The CodeThis user script runs on all pages. It is quite complex, but it breaks down into five steps: - Define useful variables
The first section defines several variables, including various versions of the Wikipedia icons to label the new links, regular expressions to identify possible terms, and the URLs for the keyword lookup service and for Wikipedia itself. - Define convenience functions
The addWikiLinkStyle function adds new global style information to the page so that the Wikipedia links change appearance when the mouse moves over them. The getTerms function retrieves all the possible terms from the page that match a given regular expression. - Call the keyword lookup service
The main part of the script uses three separate regular expressions to extract candidates for linking. (The third expression is for acronyms.) It then calls the web service using GM_xmlhttpRequest. The keyword lookup service works with GET or POST; we use the POST method because the list of candidate terms might be too long to fit in the URL of a GET request. - Add hyperlinks to the text
The web service request is performed asynchronously, so nothing happens until the server returns some results. The GM_xmlhttpRequest calls our onload callback function, which parses the XML returned from the keyword lookup service to get the terms that match the Wikipedia database. We use the matching terms to construct a regular expression, and then we iterate over all the text nodes in the HTML page and wrap each matched term with a link to the corresponding Wikipedia page. - Provide undo capability
Finally, we add a menu item to the Firefox menu bar, using GM_ registerMenuCommand, which removes the Wikipedia links we just added.
To minimize the load on Stefan's keyword lookup service, we use an associative array, usedTerms, to keep track of which term candidates have been found on the page. This saves time and bandwidth by ensuring that each potential keyword is checked only once. Save the following user script as wikipedia-proxy.user.js:
// ==UserScript==
// @name Wikiproxy: Greasemonkey Edition
// @namespace http://www.allpeers.com/blog/greasemonkey
// @description Adds Wikipedia links to key terms in webpages
// @include http://*
// @exclude http://wikiproxy.whitelabel.org/*
// @exclude http://www.theyworkforyou.com/*
// @exclude http://*.wikipedia.tld/*
// ==/UserScript==
// based on code by Matthew Gertner, Valentin Laube, and others
// and included here with their gracious permission
var iconcolor = 0; // 0 blue, 1 green, 2 red
var icons = [
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKAgMAAADwXCcu"+
"AAAADFBMVEUWJgGkyP%2F%2F%2F%2F8AZv87Gt1vAAAAAXRSTlMAQObYZgAAAC1JRE"+
"FUCNdjYP7%2FgYF51QYG%2Fv8bGHhXb2BgXg2hzco%2FMNw8z8BgzsDAwMPAAAAtcQ"+
"zEPgrvTwAAAABJRU5ErkJggg%3D%3D",
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKAgMAAADwXCcu"+
"AAAADFBMVEUbHgGW0nL%2F%2F%2F9SqxuFak3hAAAAAXRSTlMAQObYZgAAAC1JREFU"+
"CNdjYP7%2FgYF51QYG%2Fv8bGHhXb2BgXg2hzco%2FMNw8z8BgzsDAwMPAAAAtcQzE"+
"PgrvTwAAAABJRU5ErkJggg%3D%3D",
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKAgMAAADwXCcu"+
"AAAADFBMVEUbHgH%2Fq47%2F%2F%2F%2F%2FVBnJ4fJlAAAAAXRSTlMAQObYZgAAAC"+
"1JREFUCNdjYP7%2FgYF51QYG%2Fv8bGHhXb2BgXg2hzco%2FMNw8z8BgzsDAwMPAAA"+
"AtcQzEPgrvTwAAAABJRU5ErkJggg%3D%3D"
];
var icons2 = [
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs%2"+
"B9AAAAeElEQVQY02NkQAIB0%2F7%2FZ8ABWNAF1mdiKgqczsDASMi09ZkQhSgmFjoz"+
"MNipoZoEA0wwxoYsRsb%2BvQw4AROy1YXOuBUyIyuyU2NgOHSLgaFgFQODFD8Dw4n7"+
"DAwrzyCZdPDm%2F%2F%2F%2F%2F0NomKcCpiHYKOGHrAgvIKQIAECSPtEmaizfAAAA"+
"AElFTkSuQmCC",
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs%2"+
"B9AAAAi0lEQVQY02NkQAIdR5P%2FM%2BAALOgC5VZzMBR1HkthYCRkWrnVHIbOYymo"+
"JupLWzN4yCeimAQDTDBGhfVcxotPj%2BJyIkJhx9Hk%2F%2FrS1jgVMiIr8pBPZNjx"+
"cD7DxadHGfSlrRlQbOg4mvx%2F%2B4N5%2F%2F%2F%2F%2F%2F9%2F%2B4N5%2F2Ge"+
"6jia%2FB%2FDgzDF%2BMKRqMBmYGBgAAApFkF%2BHyXzbAAAAABJRU5ErkJggg%3D%"+
"3D",
"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs%2"+
"B9AAAAf0lEQVQY042QyxGCQBBE36BRQQ4UKSw5QA4sOeDVo5gDxOCdQNqDfN1asS8z"+
"NfWqa7qNneSdiOgaXKoupNoSO3WrOmjLL8esgDQ%2FOC1KlsXqmzE8Yi9uoLwTWREF"+
"LwcozWF8wr0BM5heMPabk4Zekj5zDiXvFARc4R89%2FlU2wBsinj50jQNjuAAAAABJ"+
"RU5ErkJggg%3D%3D"
];
var bgprefix = "url("
var bgsuffix = ") center right no-repeat";
var requestUrl = "http://wikiproxy.whitelabel.org/xml.php";
var wikipediaUrlPrefix = "http://en.wikipedia.org/wiki/";
var excludeAncestors = ["a", "script", "style", "input",
"textarea", "select", "option"];
var excludeXPath = "ancestor::*[";
for (var tagNum=0; tagNum<excludeAncestors.length; tagNum++)
excludeXPath += (tagNum == 0 ? "" : " or ") + "self::" +
excludeAncestors[tagNum];
excludeXPath += "]";
// Regular expression definitions from News Wikiproxy
var capsword = "A|[A-Z][a-zA-Z'0-9]{1,}";
var fillerwords = "a|of|and|in|on|under|the";
var middlewordre = "(" + capsword + "|" + fillerwords + "|[A-Z]\.)[ \\t]*";
var endwordre = "(" + capsword + ")[ \\t]*";
var acronymre = "\\b([A-Z][A-Z0-9]{2,})\\b";
// Match either "Two Endwords" or "Endword and Some Middle Words"
var greedyproperre = "\\b(" + endwordre + "(" + middlewordre + ")*" +
endwordre + ")\\b";
// Match without filler words (so if you have a phrase like
// "Amnesty International and Human Rights Watch" you also get both parts
// separately "Amnesty International" and "Human Rights Watch")
var frugalproperre = "\\b((" + endwordre + "){2,})\\b";
var usedTerms = new Object();
function addWikiLinkStyle() {
var wikiLinkStyle = document.createElement('style');
wikiLinkStyle.id = "wikilinkstyle";
wikiLinkStyle.type = "text/css";
wikiLinkStyle.innerHTML = '.wikilink, .wikilink_over {\n'
+ 'color: inherit;\n'
+ 'padding-right: 13px;\n'
+ '}\n'
+ '.wikilink {\n'
+ 'background: transparent ' + bgprefix
+ icons[iconcolor] + bgsuffix + ';\n'
+ '}\n'
+ '.wikilink_over {\n'
+ 'background: transparent ' + bgprefix
+ icons2[iconcolor] + bgsuffix + ';\n'
+ '}';
document.getElementsByTagName('head')[0].appendChild(wikiLinkStyle);
}
function getTerms(str, regexpstr, terms) {
var candidates = str.match(new RegExp(regexpstr, "mg"));
for (var i=0; i<candidates.length; i++) {
var term = candidates[i];
while (term.charAt(term.length-1) == " ")
term = term.substring(0, term.length-1);
if (usedTerms[term] == null) {
if (terms.length > 0) {
terms += " ";
}
terms += term.replace(/ /g, "_");
usedTerms[term] = term;
}
}
return terms;
}
if (document.documentElement.tagName == "HTML") {
var treeWalker = document.createTreeWalker(
document.documentElement, NodeFilter.SHOW_TEXT, null, false);
var text = "";
var textNode;
while (textNode = treeWalker.nextNode()) {
if (!document.evaluate("ancestor::script", textNode, null,
XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue) {
text += textNode.nodeValue + "\n";
}
}
var terms = getTerms(text, greedyproperre, "");
terms = getTerms(text, frugalproperre, terms);
terms = getTerms(text, acronymre, terms);
GM_xmlhttpRequest({
method: 'POST',
url: requestUrl,
headers: {
'User-agent': 'Mozilla/4.0 (compatible) Greasemonkey',
'Content-type': 'application/x-www-form-urlencoded'
},
data: 'text=' + escape(terms),
onload: function(responseDetails) {
var parser = new DOMParser();
var responseXML = parser.parseFromString(
responseDetails.responseText, "text/xml");
var termSnapshot = document.evaluate("/wikiproxy/term/text()",
responseXML, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
null);
var normalizedTerms = new Object();
var termRegExp = "";
for (var i=0; i<termSnapshot.snapshotLength; i++)
{
var termNodeValue = termSnapshot.snapshotItem(i).
nodeValue.replace(/_/g, " ");
normalizedTerms[termNodeValue.toLowerCase()] =
termNodeValue;
if (termRegExp.length > 0) {
termRegExp += "|";
}
termRegExp += termNodeValue;
}
termRegExp = new RegExp("\\b(" + termRegExp + ")\\b", "mg");
treeWalker = document.createTreeWalker(
document.documentElement, NodeFilter.SHOW_TEXT, null,
false);
while (textNode = treeWalker.nextNode())
{
if (responseXML.evaluate(excludeXPath, textNode, null,
XPathResult.FIRST_ORDERED_NODE_TYPE,
null).singleNodeValue) { continue; }
var matches = textNode.nodeValue.match(termRegExp);
if (!matches) { continue; }
// add wiki link style
if (!document.getElementById ('wikilinkstyle')) {
addWikiLinkStyle();
}
for (i=0; i<matches.length; i++)
{
var term = matches[i];
if(!term)continue;
var displayTerm = term.replace(/_/g, " ");
term = normalizedTerms[term.toLowerCase()];
var termIndex = textNode.nodeValue.indexOf(displayTerm);
var preTermNode = document.createTextNode(
textNode.nodeValue.substring(0, termIndex));
textNode.nodeValue = textNode.nodeValue.substring(
termIndex+displayTerm.length);
var anchor = document.createElement("a");
anchor.className = "wikilink";
anchor.addEventListener('mousemove', function () {
this.className = 'wikilink_over';
}, true);
anchor.addEventListener('mouseout', function () {
this.className = 'wikilink';
}, true);
anchor.href = wikipediaUrlPrefix + term;
var termNode = document.createTextNode(displayTerm);
anchor.insertBefore(termNode, anchor.firstChild);
textNode.parentNode.insertBefore(preTermNode, textNode);
textNode.parentNode.insertBefore(anchor, textNode);
}
}
}
});
}
function undoWikify() {
var wlinks = document.evaluate('//a[@class="wikilink"]',
document, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
for (var i = 0; i < wlinks.snapshotLength; i++) {
var wlink = wlinks.snapshotItem(i);
var text = document.createTextNode(wlink.textContent);
wlink.parentNode.replaceChild(text, wlink);
}
}
GM_registerMenuCommand('Undo Wikify', undoWikify);
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