Comments on: Retrieving Your Extension Version

By: Mook

Mook — Tue, 06 Jan 2009 16:13:16 +0000

It may also be important to note that, just like all the three million other interfaces in Mozilla, nsIExtensionManager isn’t frozen. Or maybe it isn’t important; it’s up to the extension developer to decide :)

By: DigDug

DigDug — Tue, 06 Jan 2009 14:13:40 +0000

FUEL support something like this too.

Application.extensions.get(“myext@foo.com”).version

Of course that’s Firefox only and won’t work in older versions I guess?

By: Wladimir Palant

Wladimir Palant — Tue, 06 Jan 2009 10:56:41 +0000

Unfortunately, things aren’t as easy if you have to support SeaMonkey 1.1 (or K-Meleon, for that reason). There is a way to retrieve extension version there as well but it is too unreliable so I decided to hardcode. The version number is filled in by my build scripts everywhere anyway so it doesn’t matter.

By: Axel Hecht

Axel Hecht — Tue, 06 Jan 2009 10:54:00 +0000

Seems like you missed install.rdf in the ems? Using FUEL Extensions would make the code easier still, I think.

By: Mossop

Mossop — Tue, 06 Jan 2009 10:53:11 +0000

Daniel, this is already on MDC, though I grant you it could probably do with being somewhere better:

https://developer.mozilla.org/en/Code_snippets/Miscellaneous#Retrieving_the_version_of_an_extension_as_specified_in_the_extension%27s_install.rdf

By: Mossop

Mossop — Tue, 06 Jan 2009 10:50:18 +0000

It is worth pointing out that there are still good reasons why hardcoding can be the better option, particularly if you have some automated build system that can take care of updating your version everywhere for you.

The problem is one of performance. In normal running the extensions database isn’t loaded until absolutely necessary, the first script to call getItemForID will however force it to load. This costs some 20ms on a fairly fast machine with just 5 add-ons installed. It is something to be wary of if your version check runs during startup.

By: Daniel Glazman

Daniel Glazman — Tue, 06 Jan 2009 10:11:44 +0000

May I suggest you create an article on devmo with that?