713 posts tagged “javascript”
2009
OCR and Neural Nets in JavaScript. John dissects the brilliant Greasemonkey script that solves simple captchas using the canvas element and HTML5’s getImageData API.
google-mobwrite. Neil Fraser’s terrifyingly clever differential synchronization algorithm (for SubEthaEdit-style collaboration over the web) is now available as an open source Python and JavaScript library.
AJAX APIs Playground. Ferociously useful collection of executable and editable example code for all(?) of Google’s JavaScript APIs, including Google Maps and the increasingly interesting Visualization API.
jQuery 1.3.1 Released. Bug fix for 1.3, mainly browser compatibility issues. Of interest: jQuery no longer ship a packed version (where JS is used to further decompress a string), as their tests show that this reduces performance due to the overhead of the extra decompression. They still provide a YUI Compressor minified version.
jQuery 1.3 and the jQuery Foundation. The IP for jQuery and jQuery UI now rests with the Software Freedom Conservancy (a smart alternative to setting up a brand new foundation), while Sizzle is a separate project looked after by the Dojo Foundation.
Sloppy—the slow proxy. Java Web Start GUI application which runs a proxy to the site of your choice simulating lower connection speeds—great for testing how well your ajax holds up under poor network conditions.
Visualising Radio, pushing, not pulling. The BBC’s new radio player uses Comet over a Flash XMLsocket connection transport, with an ActiveMQ message queue behind the scenes. I’d like to know what server they’re using to broadcast out to the XMLsocket connections.
A Snapshot of The Yahoo! Photos Beta (from 2006). Scott Schiller shares an internal retrospective on the Yahoo! Photos interface from 2006, which was years ahead of its time (they started building it before the term Ajax had even been coined). The material on memory management and event delegation is particularly interesting.
instanceof considered harmful (or how to write a robust isArray. JavaScript’s instanceof operator breaks when dealing with objects that may have been created in a different document or frame, since constructors are unique to each frame. Instead, you can check for arrays using the default Object.toString method which the JS spec guarantees will return [object Array].
Manage Amazon EC2 With New Web-Based AWS Management Console. Finally! I’m amazed it took Amazon so long to do this. Managing EC2 instances from a custom Firefox extension was pretty bizarre. It’s a very nice interface, built on top of YUI. Unfortunately you still have to manage your entire virtual server farm using a single shared Amazon account.
2008
ReferenceError: console is not defined. Since Firebug 1.2 you need to call window.loadFirebugConsole() in order for console.log and friends to work.
Quickchoice—a Speed Dial clone
(via)
Lovely demonstration of the CSS transform property, as supported by modern browsers. The magic is all in the iframe { transform: scale(0.25, 0.25) translate(-1200px, -900px) }
jQuery: Changeset 5990. “Added a new liveQuery/event delegation hybrid method”. Lets you add events that continue to work as new elements are dynamically appended to the DOM, e.g. $(’div p.foo’).live(’click’, fn). Works by adding an event handler to the root document element itself and relying on event bubbling. I have to admit I preferred the earlier proposal of $(’div’).delegate(’p.foo’..), which feels like it should have much better performance—anyone know of a good plugin that supports this?
jQuery changeset 5985 (via) jQuery trunk has ditched browser sniffing in favour of feature testing, where a small suite of unit-test-like code blocks is used to detect whether a browser supports specific idioms. If the tests fail jQuery still makes assumptions about what the fix is, but it’s not hard to imagine the library eventually using code tests to ensure the fix will work as well.
Someone asked for onbeforeunload, so I started fixing it. Then I found that there was some rot in the drywall. So I took down the drywall. Then I found a rat infestation. So I killed all the rats. Then I found that the reason for the rot was a slow leak in the plumbing. So I tried fixing the plumbing, but it turned out the whole building used lead pipes. So I had to redo all the plumbing. But then I found that the town's water system wasn't quite compatible with modern plumbing techniques, and I had to dig up the entire town. And that's basically it.
Integrating Facebook Connect with Django in 15 minutes. Django authentication middleware that calls the Facebook REST API using a cookie set by Facebook Connect and checks if that person is your Facebook friend. Despite most of the magic happening on the server you still need Facebook’s JavaScript to set that cookie in the first place.
husk.org. a flickr machine tag browser (via) Flickr recently added API methods for exploring the machine tags used by the community. Paul Mison has built a neat OS X Finder style interface for exploring them, using JSONP and jQuery.
Visual Event. External code loading bookmarklet that visualises the JavaScript events hooked up to the current page, and lets you view the source code of the event handling function for each one. Only works for events added by jQuery, YUI or MooTools since those libraries maintain a cache of event handlers that they add, to work around the standard DOM’s omission of handler introspection.
Internet explorer mystery #1376. IE executes function definitions inside an “if (0)” block. That frightens me.
lightningtimer.net. I'm fed up of having to dig out or knock up a timer script every time I manage lightning talks, so I've given one a domain name. You can use lightningtimer.net/#90 to set a different start time for the counter.
Update March 25th 2025: I rescued an old copy of this from the Internet Archive and re-published it to tools.simonwillison.net/lightning-timer.
Introducing Acre. I’m losing track of all the server-side JavaScript hosted web application platforms now. Here’s the Freebase contribution to the genre, complete with IDE, templating language and strong integration with Freebase itself.
jQuery history plugin. I used this plugin to add back button support to a small Ajax app today, with great results. I tried it a while ago and it didn’t work in Safari, but someone has updated it since and now it works perfectly.
Yahoo, Caja, OpenSocial. Yahoo!’s new application platform uses OpenSocial, and protects itself from malicious JavaScript using Google’s Caja secure JavaScript engine. I hadn’t realised that Caja was ready for production use—this is excellent news.
JSSpeccy. A ZX Spectrum emulator written in Javascript.
I'm really typecasting myself here. If there were an international "Person most likely to write a Spectrum emulator in Javascript" award, I'd have taken it for the last five years running.
typeface.js. Outstanding hack—renders custom fonts using VML in IE and canvas in everything else, using fonts that are defined as a set of vector paths stored using JSON.
Freebase Hack Day. I’m finding Freebase increasingly interesting at the moment, and their public hack day on the 8th November in San Francisco looks like it could be a lot of fun. They’ll be previewing Acre, a new server-side JavaScript application platform targeted at building Freebase powered applications. Hit “view source” at the bottom of the hack day site to see what an Acre app looks like.
CSSHttpRequest (via) Devious cross-domain Ajax hack that uses CSS for transport (@import rules with data URIs, but it still works in IE). Similar to JSONP but safer, since JSONP can cause arbitrary JavaScript to execute.
FriendFeed launch a real-time API. This is huge: JSONP plus long polling Comet, with “everything since X” tokens to ensure you don’t miss anything. This is the first open Comet API I’ve seen anywhere. Combine this with FriendFeed’s regular API (which allows arbitrary message posting) and you’ve got a really powerful tool for hackers who want to experiment with Comet without rigging up their own infrastructure.
Private Messages with cometD Chat. cometd-java (a Java servlet reference implementation of the Bayeux protocol) can be extended with BayeuxService subclasses that run within the server itself.