I have filed and taken several bugs having to do with extensions and the GRE, and I would like to outline my plans for GRE extensions (and extensions in general) so that people may comment. Please reply to n.p.m.xpinstall, and not to the bugs, unless you have a patch or implementation comment. The overarching bug is bug 209439.
Definitions: "extension" == a browser addon or utility (installed with XPInstall)
My plan has the following goals:
1) allow extensions to be registered with a GRE, so that they can be made available to multiple applications using the GRE
2) allow extensions to be installed into their own directories, instead of being installed in the same directory as an application
3) allow extensions (which use only frozen interfaces) to work with multiple versions of the GRE
4) allow extensions to be un-installed
Currently, extensions "piggyback" on top of an application's chrome and components directories. This makes it difficult/impossible to un-install extensions. Instead, it should not be difficult for extensions to maintain their own chrome and components locations.
Implementation-prerequisites:
1) The chrome: service needs to be extended to register arbitrary chrome directories (bug 210838)
Implementation:
Each extension would have an RDF file describing itself. The GRE would include an nsIExtensionManager service, which would allow applications to enumerate/discover available extensions, register extensions, and enable/disable extensions as necessary. The GRE would not contain any UI for extensions; any UI would be managed by applications. There would also be a little command-line utility with the GRE that would register extensions.
Extensions would not be enabled by default; instead, after the application initializes the GRE, it would need to use the nsIExtensionManager to enable the extensions that it wished to use.
Although every extension could use this mechanism, extensions meant for multiple applications would benefit most from this scheme. Some important examples would include:
DOM Inspector
Venkman
JSLib
tranformiix
I feel that GRE extensions are necessary, in order for the new roadmap to be implemented effectively.
--BDS
P.S. Can I also argue that there ought to be a second alpha before 1.5beta? Not much of the current roadmap has been completed yet, and we're going to freeze 1.5a on Wednesday... how about another month and then 1.5a2?
Hyatt wrote something about changing the extension interface in Firebird (http://weblogs.mozillazine.org/dave/archives/2003_06.html#003557), he also got a lot of comments.
You should really coordinate your work with him so that Firebird don't get one implementation and GRE a different one. Actually, you should decide where it is best to keep different extensions before going any further.
-- Kjetil W.
