelectorAll("p, pre"); + + // Get