Simon Willison’s Weblog

Blogmarks tagged javascript in Jan

Filters: Type: blogmark × Month: Jan × javascript ×


Making GitHub’s new homepage fast and performant. A couple of really clever tricks in this article by Tobias Ahlin. The first is using IntersectionObserver in conjunction with the video preload=“none” attribute to lazily load a video when it scrolls into view. The second is an ingenious trick to create an efficiently encoded transparent JPEG image: embed the image in a SVG file twice, once as the image and once as a transparency mask. # 29th January 2021, 7:05 pm

hooks-in-a-nutshell.js (via) Neat, heavily annotated implementation of React-style hooks in pure JavaScript, really useful for understanding how they work. # 4th January 2021, 6:36 pm

2020 Web Milestones (via) A lot of stuff is happening in 2020! Mike Sherov rounds it up—highlights include the release of Chromium Edge (Microsoft’s Chrome-powered browser for Windows 7+), Web Components supported in every major browser, Deno 1.x, SameSite Cookies turned on by default (which should dramatically reduce CSRF exposure) and Python 2 and Flash EOLs. # 24th January 2020, 4:43 am

Snowpack (via) Really interesting new twist on build systems for JavaScript. Modern browsers (everything since IE11) support JavaScript modules, but actually working with them is tricky since so much of the JavaScript ecosystem expects you to be using a bundler like Webpack. Snowpack is a tool for converting npm dependencies into JavaScript modules which can then be loaded directly by the browser, taking advantage of HTTP/2 to efficiently load the resulting larger number of files. # 10th January 2020, 5:06 am

Observable: An Earthquake Globe in Ten Minutes. Well worth your time. Jeremy Ashkenas uses Observable to live-code an interactive visualization of recent earthquakes around the world, using USGS data (fetched as JSON), d3, topoJSON and an Observable notebook. I’m sold—this is truly ground-breaking new technology. # 31st January 2018, 5:01 pm

Observable Beta (via) Observable just released their beta, and it’s quite something. It’s by Mike Bostock (d3), Jeremy Ashkenas (Backbone, CoffeeScript) and Tom MacWright (Mapbox Studio). The easiest way to describe it is Jupyter notebooks for JavaScript supporting reactive programming—so code is evaluated as you type and you can add interactive widgets (like sliders and canvas views) to construct explorable visualizations on the fly. # 31st January 2018, 4:46 pm

The code injected to steal passwords in Tunisia. Here’s the JavaScript that (presumably) the Tunisian government were injecting in to login pages that were served over HTTP. # 24th January 2011, 6:45 pm

Display your events on your own website with Lanyrd Badges. We’ve launched badges for Lanyrd—JavaScript that lets you embed a top bar or a content “splat” showing events you plan to attend, talks you’ve given in the past and other various combinations. I’m quite pleased with the implementation—the badges are configured using classes on a link to your Lanyrd profile, and the badges themselves are served through a combination of Amazon CloudFront for the initial script and a Varnish cache for the badge data itself to keep things nice and snappy. # 13th January 2011, 8:38 pm

Hot Code Loading in Node.js. Blaine Cook’s patch for Node.js that enables Erlang-style hot code loading, so you can switch out your application logic without restarting the server or affecting existing requests. This could make deploying new versions of Node applications trivial. I’d love to see a Node hosting service that allows you to simply upload a script file and have it execute on the Web. # 31st January 2010, 1:57 pm

Dojo 1.4.1 vs jQuery 1.4.2pre on Taskspeed. John Resig’s reponse. When JavaScript libraries compete on performance, everybody wins. # 29th January 2010, 2:19 pm

Dojo: Still Twice As Fast When It Matters Most. Alex Russell shows how Dojo out-performs jQuery on the TaskSpeed benchmark, which attempts to represent common tasks in real-world applications and has had code that have been optimised by the development teams behind each of the libraries. # 28th January 2010, 10:40 pm

jQuery 1.4 Released. With comprehensive release notes. Huge performance improvements and a ton of very sensible enhancements to the API—far too many to summarise. # 14th January 2010, 10:37 pm

Ehy IE8, I Can Has Some Clickjacking Protection? (via) IE8 has built-in protection against clickjacking, but it’s opt-in (with a custom HTTP header) and IE only. It turns out the usual defence against clickjacking (using framebusting JavaScript) doesn’t work in IE as it can be worked around with a security=“restricted” attribute on an iframe. # 29th January 2009, 1:39 pm

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. # 25th January 2009, 12 am

google-mobwrite. Neal 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. # 24th January 2009, 11:55 pm

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. # 22nd January 2009, 6:38 pm

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. # 22nd January 2009, 10:41 am

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. # 14th January 2009, 5:59 pm

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. # 13th January 2009, 4:17 pm

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. # 13th January 2009, 12:59 am

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. # 12th January 2009, 10:21 pm

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]. # 12th January 2009, 10:55 am

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. # 9th January 2009, 9:34 am

Blob Sallad—canvas tag and JavaScript physics simulation experiment. Björn Lindberg provides a detailed code walkthrough of his brilliant canvas demo, inspired by Loco Rocco. # 26th January 2008, 12:25 pm

jQuery.ScrollTo (via) Neat jQuery plugin for animated scrolling of both windows and overflow elements. # 21st January 2008, 9:53 pm

Dangers of remote Javascript. Perl.com got hit by a JavaScript porn redirect when the domain of one of their advertisers expired and was bought by a porn company. Nat Torkington suggests keeping track of the expiration dates on any third party domains that are serving JavaScript on your site. # 20th January 2008, 9:49 am

Automate firing of onload events. Paul Irish suggests setting up your site’s onload handlers in a single external JavaScript file then executing different handlers depending on the body element’s id attribute. # 17th January 2008, 4:08 pm

.first() and .last() methods for jQuery. I got fed up of expecting these to exist, so I wrote them as a couple of one-liner plugins. # 16th January 2008, 9:41 pm

jQuery 1.2.2: 2nd Birthday Present. The API stays the same, but there are some healthy speed improvements, a new way of adding custom events and (most importantly) .ready() now waits for the CSS to be ready in addition to the DOM. # 15th January 2008, 8:59 am

Javascript CSS Selector Engine Timeline. It’s not every day you see a piece of code you wrote compared to a Ford Pinto :) # 14th January 2008, 1:25 pm