Re: [imp-dev] "Interesting" case of dynamic language registration

[Jurgen Vinju <Jurgen.Vinju@xxxxxx>]

Hi,

That service about bundle startup does not help (it's too late, since
the editors may have already been started before the bundle does).

Instead there is now an extension point called languageRegistrar which
calls a method in classes that implements ILanguageRegistrar at the
right moment in time (when UniversalEditor for the first time needs to
call findLanguage on LanguageRegistry). It's been tested and checked
into the trunk.

Thanks!

Jurgen

On Tue, Dec 7, 2010 at 3:06 PM, Robert M. Fuhrer <rfuhrer@xxxxxxxxxxxxxx> wrote:
> [ This conversation also took place on Bugzilla bug Bug 331751]
>
> [ Ooh, the meta-ness of all of this is giving me chills. :-) You want to
> extend the
> extension mechanism... ]
> This sounds entirely reasonable to me. In essence, given that we already
> support dynamically registering languages, you now need a way to trigger
> that
> early enough at startup.
> Here's my first-cut proposal:
> Let's create an extension point for the following interface:
>   public interface LanguageRegistrar {
>       public void registerLanguages(LanguageRegistry registry);
>   }
> This would be called by the LanguageRegistry after the normal registration
> process is complete.
> Sound good?
> ==============
> BTW, I don't know that the following helps any, but I've recently committed
> changes to support dynamic language registration when bundles are
> activated/deactivated. I've been using this as part of my work on
> resuscitating
> the source formatting rule editor. The editor can now be run in the same
> workbench as the rest of IMP!
> Seems to work pretty well, though I still have to fix a bug or two in some
> code
> that asks the PDE for all the defined extensions (installed +
> workspace-resident).
> On Dec 2, 2010, at 3:53 PM, Jurgen Vinju wrote:
>
> Hi,
>
> I'm using LanguageRegistry.registerLanguage(...) to dynamically extend
> Eclipse with editors for new languages. The extension points of such
> languages are implemented by some "multiplexing" instances of the IMP
> services that dynamically find the right implementation for each
> editor, based on the language name and some lookup table. These
> implementations are provided by Rascal programs.
>
> So far so good ;-) This all works fine when you're running Eclipse and
> you don't quit it.
>
> Now when I quit Eclipse and start it up again, the editors for those
> dynamically registered languages might still be there. However, since
> their language is not registered by an IMP extension point, there is
> no language registered for those editors and NullPointerExceptions
> start jumping at you from all parts of the UniversalEditor :-(
>
> The question is: where would you add some code that can re-register
> those languages, just in time before the UniversalEditors that are
> still open will start complaining about missing languages? I don't
> think there is a default Eclipse way to do it, and UniversalEditor
> does not provide a service for it either. Your advice is much
> appreciated. (I really can't/shouldn't/won't add extension points for
> those languages). Is there a simple solution?
>
> Cheers,
>
> Jurgen
>
> Cheers,
>  - Bob
>
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>



-- 
Jurgen Vinju
- Centrum Wiskunde & Informatica - SEN1
- INRIA Lille - ATEAMS
- Universiteit van Amsterdam

  www: http://jurgen.vinju.org,
http://www.rascal-mpl.nl,http://twitter.com/jurgenvinju
skype: jurgen.vinju