Google Closure: How not to write JavaScript At the Edge of the Web conference in Perth last week I got to catch up with Dmitry Baranovskiy, the creator of the Raphaël and gRaphaël JavaScript libraries. Perhaps the most important thing these libraries do is make sophisticated vector graphics possible in Internet Explorer, where JavaScript performance is relatively poor. Dmitry, therefore, has little patience for poorly-written JavaScript like the code he found in Google’s just-released Closure Library. Having delivered a talk on how to write your own JavaScript library (detailed notes) at the conference, Dmitry shared his thoughts on the new library over breakfast the next morning. “Just what the world needs—another sucky JavaScript library,” he said. For the rest of the day, to anyone who would listen, Dmitry cited example after example of the terrible code he had found when he went digging through Closure. “I’ll make you a deal,” I told him. The Slow Loop From array.js, line 63: for (var i = fromIndex; i < arr.length; i++) {
JavaScript Tutorial JsMini.com - Minify Your Javascript/jQuery Code Online A JavaScript Module Pattern Eric Miraglia (@miraglia) is an engineering manager for the YUI project at Yahoo. Eric has been at Yahoo since 2003, working on projects ranging from Yahoo Sports to YUI. For the past several years, Eric and his colleagues on the YUI team have worked to establish YUI as the foundation for Yahoo’s frontend engineering work while open-sourcing the project and sharing it with the world under a liberal BSD license. Eric is an editor and frequent contributor to YUIBlog; his personal blog is at ericmiraglia.com. Prior to working at Yahoo, Eric taught writing at Stanford and elsewhere and led frontend engineering teams at several startups. Global variables are evil. Douglas Crockford has been teaching a useful singleton pattern for achieving this discipline, and I thought his pattern might be of interest to those of you building on top of YUI. 1. YAHOO.namespace("myProject"); This assigns an empty object myProject as a member of YAHOO (but doesn’t overwrite myProject if it already exists). 2.
Tomek on Software: Multi-line strings in JavaScript and Node.js When writing Node.js or JavaScript applications, you sometimes need to embed multi-line strings in your code. It may be a snippet of HTML, a fragment of textual template, a piece of XML (remember XML?), or code in another programming language. JavaScript has no built-in way of representing multi-line strings. var html = (function () {/* <! What happens here? That pattern can be applied to a variety of types of multi-line text. Enjoy! css3-mediaqueries-js - Project Hosting on Google Code css3-mediaqueries.js by Wouter van der Graaf is a JavaScript library to make IE 5+, Firefox 1+ and Safari 2 transparently parse, test and apply CSS3 Media Queries. Firefox 3.5+, Opera 7+, Safari 3+ and Chrome already offer native support. UPDATE: Google discontinued the downloads section. Download newest version 1.0 from here: Usage: just include the script in your pages. (And you should combine and compress with other scripts and include it just before </body> for better page speed - but you already knew that). Write your media queries like you would for browsers with native support. Note: Doesn't work on @import'ed stylesheets (which you shouldn't use anyway for performance reasons). Happy media querying!
JavascriptTips - jslibs - JavaScript language advanced tips and tricks - standalone JavaScript development runtime environment with general purpose native libraries These tips and tricks are not related to any web browser or any Document Object Model (DOM), they are only general purpose tips and tricks for the JavaScript language. Some of these tricks are using a latest version of JavaScript language (v1.8) and cannot run with the Microsoft Implementation of JavaScript (v1.5). All these tricks has been tested with the Mozilla SpiderMonkey/TraceMonkey JavaScript engine (v1.8). You can try these examples using jshost, a command-line JavaScript interpreter. If you need more explanation about one of the following tips, don't hesitate to ask me or use the comment section at the end of this page. See the TOC at the end of the page. Append an array to another array var a = [4,5,6];var b = [7,8,9];Array.prototype.push.apply(a, b); uneval(a); // is: [4, 5, 6, 7, 8, 9] Milliseconds since epoch +new Date() // 1259359833574 Simulate threads using yield operator JavaScript 1.7 //// thread definitionfunction Thread( name ) { for ( var i = 0; i < 5; i++ ) { prints: note output:
Understanding JavaScript’s this keyword | JavaScript, JavaScript (In Portugese) The JavaScript this keyword is ubiquitous yet misconceptions abound. What you need to know Every execution context has an associated ThisBinding whose lifespan is equal to that of the execution context and whose value is constant. There are three types of execution context: global, function and evaluation. Here’s a tabular summary followed by a little more detail, and some examples: 1. 2. a) Invoke as a methodthis is the baseValue of the property reference b) Invoke as baseless function callthis is the global object (or undefined in strict mode) The same applies to self invoking functions: c) Invoke using Function.prototype.callthisis passed by argument d) Invoke using Function.prototype.applythis is passed by argument e) Invoke a constructor using newthis is the newly created object 3. What you might want to know This section explores the process by which this gets its value in the functional context – using ECMA-262 version 5.1 as a reference. from ECMA 5.1, 11.1.1 1. 1. In full…
JavaScript JavaScript (JS) is a lightweight interpreted (or just-in-time compiled) programming language with first-class functions. While it is most well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat. JavaScript is a prototype-based, multi-paradigm, single-threaded, dynamic language, supporting object-oriented, imperative, and declarative (e.g. functional programming) styles. JavaScript's dynamic capabilities include runtime object construction, variable parameter lists, function variables, dynamic script creation (via eval), object introspection (via for...in and Object utilities), and source-code recovery (JavaScript functions store their source text and can be retrieved through toString()). This section is dedicated to the JavaScript language itself, and not the parts that are specific to Web pages or other host environments. Looking to become a front-end web developer? Get started
base2 - Project Hosting on Google Code Because this library is standards-based it means that you don’t have to learn a new API. It uses standard (DOM, ECMAScript) properties and methods throughout which also means that there is no need for a lot of accompanying documentation. base2 is a lightweight library that irons out all the annoying differences in JavaScript implementations. It provides the additional functionality from JavaScript 1.6+ that only Mozilla browsers implement. It also adds some features from ES4. A fast implementation of the Selectors API Fixes broken browser implementations of the DOM events module including document.createEvent(), dispatchEvent(), addEventListener(), etc Supports DOMContentLoaded Fixes getAttribute()/setAttribute()/hasAttribute() (Internet Explorer) Implements getElementsByClassName() Implements a few other useful DOM methods like getComputedStyle() and compareDocumentPosition() Supports a variety of browsers including ancient browsers like IE5.0 (Windows and Mac) Current version: 1.0.2
Sylvester - Vector and Matrix math for JavaScript Badass JavaScript evercookie - virtually irrevocable persistent cookies samy's home page || follow my twitter || email me || samy kamkar October 11, 2010: Reported on the front page of the New York Times Find the latest details, code, and implementations on github @ Cookie found: uid = currently not set Click to create an evercookie. Don't worry, the cookie is a random number between 1 and 1000, not enough for me to track you, just enough to test evercookies. Now, try deleting this "uid" cookie anywhere possible, then or evercookie is written in JavaScript and contains portions in Java, SWF/ActionScript (Flash) and C# (Silverlight). What is the point of evercookie? csshack, best website ever See CONTACT. Questions or comments, email me: code@samy.pl.