Re: [epsilon-dev] Concordance Model object creation

[Maarten Bezemer <maarten.bezemer@xxxxxxxxx>]

On Tuesday 11 February 2014 11:15:59 Dimitris Kolovos wrote:

> To avoid confusion I'd suggest calling it an IConcoranceModel instead
> as there's already an IModel in Epsilon
> 
http://dev.eclipse.org/svnroot/modeling/org.eclipse.epsilon/trunk/plugins/org.eclipse.epsilon.eol.engine/src/org/eclipse/epsilon/eol/models/IModel.java

I indeed noticed the other IModel interface, AFAIK there is also another Model 
class. I could also rename the concordance Model class to 
ConcordanceModelImpl.

> >> Next thing is to be able (as an user of Epsilon/Concordance) to provide a
> >> custom implementation of the Model interface.
> >> Currently, I used an extension point to register my custom factory
> >> (implementing a new IModelFactory interface) which creates my custom
> >> implementation of IModel.
> >> 
> >> This works nicely and is least intrusive I think.
> >> By default the ModelFactory implementation is used creating the
> >> default/current Model objects. So nothing changes for existing users.
> >> 
> >> But, (mis)using an extension point to 'configure' the ModelFactory seems
> >> wrong? Instead a public static method could be called to register the
> >> factory, although this does not seem very nice as well and might result
> >> in
> >> the default factory being used until the call is made (which might also
> >> be
> >> the case using extension points...)
> 
> One option would be to introduce a preference page that would allow
> users to select the model factory they'd like to use (extenders would
> still contribute model factories through the extension point).

Letting the user choose the IConcordanceModel implementation does not make 
much sense:
 * Without the correct implementation applications (might) break (applications 
must choose)
 * Users do not care what model implementation is used, it just need to work.

So, I do not think that a preference page is the way to go..?

Another possibility (to circumvent extension points) would be to directly call 
a (static) method of the IConcordanceModel factory, to 'configure' the required 
model type. But personally I (slightly) like the extension point better, as 
this seems more 'natural' and less of a hack.

Cheers,
  Maarten