Javascript

Unfortunately, the js-ctypes project got back-burnered for a while. Fortunately, some great contributors swooped in and landed some really nice bits. Fredrik Larsson helped out on some Linux problems (bug 416119), filled in ANSI string support (bug 416229) and setup an xpcshell test framework (bug 427286).

If you have an extension that uses mozIJSSubScriptLoader (a mouthful, I know) then you should be aware of a recent change (bug 418356). The mozIJSSubScriptLoader interface can be used from JS to load and run JavaScript code from the given URL at run-time. Previously, the URL could be chrome:, file:, data: or resource:, but due to a security fix, the URL is now limited to chrome: only.

Firefox 3 is not even out the door, but work has started on the next refactoring of the Mozilla platform. Dubbed Mozilla 2 (FF3 is built on Mozilla 1.9), it is a chance to make lots of interesting, even scary, changes to the platform. For some background on Mozilla 2 go back and read Brendan’s post. Also, read the Mozilla 2 wiki pages.

Firefox 3 is using JSON to store data in several places - such as bookmark backups, session restore, and offline manifests. Originally, JSON parsing was scattered through the code. Then it was consolidated to JSON.jsm, a JavaScript code module. Eventually, it was converted into nsIJSON.idl, a C++ XPCOM Component. What does this mean to extension and application developers? Well, you now have access to JSON encoding and decoding routines that can be a lot faster (more in a bit) than the JavaScript counterparts.

We have been putting out the call for extension developers to start the process of updating their extension to workin Firefox 3. It’s never fun when your extension breaks because of changes in Firefox, but everyone wants to make the platform better. In doing so, we had to break some eggs.

I have talked a bit about the new built-in datasources (XML and SQL) developers can use with XUL templating (guide and tutorial). I wanted to wrapup my little foray into XUL template datasources by also talking about custom datasources.

XPCOM - It’s a place most XUL application and extension developers would rather avoid. There are times when XPCOM components are needed and developers have to bite-the-bullet. A few examples are commandline handlers, autocomplete implementations and the new custom query processors for XUL templates. If you’re lucky, you can use JavaScript to implement the XPCOM component.