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Readability.js
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/*jslint undef: true, nomen: true, eqeqeq: true, plusplus: true, newcap: true, immed: true, browser: true, devel: true, passfail: false */ | |
/*global window: false, readConvertLinksToFootnotes: false, readStyle: false, readSize: false, readMargin: false, Typekit: false, ActiveXObject: false */ | |
var dbg = (typeof console !== 'undefined') ? function(s) { | |
console.log("Readability: " + s); | |
} : function() {}; | |
/* | |
* Readability. An Arc90 Lab Experiment. | |
* Website: http://lab.arc90.com/experiments/readability | |
* Source: http://code.google.com/p/arc90labs-readability | |
* | |
* "Readability" is a trademark of Arc90 Inc and may not be used without explicit permission. | |
* | |
* Copyright (c) 2010 Arc90 Inc | |
* Readability is licensed under the Apache License, Version 2.0. | |
**/ | |
var readability = { | |
version: '1.7.1', | |
emailSrc: 'http://lab.arc90.com/experiments/readability/email.php', | |
iframeLoads: 0, | |
convertLinksToFootnotes: false, | |
reversePageScroll: false, /* If they hold shift and hit space, scroll up */ | |
frameHack: false, /** | |
* The frame hack is to workaround a firefox bug where if you | |
* pull content out of a frame and stick it into the parent element, the scrollbar won't appear. | |
* So we fake a scrollbar in the wrapping div. | |
**/ | |
biggestFrame: false, | |
bodyCache: null, /* Cache the body HTML in case we need to re-use it later */ | |
flags: 0x1 | 0x2 | 0x4, /* Start with all flags set. */ | |
/* constants */ | |
FLAG_STRIP_UNLIKELYS: 0x1, | |
FLAG_WEIGHT_CLASSES: 0x2, | |
FLAG_CLEAN_CONDITIONALLY: 0x4, | |
maxPages: 30, /* The maximum number of pages to loop through before we call it quits and just show a link. */ | |
parsedPages: {}, /* The list of pages we've parsed in this call of readability, for autopaging. As a key store for easier searching. */ | |
pageETags: {}, /* A list of the ETag headers of pages we've parsed, in case they happen to match, we'll know it's a duplicate. */ | |
/** | |
* All of the regular expressions in use within readability. | |
* Defined up here so we don't instantiate them repeatedly in loops. | |
**/ | |
regexps: { | |
unlikelyCandidates: /combx|comment|community|disqus|extra|foot|header|menu|remark|rss|shoutbox|sidebar|sponsor|ad-break|agegate|pagination|pager|popup|tweet|twitter/i, | |
okMaybeItsACandidate: /and|article|body|column|main|shadow/i, | |
positive: /article|body|content|entry|hentry|main|page|pagination|post|text|blog|story/i, | |
negative: /combx|comment|com-|contact|foot|footer|footnote|masthead|media|meta|outbrain|promo|related|scroll|shoutbox|sidebar|sponsor|shopping|tags|tool|widget/i, | |
extraneous: /print|archive|comment|discuss|e[\-]?mail|share|reply|all|login|sign|single/i, | |
divToPElements: /<(a|blockquote|dl|div|img|ol|p|pre|table|ul)/i, | |
replaceBrs: /(<br[^>]*>[ \n\r\t]*){2,}/gi, | |
replaceFonts: /<(\/?)font[^>]*>/gi, | |
trim: /^\s+|\s+$/g, | |
normalize: /\s{2,}/g, | |
killBreaks: /(<br\s*\/?>(\s| ?)*){1,}/g, | |
videos: /http:\/\/(www\.)?(youtube|vimeo)\.com/i, | |
skipFootnoteLink: /^\s*(\[?[a-z0-9]{1,2}\]?|^|edit|citation needed)\s*$/i, | |
nextLink: /(next|weiter|continue|>([^\|]|$)|»([^\|]|$))/i, // Match: next, continue, >, >>, » but not >|, »| as those usually mean last. | |
prevLink: /(prev|earl|old|new|<|«)/i | |
}, | |
/** | |
* Runs readability. | |
* | |
* Workflow: | |
* 1. Prep the document by removing script tags, css, etc. | |
* 2. Build readability's DOM tree. | |
* 3. Grab the article content from the current dom tree. | |
* 4. Replace the current DOM tree with the new one. | |
* 5. Read peacefully. | |
* | |
* @return void | |
**/ | |
init: function() { | |
/* Before we do anything, remove all scripts that are not readability. */ | |
window.onload = window.onunload = function() {}; | |
readability.removeScripts(document); | |
if(document.body && !readability.bodyCache) { | |
readability.bodyCache = document.body.innerHTML; | |
} | |
/* Make sure this document is added to the list of parsed pages first, so we don't double up on the first page */ | |
readability.parsedPages[window.location.href.replace(/\/$/, '')] = true; | |
/* Pull out any possible next page link first */ | |
var nextPageLink = readability.findNextPageLink(document.body); | |
readability.prepDocument(); | |
/* Build readability's DOM tree */ | |
var overlay = document.createElement("DIV"); | |
var innerDiv = document.createElement("DIV"); | |
var articleTools = readability.getArticleTools(); | |
var articleTitle = readability.getArticleTitle(); | |
var articleContent = readability.grabArticle(); | |
var articleFooter = readability.getArticleFooter(); | |
if(!articleContent) { | |
articleContent = document.createElement("DIV"); | |
articleContent.id = "readability-content"; | |
articleContent.innerHTML = [ | |
"<p>Sorry, readability was unable to parse this page for content. If you feel like it should have been able to, please <a href='http://code.google.com/p/arc90labs-readability/issues/entry'>let us know by submitting an issue.</a></p>", | |
(readability.frameHack ? "<p><strong>It appears this page uses frames.</strong> Unfortunately, browser security properties often cause Readability to fail on pages that include frames. You may want to try running readability itself on this source page: <a href='" + readability.biggestFrame.src + "'>" + readability.biggestFrame.src + "</a></p>" : ""), | |
"<p>Also, please note that Readability does not play very nicely with front pages. Readability is intended to work on articles with a sizable chunk of text that you'd like to read comfortably. If you're using Readability on a landing page (like nytimes.com for example), please click into an article first before using Readability.</p>" | |
].join(''); | |
nextPageLink = null; | |
} | |
overlay.id = "readOverlay"; | |
innerDiv.id = "readInner"; | |
/* Apply user-selected styling */ | |
document.body.className = readStyle; | |
document.dir = readability.getSuggestedDirection(articleTitle.innerHTML); | |
if (readStyle === "style-athelas" || readStyle === "style-apertura"){ | |
overlay.className = readStyle + " rdbTypekit"; | |
} | |
else { | |
overlay.className = readStyle; | |
} | |
innerDiv.className = readMargin + " " + readSize; | |
if(typeof(readConvertLinksToFootnotes) !== 'undefined' && readConvertLinksToFootnotes === true) { | |
readability.convertLinksToFootnotes = true; | |
} | |
/* Glue the structure of our document together. */ | |
innerDiv.appendChild( articleTitle ); | |
innerDiv.appendChild( articleContent ); | |
innerDiv.appendChild( articleFooter ); | |
overlay.appendChild( articleTools ); | |
overlay.appendChild( innerDiv ); | |
/* Clear the old HTML, insert the new content. */ | |
document.body.innerHTML = ""; | |
document.body.insertBefore(overlay, document.body.firstChild); | |
document.body.removeAttribute('style'); | |
if(readability.frameHack) | |
{ | |
var readOverlay = document.getElementById('readOverlay'); | |
readOverlay.style.height = '100%'; | |
readOverlay.style.overflow = 'auto'; | |
} | |
/** | |
* If someone tries to use Readability on a site's root page, give them a warning about usage. | |
**/ | |
if((window.location.protocol + "//" + window.location.host + "/") === window.location.href) | |
{ | |
articleContent.style.display = "none"; | |
var rootWarning = document.createElement('p'); | |
rootWarning.id = "readability-warning"; | |
rootWarning.innerHTML = "<em>Readability</em> was intended for use on individual articles and not home pages. " + | |
"If you'd like to try rendering this page anyway, <a onClick='javascript:document.getElementById(\"readability-warning\").style.display=\"none\";document.getElementById(\"readability-content\").style.display=\"block\";'>click here</a> to continue."; | |
innerDiv.insertBefore( rootWarning, articleContent ); | |
} | |
readability.postProcessContent(articleContent); | |
window.scrollTo(0, 0); | |
/* If we're using the Typekit library, select the font */ | |
if (readStyle === "style-athelas" || readStyle === "style-apertura") { | |
readability.useRdbTypekit(); | |
} | |
if (nextPageLink) { | |
/** | |
* Append any additional pages after a small timeout so that people | |
* can start reading without having to wait for this to finish processing. | |
**/ | |
window.setTimeout(function() { | |
readability.appendNextPage(nextPageLink); | |
}, 500); | |
} | |
/** Smooth scrolling **/ | |
document.onkeydown = function(e) { | |
var code = (window.event) ? event.keyCode : e.keyCode; | |
if (code === 16) { | |
readability.reversePageScroll = true; | |
return; | |
} | |
if (code === 32) { | |
readability.curScrollStep = 0; | |
var windowHeight = window.innerHeight ? window.innerHeight : (document.documentElement.clientHeight ? document.documentElement.clientHeight : document.body.clientHeight); | |
if(readability.reversePageScroll) { | |
readability.scrollTo(readability.scrollTop(), readability.scrollTop() - (windowHeight - 50), 20, 10); | |
} | |
else { | |
readability.scrollTo(readability.scrollTop(), readability.scrollTop() + (windowHeight - 50), 20, 10); | |
} | |
return false; | |
} | |
}; | |
document.onkeyup = function(e) { | |
var code = (window.event) ? event.keyCode : e.keyCode; | |
if (code === 16) { | |
readability.reversePageScroll = false; | |
return; | |
} | |
}; | |
}, | |
/** | |
* Run any post-process modifications to article content as necessary. | |
* | |
* @param Element | |
* @return void | |
**/ | |
postProcessContent: function(articleContent) { | |
if(readability.convertLinksToFootnotes && !window.location.href.match(/wikipedia\.org/g)) { | |
readability.addFootnotes(articleContent); | |
} | |
readability.fixImageFloats(articleContent); | |
}, | |
/** | |
* Some content ends up looking ugly if the image is too large to be floated. | |
* If the image is wider than a threshold (currently 55%), no longer float it, | |
* center it instead. | |
* | |
* @param Element | |
* @return void | |
**/ | |
fixImageFloats: function (articleContent) { | |
var imageWidthThreshold = Math.min(articleContent.offsetWidth, 800) * 0.55, | |
images = articleContent.getElementsByTagName('img'); | |
for(var i=0, il = images.length; i < il; i+=1) { | |
var image = images[i]; | |
if(image.offsetWidth > imageWidthThreshold) { | |
image.className += " blockImage"; | |
} | |
} | |
}, | |
/** | |
* Get the article tools Element that has buttons like reload, print, email. | |
* | |
* @return void | |
**/ | |
getArticleTools: function () { | |
var articleTools = document.createElement("DIV"); | |
articleTools.id = "readTools"; | |
articleTools.innerHTML = | |
"<a href='#' onclick='return window.location.reload()' title='Reload original page' id='reload-page'>Reload Original Page</a>" + | |
"<a href='#' onclick='javascript:window.print();' title='Print page' id='print-page'>Print Page</a>" + | |
"<a href='#' onclick='readability.emailBox(); return false;' title='Email page' id='email-page'>Email Page</a>"; | |
return articleTools; | |
}, | |
/** | |
* retuns the suggested direction of the string | |
* | |
* @return "rtl" || "ltr" | |
**/ | |
getSuggestedDirection: function(text) { | |
function sanitizeText() { | |
return text.replace(/@\w+/, ""); | |
} | |
function countMatches(match) { | |
var matches = text.match(new RegExp(match, "g")); | |
return matches !== null ? matches.length : 0; | |
} | |
function isRTL() { | |
var count_heb = countMatches("[\\u05B0-\\u05F4\\uFB1D-\\uFBF4]"); | |
var count_arb = countMatches("[\\u060C-\\u06FE\\uFB50-\\uFEFC]"); | |
// if 20% of chars are Hebrew or Arbic then direction is rtl | |
return (count_heb + count_arb) * 100 / text.length > 20; | |
} | |
text = sanitizeText(text); | |
return isRTL() ? "rtl" : "ltr"; | |
}, | |
/** | |
* Get the article title as an H1. | |
* | |
* @return void | |
**/ | |
getArticleTitle: function () { | |
var curTitle = "", | |
origTitle = ""; | |
try { | |
curTitle = origTitle = document.title; | |
if(typeof curTitle !== "string") { /* If they had an element with id "title" in their HTML */ | |
curTitle = origTitle = readability.getInnerText(document.getElementsByTagName('title')[0]); | |
} | |
} | |
catch(e) {} | |
if(curTitle.match(/ [\|\-] /)) | |
{ | |
curTitle = origTitle.replace(/(.*)[\|\-] .*/gi,'$1'); | |
if(curTitle.split(' ').length < 3) { | |
curTitle = origTitle.replace(/[^\|\-]*[\|\-](.*)/gi,'$1'); | |
} | |
} | |
else if(curTitle.indexOf(': ') !== -1) | |
{ | |
curTitle = origTitle.replace(/.*:(.*)/gi, '$1'); | |
if(curTitle.split(' ').length < 3) { | |
curTitle = origTitle.replace(/[^:]*[:](.*)/gi,'$1'); | |
} | |
} | |
else if(curTitle.length > 150 || curTitle.length < 15) | |
{ | |
var hOnes = document.getElementsByTagName('h1'); | |
if(hOnes.length === 1) | |
{ | |
curTitle = readability.getInnerText(hOnes[0]); | |
} | |
} | |
curTitle = curTitle.replace( readability.regexps.trim, "" ); | |
if(curTitle.split(' ').length <= 4) { | |
curTitle = origTitle; | |
} | |
var articleTitle = document.createElement("H1"); | |
articleTitle.innerHTML = curTitle; | |
return articleTitle; | |
}, | |
/** | |
* Get the footer with the readability mark etc. | |
* | |
* @return void | |
**/ | |
getArticleFooter: function () { | |
var articleFooter = document.createElement("DIV"); | |
/** | |
* For research purposes, generate an img src that contains the chosen readstyle etc, | |
* so we can generate aggregate stats and change styles based on them in the future | |
**/ | |
// var statsQueryParams = "?readStyle=" + encodeURIComponent(readStyle) + "&readMargin=" + encodeURIComponent(readMargin) + "&readSize=" + encodeURIComponent(readSize); | |
/* TODO: attach this to an image */ | |
articleFooter.id = "readFooter"; | |
articleFooter.innerHTML = [ | |
"<div id='rdb-footer-print'>Excerpted from <cite>" + document.title + "</cite><br />" + window.location.href + "</div>", | |
"<div id='rdb-footer-wrapper'>", | |
"<div id='rdb-footer-left'>", | |
"<a href='http://lab.arc90.com/experiments/readability' id='readability-logo'>Readability — </a>", | |
"<a href='http://www.arc90.com/' id='arc90-logo'> An Arc90 Laboratory Experiment </a>", | |
" <span id='readability-url'> http://lab.arc90.com/experiments/readability</span>", | |
"</div>", | |
"<div id='rdb-footer-right'>", | |
"<a href='http://www.twitter.com/arc90' class='footer-twitterLink'>Follow us on Twitter »</a>", | |
"<span class='version'>Readability version " + readability.version + "</span>", | |
"</div>", | |
"</div>"].join(''); | |
return articleFooter; | |
}, | |
/** | |
* Prepare the HTML document for readability to scrape it. | |
* This includes things like stripping javascript, CSS, and handling terrible markup. | |
* | |
* @return void | |
**/ | |
prepDocument: function () { | |
/** | |
* In some cases a body element can't be found (if the HTML is totally hosed for example) | |
* so we create a new body node and append it to the document. | |
*/ | |
if(document.body === null) | |
{ | |
var body = document.createElement("body"); | |
try { | |
document.body = body; | |
} | |
catch(e) { | |
document.documentElement.appendChild(body); | |
dbg(e); | |
} | |
} | |
document.body.id = "readabilityBody"; | |
var frames = document.getElementsByTagName('frame'); | |
if(frames.length > 0) | |
{ | |
var bestFrame = null; | |
var bestFrameSize = 0; /* The frame to try to run readability upon. Must be on same domain. */ | |
var biggestFrameSize = 0; /* Used for the error message. Can be on any domain. */ | |
for(var frameIndex = 0; frameIndex < frames.length; frameIndex+=1) | |
{ | |
var frameSize = frames[frameIndex].offsetWidth + frames[frameIndex].offsetHeight; | |
var canAccessFrame = false; | |
try { | |
var frameBody = frames[frameIndex].contentWindow.document.body; | |
canAccessFrame = true; | |
} | |
catch(eFrames) { | |
dbg(eFrames); | |
} | |
if(frameSize > biggestFrameSize) { | |
biggestFrameSize = frameSize; | |
readability.biggestFrame = frames[frameIndex]; | |
} | |
if(canAccessFrame && frameSize > bestFrameSize) | |
{ | |
readability.frameHack = true; | |
bestFrame = frames[frameIndex]; | |
bestFrameSize = frameSize; | |
} | |
} | |
if(bestFrame) | |
{ | |
var newBody = document.createElement('body'); | |
newBody.innerHTML = bestFrame.contentWindow.document.body.innerHTML; | |
newBody.style.overflow = 'scroll'; | |
document.body = newBody; | |
var frameset = document.getElementsByTagName('frameset')[0]; | |
if(frameset) { | |
frameset.parentNode.removeChild(frameset); } | |
} | |
} | |
/* Remove all stylesheets */ | |
for (var k=0;k < document.styleSheets.length; k+=1) { | |
if (document.styleSheets[k].href !== null && document.styleSheets[k].href.lastIndexOf("readability") === -1) { | |
document.styleSheets[k].disabled = true; | |
} | |
} | |
/* Remove all style tags in head (not doing this on IE) - TODO: Why not? */ | |
var styleTags = document.getElementsByTagName("style"); | |
for (var st=0;st < styleTags.length; st+=1) { | |
styleTags[st].textContent = ""; | |
} | |
/* Turn all double br's into p's */ | |
/* Note, this is pretty costly as far as processing goes. Maybe optimize later. */ | |
document.body.innerHTML = document.body.innerHTML.replace(readability.regexps.replaceBrs, '</p><p>').replace(readability.regexps.replaceFonts, '<$1span>'); | |
}, | |
/** | |
* For easier reading, convert this document to have footnotes at the bottom rather than inline links. | |
* @see http://www.roughtype.com/archives/2010/05/experiments_in.php | |
* | |
* @return void | |
**/ | |
addFootnotes: function(articleContent) { | |
var footnotesWrapper = document.getElementById('readability-footnotes'), | |
articleFootnotes = document.getElementById('readability-footnotes-list'); | |
if(!footnotesWrapper) { | |
footnotesWrapper = document.createElement("DIV"); | |
footnotesWrapper.id = 'readability-footnotes'; | |
footnotesWrapper.innerHTML = '<h3>References</h3>'; | |
footnotesWrapper.style.display = 'none'; /* Until we know we have footnotes, don't show the references block. */ | |
articleFootnotes = document.createElement('ol'); | |
articleFootnotes.id = 'readability-footnotes-list'; | |
footnotesWrapper.appendChild(articleFootnotes); | |
var readFooter = document.getElementById('readFooter'); | |
if(readFooter) { | |
readFooter.parentNode.insertBefore(footnotesWrapper, readFooter); | |
} | |
} | |
var articleLinks = articleContent.getElementsByTagName('a'); | |
var linkCount = articleFootnotes.getElementsByTagName('li').length; | |
for (var i = 0; i < articleLinks.length; i+=1) | |
{ | |
var articleLink = articleLinks[i], | |
footnoteLink = articleLink.cloneNode(true), | |
refLink = document.createElement('a'), | |
footnote = document.createElement('li'), | |
linkDomain = footnoteLink.host ? footnoteLink.host : document.location.host, | |
linkText = readability.getInnerText(articleLink); | |
if(articleLink.className && articleLink.className.indexOf('readability-DoNotFootnote') !== -1 || linkText.match(readability.regexps.skipFootnoteLink)) { | |
continue; | |
} | |
linkCount+=1; | |
/** Add a superscript reference after the article link */ | |
refLink.href = '#readabilityFootnoteLink-' + linkCount; | |
refLink.innerHTML = '<small><sup>[' + linkCount + ']</sup></small>'; | |
refLink.className = 'readability-DoNotFootnote'; | |
try { refLink.style.color = 'inherit'; } catch(e) {} /* IE7 doesn't like inherit. */ | |
if(articleLink.parentNode.lastChild === articleLink) { | |
articleLink.parentNode.appendChild(refLink); | |
} else { | |
articleLink.parentNode.insertBefore(refLink, articleLink.nextSibling); | |
} | |
articleLink.name = 'readabilityLink-' + linkCount; | |
try { articleLink.style.color = 'inherit'; } catch(err) {} /* IE7 doesn't like inherit. */ | |
footnote.innerHTML = "<small><sup><a href='#readabilityLink-" + linkCount + "' title='Jump to Link in Article'>^</a></sup></small> "; | |
footnoteLink.innerHTML = (footnoteLink.title ? footnoteLink.title : linkText); | |
footnoteLink.name = 'readabilityFootnoteLink-' + linkCount; | |
footnote.appendChild(footnoteLink); | |
footnote.innerHTML = footnote.innerHTML + "<small> (" + linkDomain + ")</small>"; | |
articleFootnotes.appendChild(footnote); | |
} | |
if(linkCount > 0) { | |
footnotesWrapper.style.display = 'block'; | |
} | |
}, | |
useRdbTypekit: function () { | |
var rdbHead = document.getElementsByTagName('head')[0]; | |
var rdbTKScript = document.createElement('script'); | |
var rdbTKCode = null; | |
var rdbTKLink = document.createElement('a'); | |
rdbTKLink.setAttribute('class','rdbTK-powered'); | |
rdbTKLink.setAttribute('title','Fonts by Typekit'); | |
rdbTKLink.innerHTML = "Fonts by <span class='rdbTK'>Typekit</span>"; | |
if (readStyle === "style-athelas") { | |
rdbTKCode = "sxt6vzy"; | |
dbg("Using Athelas Theme"); | |
rdbTKLink.setAttribute('href','http://typekit.com/?utm_source=readability&utm_medium=affiliate&utm_campaign=athelas'); | |
rdbTKLink.setAttribute('id','rdb-athelas'); | |
document.getElementById("rdb-footer-right").appendChild(rdbTKLink); | |
} | |
if (readStyle === "style-apertura") { | |
rdbTKCode = "bae8ybu"; | |
dbg("Using Inverse Theme"); | |
rdbTKLink.setAttribute('href','http://typekit.com/?utm_source=readability&utm_medium=affiliate&utm_campaign=inverse'); | |
rdbTKLink.setAttribute('id','rdb-inverse'); | |
document.getElementById("rdb-footer-right").appendChild(rdbTKLink); | |
} | |
/** | |
* Setting new script tag attributes to pull Typekits libraries | |
**/ | |
rdbTKScript.setAttribute('type','text/javascript'); | |
rdbTKScript.setAttribute('src',"http://use.typekit.com/" + rdbTKCode + ".js"); | |
rdbTKScript.setAttribute('charset','UTF-8'); | |
rdbHead.appendChild(rdbTKScript); | |
/** | |
* In the future, maybe try using the following experimental Callback function?: | |
* http://gist.github.com/192350 | |
* & | |
* http://getsatisfaction.com/typekit/topics/support_a_pre_and_post_load_callback_function | |
**/ | |
var typekitLoader = function() { | |
dbg("Looking for Typekit."); | |
if(typeof Typekit !== "undefined") { | |
try { | |
dbg("Caught typekit"); | |
Typekit.load(); | |
clearInterval(window.typekitInterval); | |
} catch(e) { | |
dbg("Typekit error: " + e); | |
} | |
} | |
}; | |
window.typekitInterval = window.setInterval(typekitLoader, 100); | |
}, | |
/** | |
* 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) { | |
readability.cleanStyles(articleContent); | |
readability.killBreaks(articleContent); | |
/* Clean out junk from the article content */ | |
readability.cleanConditionally(articleContent, "form"); | |
readability.clean(articleContent, "object"); | |
readability.clean(articleContent, "h1"); | |
/** | |
* If there is only one h2, they are probably using it | |
* as a header and not a subheader, so remove it since we already have a header. | |
***/ | |
if(articleContent.getElementsByTagName('h2').length === 1) { | |
readability.clean(articleContent, "h2"); | |
} | |
readability.clean(articleContent, "iframe"); | |
readability.cleanHeaders(articleContent); | |
/* Do these last as the previous stuff may have removed junk that will affect these */ | |
readability.cleanConditionally(articleContent, "table"); | |
readability.cleanConditionally(articleContent, "ul"); | |
readability.cleanConditionally(articleContent, "div"); | |
/* Remove extra paragraphs */ | |
var articleParagraphs = articleContent.getElementsByTagName('p'); | |
for(var i = articleParagraphs.length-1; i >= 0; i-=1) { | |
var imgCount = articleParagraphs[i].getElementsByTagName('img').length; | |
var embedCount = articleParagraphs[i].getElementsByTagName('embed').length; | |
var objectCount = articleParagraphs[i].getElementsByTagName('object').length; | |
if(imgCount === 0 && embedCount === 0 && objectCount === 0 && readability.getInnerText(articleParagraphs[i], false) === '') { | |
articleParagraphs[i].parentNode.removeChild(articleParagraphs[i]); | |
} | |
} | |
try { | |
articleContent.innerHTML = articleContent.innerHTML.replace(/<br[^>]*>\s*<p/gi, '<p'); | |
} | |
catch (e) { | |
dbg("Cleaning innerHTML of breaks failed. This is an IE strict-block-elements bug. Ignoring.: " + e); | |
} | |
}, | |
/** | |
* 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 += readability.getClassWeight(node); | |
}, | |
/*** | |
* 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) { | |
var stripUnlikelyCandidates = readability.flagIsActive(readability.FLAG_STRIP_UNLIKELYS), | |
isPaging = (page !== null) ? true: false; | |
page = page ? page : document.body; | |
var pageCacheHtml = page.innerHTML; | |
var allElements = page.getElementsByTagName('*'); | |
/** | |
* 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.) | |
* | |
* Note: Assignment from index for performance. See http://www.peachpit.com/articles/article.aspx?p=31567&seqNum=5 | |
* TODO: Shouldn't this be a reverse traversal? | |
**/ | |
var node = null; | |
var nodesToScore = []; | |
for(var nodeIndex = 0; (node = allElements[nodeIndex]); nodeIndex+=1) { | |
/* Remove unlikely candidates */ | |
if (stripUnlikelyCandidates) { | |
var unlikelyMatchString = node.className + node.id; | |
if ( | |
( | |
unlikelyMatchString.search(readability.regexps.unlikelyCandidates) !== -1 && | |
unlikelyMatchString.search(readability.regexps.okMaybeItsACandidate) === -1 && | |
node.tagName !== "BODY" | |
) | |
) | |
{ | |
dbg("Removing unlikely candidate - " + unlikelyMatchString); | |
node.parentNode.removeChild(node); | |
nodeIndex-=1; | |
continue; | |
} | |
} | |
if (node.tagName === "P" || node.tagName === "TD" || node.tagName === "PRE") { | |
nodesToScore[nodesToScore.length] = node; | |
} | |
/* Turn all divs that don't have children block level elements into p's */ | |
if (node.tagName === "DIV") { | |
if (node.innerHTML.search(readability.regexps.divToPElements) === -1) { | |
var newNode = document.createElement('p'); | |
try { | |
newNode.innerHTML = node.innerHTML; | |
node.parentNode.replaceChild(newNode, node); | |
nodeIndex-=1; | |
nodesToScore[nodesToScore.length] = node; | |
} | |
catch(e) { | |
dbg("Could not alter div to p, probably an IE restriction, reverting back to div.: " + e); | |
} | |
} | |
else | |
{ | |
/* EXPERIMENTAL */ | |
for(var i = 0, il = node.childNodes.length; i < il; i+=1) { | |
var childNode = node.childNodes[i]; | |
if(childNode.nodeType === 3) { // Node.TEXT_NODE | |
var p = document.createElement('p'); | |
p.innerHTML = childNode.nodeValue; | |
p.style.display = 'inline'; | |
p.className = 'readability-styled'; | |
childNode.parentNode.replaceChild(p, childNode); | |
} | |
} | |
} | |
} | |
} | |
/** | |
* 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 = []; | |
for (var pt=0; pt < nodesToScore.length; pt+=1) { | |
var parentNode = nodesToScore[pt].parentNode; | |
var grandParentNode = parentNode ? parentNode.parentNode : null; | |
var innerText = readability.getInnerText(nodesToScore[pt]); | |
if(!parentNode || typeof(parentNode.tagName) === 'undefined') { | |
continue; | |
} | |
/* If this paragraph is less than 25 characters, don't even count it. */ | |
if(innerText.length < 25) { | |
continue; } | |
/* Initialize readability data for the parent. */ | |
if(typeof parentNode.readability === 'undefined') { | |
readability.initializeNode(parentNode); | |
candidates.push(parentNode); | |
} | |
/* Initialize readability data for the grandparent. */ | |
if(grandParentNode && typeof(grandParentNode.readability) === 'undefined' && typeof(grandParentNode.tagName) !== 'undefined') { | |
readability.initializeNode(grandParentNode); | |
candidates.push(grandParentNode); | |
} | |
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); | |
/* Add the score to the parent. The grandparent gets half. */ | |
parentNode.readability.contentScore += contentScore; | |
if(grandParentNode) { | |
grandParentNode.readability.contentScore += contentScore/2; | |
} | |
} | |
/** | |
* After we've calculated scores, loop through all of the possible candidate nodes we found | |
* and find the one with the highest score. | |
**/ | |
var topCandidate = null; | |
for(var c=0, cl=candidates.length; c < cl; c+=1) | |
{ | |
/** | |
* 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. | |
**/ | |
candidates[c].readability.contentScore = candidates[c].readability.contentScore * (1-readability.getLinkDensity(candidates[c])); | |
dbg('Candidate: ' + candidates[c] + " (" + candidates[c].className + ":" + candidates[c].id + ") with score " + candidates[c].readability.contentScore); | |
if(!topCandidate || candidates[c].readability.contentScore > topCandidate.readability.contentScore) { | |
topCandidate = candidates[c]; } | |
} | |
/** | |
* 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") | |
{ | |
topCandidate = document.createElement("DIV"); | |
topCandidate.innerHTML = page.innerHTML; | |
page.innerHTML = ""; | |
page.appendChild(topCandidate); | |
readability.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 = document.createElement("DIV"); | |
if (isPaging) { | |
articleContent.id = "readability-content"; | |
} | |
var siblingScoreThreshold = Math.max(10, topCandidate.readability.contentScore * 0.2); | |
var siblingNodes = topCandidate.parentNode.childNodes; | |
for(var s=0, sl=siblingNodes.length; s < sl; s+=1) { | |
var siblingNode = siblingNodes[s]; | |
var append = false; | |
/** | |
* Fix for odd IE7 Crash where siblingNode does not exist even though this should be a live nodeList. | |
* Example of error visible here: http://www.esquire.com/features/honesty0707 | |
**/ | |
if(!siblingNode) { | |
continue; | |
} | |
dbg("Looking at sibling node: " + siblingNode + " (" + siblingNode.className + ":" + siblingNode.id + ")" + ((typeof siblingNode.readability !== 'undefined') ? (" with score " + siblingNode.readability.contentScore) : '')); | |
dbg("Sibling has score " + (siblingNode.readability ? siblingNode.readability.contentScore : 'Unknown')); | |
if(siblingNode === topCandidate) | |
{ | |
append = true; | |
} | |
var contentBonus = 0; | |
/* Give a bonus if sibling nodes and top candidates have the example same classname */ | |
if(siblingNode.className === topCandidate.className && topCandidate.className !== "") { | |
contentBonus += topCandidate.readability.contentScore * 0.2; | |
} | |
if(typeof siblingNode.readability !== 'undefined' && (siblingNode.readability.contentScore+contentBonus) >= siblingScoreThreshold) | |
{ | |
append = true; | |
} | |
if(siblingNode.nodeName === "P") { | |
var linkDensity = readability.getLinkDensity(siblingNode); | |
var nodeContent = readability.getInnerText(siblingNode); | |
var nodeLength = nodeContent.length; | |
if(nodeLength > 80 && linkDensity < 0.25) | |
{ | |
append = true; | |
} | |
else if(nodeLength < 80 && linkDensity === 0 && nodeContent.search(/\.( |$)/) !== -1) | |
{ | |
append = true; | |
} | |
} | |
if(append) { | |
dbg("Appending node: " + siblingNode); | |
var nodeToAppend = null; | |
if(siblingNode.nodeName !== "DIV" && siblingNode.nodeName !== "P") { | |
/* 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. */ | |
dbg("Altering siblingNode of " + siblingNode.nodeName + ' to div.'); | |
nodeToAppend = document.createElement("DIV"); | |
try { | |
nodeToAppend.id = siblingNode.id; | |
nodeToAppend.innerHTML = siblingNode.innerHTML; | |
} | |
catch(er) { | |
dbg("Could not alter siblingNode to div, probably an IE restriction, reverting back to original."); | |
nodeToAppend = siblingNode; | |
s-=1; | |
sl-=1; | |
} | |
} else { | |
nodeToAppend = siblingNode; | |
s-=1; | |
sl-=1; | |
} | |
/* To ensure a node does not interfere with readability styles, remove its classnames */ | |
nodeToAppend.className = ""; | |
/* Append sibling and subtract from our list because it removes the node when you append to another node */ | |
articleContent.appendChild(nodeToAppend); | |
} | |
} | |
/** | |
* So we have all of the content that we need. Now we clean it up for presentation. | |
**/ | |
readability.prepArticle(articleContent); | |
if (readability.curPageNum === 1) { | |
articleContent.innerHTML = '<div id="readability-page-1" class="page">' + articleContent.innerHTML + '</div>'; | |
} | |
/** | |
* 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. | |
**/ | |
if(readability.getInnerText(articleContent, false).length < 250) { | |
page.innerHTML = pageCacheHtml; | |
if (readability.flagIsActive(readability.FLAG_STRIP_UNLIKELYS)) { | |
readability.removeFlag(readability.FLAG_STRIP_UNLIKELYS); | |
return readability.grabArticle(page); | |
} | |
else if (readability.flagIsActive(readability.FLAG_WEIGHT_CLASSES)) { | |
readability.removeFlag(readability.FLAG_WEIGHT_CLASSES); | |
return readability.grabArticle(page); | |
} | |
else if (readability.flagIsActive(readability.FLAG_CLEAN_CONDITIONALLY)) { | |
readability.removeFlag(readability.FLAG_CLEAN_CONDITIONALLY); | |
return readability.grabArticle(page); | |
} else { | |
return null; | |
} | |
} | |
return articleContent; | |
}, | |
/** | |
* Removes script tags from the document. | |
* | |
* @param Element | |
**/ | |
removeScripts: function (doc) { | |
var scripts = doc.getElementsByTagName('script'); | |
for(var i = scripts.length-1; i >= 0; i-=1) | |
{ | |
if(typeof(scripts[i].src) === "undefined" || (scripts[i].src.indexOf('readability') === -1 && scripts[i].src.indexOf('typekit') === -1)) | |
{ | |
scripts[i].nodeValue=""; | |
scripts[i].removeAttribute('src'); | |
if (scripts[i].parentNode) { | |
scripts[i].parentNode.removeChild(scripts[i]); | |
} | |
} | |
} | |
}, | |
/** | |
* Get the inner text of a node - cross browser compatibly. | |
* This also strips out any excess whitespace to be found. | |
* | |
* @param Element | |
* @return string | |
**/ | |
getInnerText: function (e, normalizeSpaces) { | |
var textContent = ""; | |
if(typeof(e.textContent) === "undefined" && typeof(e.innerText) === "undefined") { | |
return ""; | |
} | |
normalizeSpaces = (typeof normalizeSpaces === 'undefined') ? true : normalizeSpaces; | |
if (navigator.appName === "Microsoft Internet Explorer") { | |
textContent = e.innerText.replace( readability.regexps.trim, "" ); } | |
else { | |
textContent = e.textContent.replace( readability.regexps.trim, "" ); } | |
if(normalizeSpaces) { | |
return textContent.replace( readability.regexps.normalize, " "); } | |
else { | |
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 readability.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) { | |
e = e || document; | |
var cur = e.firstChild; | |
if(!e) { | |
return; } | |
// Remove any root styles, if we're able. | |
if(typeof e.removeAttribute === 'function' && e.className !== 'readability-styled') { | |
e.removeAttribute('style'); } | |
// Go until there are no more child nodes | |
while ( cur !== null ) { | |
if ( cur.nodeType === 1 ) { | |
// Remove style attribute(s) : | |
if(cur.className !== "readability-styled") { | |
cur.removeAttribute("style"); | |
} | |
readability.cleanStyles( cur ); | |
} | |
cur = cur.nextSibling; | |
} | |
}, | |
/** | |
* 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 (e) { | |
var links = e.getElementsByTagName("a"); | |
var textLength = readability.getInnerText(e).length; | |
var linkLength = 0; | |
for(var i=0, il=links.length; i<il;i+=1) | |
{ | |
linkLength += readability.getInnerText(links[i]).length; | |
} | |
return linkLength / textLength; | |
}, | |
/** | |
* Find a cleaned up version of the current URL, to use for comparing links for possible next-pageyness. | |
* | |
* @author Dan Lacy | |
* @return string the base url | |
**/ | |
findBaseUrl: function () { | |
var noUrlParams = window.location.pathname.split("?")[0], | |
urlSlashes = noUrlParams.split("/").reverse(), | |
cleanedSegments = [], | |
possibleType = ""; | |
for (var i = 0, slashLen = urlSlashes.length; i < slashLen; i+=1) { | |
var segment = urlSlashes[i]; | |
// Split off and save anything that looks like a file type. | |
if (segment.indexOf(".") !== -1) { | |
possibleType = segment.split(".")[1]; | |
/* If the type isn't alpha-only, it's probably not actually a file extension. */ | |
if(!possibleType.match(/[^a-zA-Z]/)) { | |
segment = segment.split(".")[0]; | |
} | |
} | |
/** | |
* EW-CMS specific segment replacement. Ugly. | |
* Example: http://www.ew.com/ew/article/0,,20313460_20369436,00.html | |
**/ | |
if(segment.indexOf(',00') !== -1) { | |
segment = segment.replace(',00', ''); | |
} | |
// If our first or second segment has anything looking like a page number, remove it. | |
if (segment.match(/((_|-)?p[a-z]*|(_|-))[0-9]{1,2}$/i) && ((i === 1) || (i === 0))) { | |
segment = segment.replace(/((_|-)?p[a-z]*|(_|-))[0-9]{1,2}$/i, ""); | |
} | |
var del = false; | |
/* If this is purely a number, and it's the first or second segment, it's probably a page number. Remove it. */ | |
if (i < 2 && segment.match(/^\d{1,2}$/)) { | |
del = true; | |
} | |
/* If this is the first segment and it's just "index", remove it. */ | |
if(i === 0 && segment.toLowerCase() === "index") { | |
del = true; | |
} | |
/* If our first or second segment is smaller than 3 characters, and the first segment was purely alphas, remove it. */ | |
if(i < 2 && segment.length < 3 && !urlSlashes[0].match(/[a-z]/i)) { | |
del = true; | |
} | |
/* If it's not marked for deletion, push it to cleanedSegments. */ | |
if (!del) { | |
cleanedSegments.push(segment); | |
} | |
} | |
// This is our final, cleaned, base article URL. | |
return window.location.protocol + "//" + window.location.host + cleanedSegments.reverse().join("/"); | |
}, | |
/** | |
* Look for any paging links that may occur within the document. | |
* | |
* @param body | |
* @return object (array) | |
**/ | |
findNextPageLink: function (elem) { | |
var possiblePages = {}, | |
allLinks = elem.getElementsByTagName('a'), | |
articleBaseUrl = readability.findBaseUrl(); | |
/** | |
* Loop through all links, looking for hints that they may be next-page links. | |
* Things like having "page" in their textContent, className or id, or being a child | |
* of a node with a page-y className or id. | |
* | |
* Also possible: levenshtein distance? longest common subsequence? | |
* | |
* After we do that, assign each page a score, and | |
**/ | |
for(var i = 0, il = allLinks.length; i < il; i+=1) { | |
var link = allLinks[i], | |
linkHref = allLinks[i].href.replace(/#.*$/, '').replace(/\/$/, ''); | |
/* If we've already seen this page, ignore it */ | |
if(linkHref === "" || linkHref === articleBaseUrl || linkHref === window.location.href || linkHref in readability.parsedPages) { | |
continue; | |
} | |
/* If it's on a different domain, skip it. */ | |
if(window.location.host !== linkHref.split(/\/+/g)[1]) { | |
continue; | |
} | |
var linkText = readability.getInnerText(link); | |
/* If the linkText looks like it's not the next page, skip it. */ | |
if(linkText.match(readability.regexps.extraneous) || linkText.length > 25) { | |
continue; | |
} | |
/* If the leftovers of the URL after removing the base URL don't contain any digits, it's certainly not a next page link. */ | |
var linkHrefLeftover = linkHref.replace(articleBaseUrl, ''); | |
if(!linkHrefLeftover.match(/\d/)) { | |
continue; | |
} | |
if(!(linkHref in possiblePages)) { | |
possiblePages[linkHref] = {"score": 0, "linkText": linkText, "href": linkHref}; | |
} else { | |
possiblePages[linkHref].linkText += ' | ' + linkText; | |
} | |
var linkObj = possiblePages[linkHref]; | |
/** | |
* If the articleBaseUrl isn't part of this URL, penalize this link. It could still be the link, but the odds are lower. | |
* Example: http://www.actionscript.org/resources/articles/745/1/JavaScript-and-VBScript-Injection-in-ActionScript-3/Page1.html | |
**/ | |
if(linkHref.indexOf(articleBaseUrl) !== 0) { | |
linkObj.score -= 25; | |
} | |
var linkData = linkText + ' ' + link.className + ' ' + link.id; | |
if(linkData.match(readability.regexps.nextLink)) { | |
linkObj.score += 50; | |
} | |
if(linkData.match(/pag(e|ing|inat)/i)) { | |
linkObj.score += 25; | |
} | |
if(linkData.match(/(first|last)/i)) { // -65 is enough to negate any bonuses gotten from a > or » in the text, | |
/* If we already matched on "next", last is probably fine. If we didn't, then it's bad. Penalize. */ | |
if(!linkObj.linkText.match(readability.regexps.nextLink)) { | |
linkObj.score -= 65; | |
} | |
} | |
if(linkData.match(readability.regexps.negative) || linkData.match(readability.regexps.extraneous)) { | |
linkObj.score -= 50; | |
} | |
if(linkData.match(readability.regexps.prevLink)) { | |
linkObj.score -= 200; | |
} | |
/* If a parentNode contains page or paging or paginat */ | |
var parentNode = link.parentNode, | |
positiveNodeMatch = false, | |
negativeNodeMatch = false; | |
while(parentNode) { | |
var parentNodeClassAndId = parentNode.className + ' ' + parentNode.id; | |
if(!positiveNodeMatch && parentNodeClassAndId && parentNodeClassAndId.match(/pag(e|ing|inat)/i)) { | |
positiveNodeMatch = true; | |
linkObj.score += 25; | |
} | |
if(!negativeNodeMatch && parentNodeClassAndId && parentNodeClassAndId.match(readability.regexps.negative)) { | |
/* If this is just something like "footer", give it a negative. If it's something like "body-and-footer", leave it be. */ | |
if(!parentNodeClassAndId.match(readability.regexps.positive)) { | |
linkObj.score -= 25; | |
negativeNodeMatch = true; | |
} | |
} | |
parentNode = parentNode.parentNode; | |
} | |
/** | |
* If the URL looks like it has paging in it, add to the score. | |
* Things like /page/2/, /pagenum/2, ?p=3, ?page=11, ?pagination=34 | |
**/ | |
if (linkHref.match(/p(a|g|ag)?(e|ing|ination)?(=|\/)[0-9]{1,2}/i) || linkHref.match(/(page|paging)/i)) { | |
linkObj.score += 25; | |
} | |
/* If the URL contains negative values, give a slight decrease. */ | |
if (linkHref.match(readability.regexps.extraneous)) { | |
linkObj.score -= 15; | |
} | |
/** | |
* Minor punishment to anything that doesn't match our current URL. | |
* NOTE: I'm finding this to cause more harm than good where something is exactly 50 points. | |
* Dan, can you show me a counterexample where this is necessary? | |
* if (linkHref.indexOf(window.location.href) !== 0) { | |
* linkObj.score -= 1; | |
* } | |
**/ | |
/** | |
* If the link text can be parsed as a number, give it a minor bonus, with a slight | |
* bias towards lower numbered pages. This is so that pages that might not have 'next' | |
* in their text can still get scored, and sorted properly by score. | |
**/ | |
var linkTextAsNumber = parseInt(linkText, 10); | |
if(linkTextAsNumber) { | |
// Punish 1 since we're either already there, or it's probably before what we want anyways. | |
if (linkTextAsNumber === 1) { | |
linkObj.score -= 10; | |
} | |
else { | |
// Todo: Describe this better | |
linkObj.score += Math.max(0, 10 - linkTextAsNumber); | |
} | |
} | |
} | |
/** | |
* Loop thrugh all of our possible pages from above and find our top candidate for the next page URL. | |
* Require at least a score of 50, which is a relatively high confidence that this page is the next link. | |
**/ | |
var topPage = null; | |
for(var page in possiblePages) { | |
if(possiblePages.hasOwnProperty(page)) { | |
if(possiblePages[page].score >= 50 && (!topPage || topPage.score < possiblePages[page].score)) { | |
topPage = possiblePages[page]; | |
} | |
} | |
} | |
if(topPage) { | |
var nextHref = topPage.href.replace(/\/$/,''); | |
dbg('NEXT PAGE IS ' + nextHref); | |
readability.parsedPages[nextHref] = true; | |
return nextHref; | |
} | |
else { | |
return null; | |
} | |
}, | |
/** | |
* Build a simple cross browser compatible XHR. | |
* | |
* TODO: This could likely be simplified beyond what we have here right now. There's still a bit of excess junk. | |
**/ | |
xhr: function () { | |
if (typeof XMLHttpRequest !== 'undefined' && (window.location.protocol !== 'file:' || !window.ActiveXObject)) { | |
return new XMLHttpRequest(); | |
} | |
else { | |
try { return new ActiveXObject('Msxml2.XMLHTTP.6.0'); } catch(sixerr) { } | |
try { return new ActiveXObject('Msxml2.XMLHTTP.3.0'); } catch(threrr) { } | |
try { return new ActiveXObject('Msxml2.XMLHTTP'); } catch(err) { } | |
} | |
return false; | |
}, | |
successfulRequest: function (request) { | |
return (request.status >= 200 && request.status < 300) || request.status === 304 || (request.status === 0 && request.responseText); | |
}, | |
ajax: function (url, options) { | |
var request = readability.xhr(); | |
function respondToReadyState(readyState) { | |
if (request.readyState === 4) { | |
if (readability.successfulRequest(request)) { | |
if (options.success) { options.success(request); } | |
} | |
else { | |
if (options.error) { options.error(request); } | |
} | |
} | |
} | |
if (typeof options === 'undefined') { options = {}; } | |
request.onreadystatechange = respondToReadyState; | |
request.open('get', url, true); | |
request.setRequestHeader('Accept', 'text/html'); | |
try { | |
request.send(options.postBody); | |
} | |
catch (e) { | |
if (options.error) { options.error(); } | |
} | |
return request; | |
}, | |
/** | |
* Make an AJAX request for each page and append it to the document. | |
**/ | |
curPageNum: 1, | |
appendNextPage: function (nextPageLink) { | |
readability.curPageNum+=1; | |
var articlePage = document.createElement("DIV"); | |
articlePage.id = 'readability-page-' + readability.curPageNum; | |
articlePage.className = 'page'; | |
articlePage.innerHTML = '<p class="page-separator" title="Page ' + readability.curPageNum + '">§</p>'; | |
document.getElementById("readability-content").appendChild(articlePage); | |
if(readability.curPageNum > readability.maxPages) { | |
var nextPageMarkup = "<div style='text-align: center'><a href='" + nextPageLink + "'>View Next Page</a></div>"; | |
articlePage.innerHTML = articlePage.innerHTML + nextPageMarkup; | |
return; | |
} | |
/** | |
* Now that we've built the article page DOM element, get the page content | |
* asynchronously and load the cleaned content into the div we created for it. | |
**/ | |
(function(pageUrl, thisPage) { | |
readability.ajax(pageUrl, { | |
success: function(r) { | |
/* First, check to see if we have a matching ETag in headers - if we do, this is a duplicate page. */ | |
var eTag = r.getResponseHeader('ETag'); | |
if(eTag) { | |
if(eTag in readability.pageETags) { | |
dbg("Exact duplicate page found via ETag. Aborting."); | |
articlePage.style.display = 'none'; | |
return; | |
} else { | |
readability.pageETags[eTag] = 1; | |
} | |
} | |
// TODO: this ends up doubling up page numbers on NYTimes articles. Need to generically parse those away. | |
var page = document.createElement("DIV"); | |
/** | |
* Do some preprocessing to our HTML to make it ready for appending. | |
* • Remove any script tags. Swap and reswap newlines with a unicode character because multiline regex doesn't work in javascript. | |
* • Turn any noscript tags into divs so that we can parse them. This allows us to find any next page links hidden via javascript. | |
* • Turn all double br's into p's - was handled by prepDocument in the original view. | |
* Maybe in the future abstract out prepDocument to work for both the original document and AJAX-added pages. | |
**/ | |
var responseHtml = r.responseText.replace(/\n/g,'\uffff').replace(/<script.*?>.*?<\/script>/gi, ''); | |
responseHtml = responseHtml.replace(/\n/g,'\uffff').replace(/<script.*?>.*?<\/script>/gi, ''); | |
responseHtml = responseHtml.replace(/\uffff/g,'\n').replace(/<(\/?)noscript/gi, '<$1div'); | |
responseHtml = responseHtml.replace(readability.regexps.replaceBrs, '</p><p>'); | |
responseHtml = responseHtml.replace(readability.regexps.replaceFonts, '<$1span>'); | |
page.innerHTML = responseHtml; | |
/** | |
* Reset all flags for the next page, as they will search through it and disable as necessary at the end of grabArticle. | |
**/ | |
readability.flags = 0x1 | 0x2 | 0x4; | |
var nextPageLink = readability.findNextPageLink(page), | |
content = readability.grabArticle(page); | |
if(!content) { | |
dbg("No content found in page to append. Aborting."); | |
return; | |
} | |
/** | |
* Anti-duplicate mechanism. Essentially, get the first paragraph of our new page. | |
* Compare it against all of the the previous document's we've gotten. If the previous | |
* document contains exactly the innerHTML of this first paragraph, it's probably a duplicate. | |
**/ | |
var firstP = content.getElementsByTagName("P").length ? content.getElementsByTagName("P")[0] : null; | |
if(firstP && firstP.innerHTML.length > 100) { | |
for(var i=1; i <= readability.curPageNum; i+=1) { | |
var rPage = document.getElementById('readability-page-' + i); | |
if(rPage && rPage.innerHTML.indexOf(firstP.innerHTML) !== -1) { | |
dbg('Duplicate of page ' + i + ' - skipping.'); | |
articlePage.style.display = 'none'; | |
readability.parsedPages[pageUrl] = true; | |
return; | |
} | |
} | |
} | |
readability.removeScripts(content); | |
thisPage.innerHTML = thisPage.innerHTML + content.innerHTML; | |
/** | |
* After the page has rendered, post process the content. This delay is necessary because, | |
* in webkit at least, offsetWidth is not set in time to determine image width. We have to | |
* wait a little bit for reflow to finish before we can fix floating images. | |
**/ | |
window.setTimeout( | |
function() { readability.postProcessContent(thisPage); }, | |
500 | |
); | |
if(nextPageLink) { | |
readability.appendNextPage(nextPageLink); | |
} | |
} | |
}); | |
}(nextPageLink, articlePage)); | |
}, | |
/** | |
* 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(!readability.flagIsActive(readability.FLAG_WEIGHT_CLASSES)) { | |
return 0; | |
} | |
var weight = 0; | |
/* Look for a special classname */ | |
if (typeof(e.className) === 'string' && e.className !== '') | |
{ | |
if(e.className.search(readability.regexps.negative) !== -1) { | |
weight -= 25; } | |
if(e.className.search(readability.regexps.positive) !== -1) { | |
weight += 25; } | |
} | |
/* Look for a special ID */ | |
if (typeof(e.id) === 'string' && e.id !== '') | |
{ | |
if(e.id.search(readability.regexps.negative) !== -1) { | |
weight -= 25; } | |
if(e.id.search(readability.regexps.positive) !== -1) { | |
weight += 25; } | |
} | |
return weight; | |
}, | |
nodeIsVisible: function (node) { | |
return (node.offsetWidth !== 0 || node.offsetHeight !== 0) && node.style.display.toLowerCase() !== 'none'; | |
}, | |
/** | |
* Remove extraneous break tags from a node. | |
* | |
* @param Element | |
* @return void | |
**/ | |
killBreaks: function (e) { | |
try { | |
e.innerHTML = e.innerHTML.replace(readability.regexps.killBreaks,'<br />'); | |
} | |
catch (eBreaks) { | |
dbg("KillBreaks failed - this is an IE bug. Ignoring.: " + eBreaks); | |
} | |
}, | |
/** | |
* 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 targetList = e.getElementsByTagName( tag ); | |
var isEmbed = (tag === 'object' || tag === 'embed'); | |
for (var y=targetList.length-1; y >= 0; y-=1) { | |
/* Allow youtube and vimeo videos through as people usually want to see those. */ | |
if(isEmbed) { | |
var attributeValues = ""; | |
for (var i=0, il=targetList[y].attributes.length; i < il; i+=1) { | |
attributeValues += targetList[y].attributes[i].value + '|'; | |
} | |
/* First, check the elements attributes to see if any of them contain youtube or vimeo */ | |
if (attributeValues.search(readability.regexps.videos) !== -1) { | |
continue; | |
} | |
/* Then check the elements inside this element for the same. */ | |
if (targetList[y].innerHTML.search(readability.regexps.videos) !== -1) { | |
continue; | |
} | |
} | |
targetList[y].parentNode.removeChild(targetList[y]); | |
} | |
}, | |
/** | |
* 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(!readability.flagIsActive(readability.FLAG_CLEAN_CONDITIONALLY)) { | |
return; | |
} | |
var tagsList = e.getElementsByTagName(tag); | |
var curTagsLength = tagsList.length; | |
/** | |
* 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. | |
**/ | |
for (var i=curTagsLength-1; i >= 0; i-=1) { | |
var weight = readability.getClassWeight(tagsList[i]); | |
var contentScore = (typeof tagsList[i].readability !== 'undefined') ? tagsList[i].readability.contentScore : 0; | |
dbg("Cleaning Conditionally " + tagsList[i] + " (" + tagsList[i].className + ":" + tagsList[i].id + ")" + ((typeof tagsList[i].readability !== 'undefined') ? (" with score " + tagsList[i].readability.contentScore) : '')); | |
if(weight+contentScore < 0) | |
{ | |
tagsList[i].parentNode.removeChild(tagsList[i]); | |
} | |
else if ( readability.getCharCount(tagsList[i],',') < 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 = tagsList[i].getElementsByTagName("p").length; | |
var img = tagsList[i].getElementsByTagName("img").length; | |
var li = tagsList[i].getElementsByTagName("li").length-100; | |
var input = tagsList[i].getElementsByTagName("input").length; | |
var embedCount = 0; | |
var embeds = tagsList[i].getElementsByTagName("embed"); | |
for(var ei=0,il=embeds.length; ei < il; ei+=1) { | |
if (embeds[ei].src.search(readability.regexps.videos) === -1) { | |
embedCount+=1; | |
} | |
} | |
var linkDensity = readability.getLinkDensity(tagsList[i]); | |
var contentLength = readability.getInnerText(tagsList[i]).length; | |
var toRemove = false; | |
if ( img > p ) { | |
toRemove = true; | |
} else if(li > p && tag !== "ul" && tag !== "ol") { | |
toRemove = true; | |
} else if( input > Math.floor(p/3) ) { | |
toRemove = true; | |
} else if(contentLength < 25 && (img === 0 || img > 2) ) { | |
toRemove = true; | |
} else if(weight < 25 && linkDensity > 0.2) { | |
toRemove = true; | |
} else if(weight >= 25 && linkDensity > 0.5) { | |
toRemove = true; | |
} else if((embedCount === 1 && contentLength < 75) || embedCount > 1) { | |
toRemove = true; | |
} | |
if(toRemove) { | |
tagsList[i].parentNode.removeChild(tagsList[i]); | |
} | |
} | |
} | |
}, | |
/** | |
* Clean out spurious headers from an Element. Checks things like classnames and link density. | |
* | |
* @param Element | |
* @return void | |
**/ | |
cleanHeaders: function (e) { | |
for (var headerIndex = 1; headerIndex < 3; headerIndex+=1) { | |
var headers = e.getElementsByTagName('h' + headerIndex); | |
for (var i=headers.length-1; i >=0; i-=1) { | |
if (readability.getClassWeight(headers[i]) < 0 || readability.getLinkDensity(headers[i]) > 0.33) { | |
headers[i].parentNode.removeChild(headers[i]); | |
} | |
} | |
} | |
}, | |
/*** Smooth scrolling logic ***/ | |
/** | |
* easeInOut animation algorithm - returns an integer that says how far to move at this point in the animation. | |
* Borrowed from jQuery's easing library. | |
* @return integer | |
**/ | |
easeInOut: function(start,end,totalSteps,actualStep) { | |
var delta = end - start; | |
if ((actualStep/=totalSteps/2) < 1) { | |
return delta/2*actualStep*actualStep + start; | |
} | |
actualStep -=1; | |
return -delta/2 * ((actualStep)*(actualStep-2) - 1) + start; | |
}, | |
/** | |
* Helper function to, in a cross compatible way, get or set the current scroll offset of the document. | |
* @return mixed integer on get, the result of window.scrollTo on set | |
**/ | |
scrollTop: function(scroll){ | |
var setScroll = typeof scroll !== 'undefined'; | |
if(setScroll) { | |
return window.scrollTo(0, scroll); | |
} | |
if(typeof window.pageYOffset !== 'undefined') { | |
return window.pageYOffset; | |
} | |
else if(document.documentElement.clientHeight) { | |
return document.documentElement.scrollTop; | |
} | |
else { | |
return document.body.scrollTop; | |
} | |
}, | |
/** | |
* scrollTo - Smooth scroll to the point of scrollEnd in the document. | |
* @return void | |
**/ | |
curScrollStep: 0, | |
scrollTo: function (scrollStart, scrollEnd, steps, interval) { | |
if( | |
(scrollStart < scrollEnd && readability.scrollTop() < scrollEnd) || | |
(scrollStart > scrollEnd && readability.scrollTop() > scrollEnd) | |
) { | |
readability.curScrollStep+=1; | |
if(readability.curScrollStep > steps) { | |
return; | |
} | |
var oldScrollTop = readability.scrollTop(); | |
readability.scrollTop(readability.easeInOut(scrollStart, scrollEnd, steps, readability.curScrollStep)); | |
// We're at the end of the window. | |
if(oldScrollTop === readability.scrollTop()) { | |
return; | |
} | |
window.setTimeout(function() { | |
readability.scrollTo(scrollStart, scrollEnd, steps, interval); | |
}, interval); | |
} | |
}, | |
/** | |
* Show the email popup. | |
* | |
* @return void | |
**/ | |
emailBox: function () { | |
var emailContainerExists = document.getElementById('email-container'); | |
if(null !== emailContainerExists) | |
{ | |
return; | |
} | |
var emailContainer = document.createElement("DIV"); | |
emailContainer.setAttribute('id', 'email-container'); | |
emailContainer.innerHTML = '<iframe src="'+readability.emailSrc + '?pageUrl='+encodeURIComponent(window.location)+'&pageTitle='+encodeURIComponent(document.title)+'" scrolling="no" onload="readability.removeFrame()" style="width:500px; height: 490px; border: 0;"></iframe>'; | |
document.body.appendChild(emailContainer); | |
}, | |
/** | |
* Close the email popup. This is a hacktackular way to check if we're in a "close loop". | |
* Since we don't have crossdomain access to the frame, we can only know when it has | |
* loaded again. If it's loaded over 3 times, we know to close the frame. | |
* | |
* @return void | |
**/ | |
removeFrame: function () { | |
readability.iframeLoads+=1; | |
if (readability.iframeLoads > 3) | |
{ | |
var emailContainer = document.getElementById('email-container'); | |
if (null !== emailContainer) { | |
emailContainer.parentNode.removeChild(emailContainer); | |
} | |
readability.iframeLoads = 0; | |
} | |
}, | |
htmlspecialchars: function (s) { | |
if (typeof(s) === "string") { | |
s = s.replace(/&/g, "&"); | |
s = s.replace(/"/g, """); | |
s = s.replace(/'/g, "'"); | |
s = s.replace(/</g, "<"); | |
s = s.replace(/>/g, ">"); | |
} | |
return s; | |
}, | |
flagIsActive: function(flag) { | |
return (readability.flags & flag) > 0; | |
}, | |
addFlag: function(flag) { | |
readability.flags = readability.flags | flag; | |
}, | |
removeFlag: function(flag) { | |
readability.flags = readability.flags & ~flag; | |
} | |
}; | |
readability.init(); |
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