Simon Willison’s Weblog

Items tagged javascript in Nov

Filters: Month: Nov × javascript ×

BigInt: arbitrary-precision integers in JavaScript (via) The BigInt specification is now supported in Chrome—but it hasn’t yet made it to other browsers. The Chrome team have a really interesting solution: they’ve released a JSBI library which you can use to do BigInt calculations in any browser today, and an accompanying Babel plugin which can rewrite calls to that library into BigInt syntax once browser support catches up. I’ve never seen a library that includes a tool for refactoring itself into oblivion before. # 28th November 2018, 2:22 am

A Netflix Web Performance Case Study (via) Fascinating description of how Netflix knocked the 3G loading times of their homepage in half for logged-out users by rendering the React templates on the server-side and using the bare amount of vanilla JavaScript necessary to get the homepage interactive—then XHR prefetching the full React code needed to power the subsequent signup flow. Via Alex Russell, who tweets “I’m increasingly optimistic that we can cap JS emissions by quarantining legacy frameworks to the server side.” # 6th November 2018, 8:54 pm

Svelte RFC 0001: Reactive assignments (via) Svelte is a really interesting JavaScript framework: it offers a similar component-based developer experience to React but does it while delivering a tiny amount of code-to-the-browser thanks to being built entirely around a compiler that generates the minimum code necessary. In this RFC the Svelte team propose taking this approach even further, by generating code to accompany every relevant variable assignment that can trigger the corresponding view update. The document also has a very clear explanation of how React, Vue and current Svelte differ in their solutions to the challenge of updating the visible HTML view when the corresponding state changes. # 3rd November 2018, 4:58 pm

Object models (via) Extremely comprehensive and readable discussion of the object models of Python, JavaScript, Lua and Perl 5. I learned something new about every one of those languages. # 29th November 2017, 2:59 pm

Firefox Debugger Playground. Excellent hands-on tutorial to using the Firefox JavaScript debugger. I learned a bunch of neat tricks from this—including using conditional breakpoints to add temporary console.log statements—since that function returns undefined it won’t pause your code, but this saves you from having to remember to remove the lines from your source code later. I also didn’t know that the Firefox debugger can show the value of variables in paused code if you hover over them in the source pane. [UPDATE: Turns out Chrome DevTools do this as well—TIL] # 28th November 2017, 4:01 pm

VoxelSpace (via) Lovely clear explanation of the voxel space landscape rendering technique used by NovaLogic for Comanche back in 1992, including a working JavaScript demo plus pseudo-code in Python. # 24th November 2017, 7:30 pm

JOY.js (via) Delightful new exploratory programming environment from Nicky Case. Try the Turtle demo, which takes Logo and updates it for the modern web. # 21st November 2017, 2:50 pm

Porting Flickr to YUI 3: Lessons in Performance (at YUIConf 2010). Some very interesting tips here. The new Flickr photo pages suffered from what I’ve been calling “Flash of Un-Behavioured Content”, where slow loading JavaScript results in poor behaviour from some UI controls. They started using “Action Queueing”, where a small JS stub ensures a loading indicator is shown for clicks on features that have not yet fully loaded. Also, it turns out some corporate firewalls (Sonicwall in particular) dislike URLs over 1600 characters, and filter out any URL with xxx in it. # 10th November 2010, 6:33 pm

flXHR. I was looking for something like this recently, glad to see it exists. flXHR is a drop-in replacement for regular XMLHttpRequest which uses an invisible Flash shim to allow cross-domain calls to be made, taking advantage of the Flash crossdomain.xml security model. # 26th November 2009, 12:52 pm

LABjs: new hotness for script loading. Created in collaboration with Steve Souders, LABjs is a JavaScript loading library which makes it easy to have scripts download in parallel while still ensuring that they execute sequentially where required to ensure dependencies are met. It’s unclear how you would decide to use this over concatenating all scripts together in to a single file. # 26th November 2009, 12:28 pm

Request Routing With URI Templates in Node.JS. I quite like this approach (though the implementation is a bit “this” heavy for my taste). JavaScript has no equivalent to Python’s raw strings, so regular expression based routing ala Django ends up being a bit uglier in JavaScript. URI template syntax is more appealing. # 24th November 2009, 9:06 am

Node.js is genuinely exciting

I gave a talk on Friday at Full Frontal, a new one day JavaScript conference in my home town of Brighton. I ended up throwing away my intended topic (JSONP, APIs and cross-domain security) three days before the event in favour of a technology which first crossed my radar less than two weeks ago.

[... 2009 words]

Deep Tracing of Internet Explorer. dynaTrace Ajax looks like an awesome tool. For once, Internet Explorer has a development tool that other browsers can be jealous of. # 18th November 2009, 8:06 am

node.js at (PDF). node.js creator Ryan Dahl’s presentation at this year’s The principle philosophy is that I/O in web applications should be asynchronous—for everything. No blocking for database calls, no blocking for filesystem access. JavaScript is a mainstream programming language with a culture of callback APIs (thanks to the DOM) and is hence ideally suited to building asynchronous frameworks. # 17th November 2009, 6:07 pm

Going evented with Node.js. Comprehensive Node.js tutorial—from basic principles to installation and writing a simple Twitter search command-line client application. # 17th November 2009, 1:09 pm

node.js. “Evented I/O for V8 JavaScript”—a JavaScript environment built on top of the super-fast V8 engine which provides event-based IO functionality for building highly concurrent TCP and HTTP servers. The API design is superb—everything is achieved using JavaScript events and callbacks (even regular file IO) and the small standard library ships with comprehensive support for HTTP and DNS. Overall it’s very similar to Twisted and friends, but JavaScript’s anonymous function syntax feels more natural than the Python equivalent. It compiles cleanly on Snow Leopard. Definitely a project to watch. # 9th November 2009, 11:25 pm

It’s interesting to me how much [Closure] feels like a more advanced version of Dojo in many ways. There’s a familiar package system, the widgets are significantly more mature, and Julie and Ojan’s Editor component rocks. The APIs will feel familiar (if verbose) to Dojo users, the class hierarchies seem natural, and Closure even uses Acme, the Dojo CSS selector engine.

Alex Russell # 6th November 2009, 7:35 am

Introducing Closure Tools. Google have released the pure-JavaScript library, apparently used for Gmail, Google Docs and Google Maps. It comes with a powerful JavaScript optimiser tool with linting built in and an accompanying Firebug extension to ensure the obfuscated code it produces can still be debugged. There’s also a template system which precompiles down to JavaScript and can also be called from Java. # 6th November 2009, 7:33 am

Introducing the YUI 3 Gallery. Write a plugin for YUI3, BSD license it and sign a CLA and Yahoo! will push your module out to their CDN and make it loadable using the YUI().use() statement. They’re coordinating the submissions using GitHub. # 4th November 2009, 11:14 pm 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 to set a different start time for the counter. # 12th November 2008, 4:43 pm

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. # 7th November 2008, 11:23 pm

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. # 7th November 2008, 5:32 pm

Jetty WebServer. Jetty 6.1 was the only cometd / Bayeux implementation I tried which worked out of the box. # 27th November 2007, 6:43 pm

Deconstructing Facebook Beacon JavaScript. How Facebook’s new Beacon service (also known as “Facebook ruined Christmas”) actually works. # 25th November 2007, 9:20 pm

DebugBar. Suggested at BarCamp London 3 as a useful tool for developing with IE; apparently includes a great JavaScript debugger. # 25th November 2007, 10:32 am

A Taxonomy of Event- and REST-based Comet. Kris Zyp describes a conceptual model for Comet messages based on REST semantics (so you can send a PUT referencing a specific URI down to a client to represent an idempotent state change). # 21st November 2007, 8:18 pm

Weewar (Nat v.s. me). Really impressive turn based strategy game, implemented entirely in the browser. Surprisingly addictive; you have been warned. # 20th November 2007, 11:52 pm

IE ActiveX(“htmlfile”) Transport, Part II. Fascinating tricks for working around IE memory leaks using explicit CollectGarbage() calls and setInterval() to an empty function. # 19th November 2007, 11:48 am

JavaScript Beautifier (via) Useful online tool (source code also available) for un-obfuscating JavaScript that has had its whitespace stripped out. # 16th November 2007, 8:43 pm

Yahoo! Search Contextual Precaching. Neat performance trick on Yahoo! Search: the moment you start typing (indicating you intend to search) the site quietly fires off a bunch of requests to precache assets needed for the search results page. # 16th November 2007, 3:58 pm