Quick Performance Tip: jQuery and addClass

Abstractions are helpful and dangerous. But the more we know about a library’s internals, the less danger we’ll be in later. Here’s an issue I ran into where I had assumed that jQuery would be optimized for this case, but it wasn’t. I’ll go over my bad assumption and how to workaround it.

As of jQuery 1.3.2, adding multiple HTML classes to an element using jQuery’s addClass method will add them one at

Adobe Reverts Flex Store to Open Web

A few weeks ago in the process of doing some research about the Adobe Flex platform, I came across their online store, a dogfooded full page application using Flex.

This morning I went back to the same URL to find a site that was no longer using the full page Flex application I had been expecting. Instead it was now using native Open Web technology.

Naturally, my first assumption was that I had hallucinated the

Performance Caveat with jQuery Selectors and Live Events

Prerequisite: Knowledge/Experience with jQuery Live Events (new in jQuery 1.3), and the concept of Event Delegation.

When developing on the front end, it’s easy to prioritize correctness over performance. Performance is the step child that gets lost while you’re pulling your hair out worrying about cross browser compatibility. It’s very important to regularly benchmark your JavaScript code, using a profiler or some form of benchmarking code paired with a cross browser