http://www.ashita.org Thu, 22 Apr 2010 17:21:34 +0000 http://backend.userland.com/rss092 en This post draws heavily on a question and answer on "An observer for URL changes (Firefox extension)" from StackOverflow. In this post, however, I'm going to focus only on getting the window from which an http request originated. What you need to know Yesterday's post about XHR Listening by a Firefox Addon gives ... http://www.ashita.org/getting-the-source-window-of-a-request/ The following post draws significantly from a post by Jan Odvarko at http://www.softwareishard.com/blog/firebug/nsitraceablechannel-intercept-http-traffic/ but goes a bit further. There are also some sections which were inspired by Firebug, but are heavily modified. What you need to know Before I get into the code, understand that one of the most important things in ... http://www.ashita.org/howto-xhr-listening-by-a-firefox-addon/ There are lots of cases when it is desirable to implement one of the XPCOM interfaces in use by Firefox, or other mozilla-based browsers. There are three cases where PirateQuesting does so, but once you see the concept, it should be easy to adapt to your situation. You must have a ... http://www.ashita.org/implementing-an-xpcom-firefox-interface-and-creating-observers/ I use singletons all over the PirateQuesting code, but I've never explained the idea here, nor how they are different from singletons in other languages. Anyone familiar with common design patterns knows how singletons work in the vast majority of languages. For a PHP example, see this post. In JavaScript ... http://www.ashita.org/singletons-in-javascript/ I write PHP regularly in my job, but this is the first post on Ashita.org on a PHP subject. One interesting problem recently was how to make Singletons in PHP from a generic base class and extended where necessary. First, an introduction: Singletons are an incredibly common and useful design ... http://www.ashita.org/singletons-in-php/ I've been a fan of both Prototype and JQuery for a while and have no qualms recommending either. They do have somewhat different aims, and as such it's a good idea to consider carefully which one best meets the needs of your project (or if you even need either to ... http://www.ashita.org/prototypes-bind-and-curry/ Here's something pretty easy to use, useful, and strangely not as common as you would expect. JavaScript has an operator known as the "default" operator and is the same as the logical-or operator. That's right. ||. First, some examples of how we can use it: var value_1 = false || 2; var value_2 = ... http://www.ashita.org/javascripts-default-operator/ When making Firefox extensions with modular components, it's nice to be able to include overlays based on preferences or some other criteria at loadtime. One of the problems that quickly comes up is that sequential loadOverlay calls will fail. This bug is documented here. The solution described there, and elsewhere, ... http://www.ashita.org/the-loadoverlay-dilemma/ I last wrote about closures and how this affects the visibility of variables and functions. This time I'm going to introduce returning functions from a closure and how it can be useful in the first part. First off, lets say you have a strange need to create functions to consistently ... http://www.ashita.org/functions-in-closures/ Closures are one of the most powerful features of JavaScript. JavaScript isn't the only language supporting this, but it's certainly the one I'm going to discuss here. Just for example, the same thing can be done in ActionScript 3 -- if you know how that works, you know how it ... http://www.ashita.org/javascript-closures/