[news.eclipse.tools.emf] Re: OCL checker for EMF models in transformatio

[Damien Thivolle <damien.thivolle@xxxxxxxx>]

Ed Merks a écrit :
> Damien,
>
> Comments below.

Thanks!
> Damien Thivolle wrote:
> > Hello,
> >
> > I'm relatively new to Eclipse and the modeling technology. I want to 
> > write a transformation from a meta-model MMa to a meta-model MMb using 
> > ATL. The problem is that the transformation will only concern a subset 
> > of MMa.
> There's a newsgroup for ATL.  I've included it on the "to" list of the 
> reply.

Thank you but I don't have any problems with ATL and I'm in close 
contact with the ATLAS team anyway.

> > I've been hinted to write a checker in OCL that would just tell me 
> > whether a model Ma (conforming to MMa) is included in the subset I'm 
> > interested in.
> >
> > In the end, if the checker answers true when asked if the input model 
> > is correct, the transformation would take place, if not an error 
> > message would be yielded.
> >
> > I've been looking for some clues as to where to start and I was 
> > expecting to find something suitable for a newbie like me. Like, I 
> > define a file with a set of OCL constraints, right click on my model 
> > and choose "Validate constraints from file...". But I guess it's not 
> > gonna be that easy.
> >
> > More generally, I'm having a hard time finding my way around Eclipse, 
> > EMF and such... I've been reading all the material I could find about 
> > using OCL to check constraints on EMF models, and it's like Chinese to 
> > me.
> Note really.  If it were Chinese it would use an alphabet you'd not 
> recognize.  :-P

Yeah, sorry about my whining :) It's just that usually with Eclipse, the 
documentation gives you a lot of examples as starting points. But too 
often, there aren't enough explanations to make you really understand 
what you're doing (see the doc for the OCL environment class which takes 
 12 template parameters...).

> > For example, I've seen a lot of EMF models with annotations named 
> > "OCL" and having several entries, but I can't really find anything 
> > that would explain me what to do with those.
> Did you look at the Eclipse help?
> > I'm just saying is that I find it hard to understand this technology 
> > and I'm wondering if it's normal or if this is where my comprehension 
> > reaches its limits.
> There's an awful lot of technology to learn all at once for sure.  And 
> the documentation is sometimes a little lacking or hard to find...

My models are in files with a .sam extension and I want to write an ocl 
file with constraints for my models. The SAM meta-model is written in Ecore.

So I was thinking I could implement a contextual menu action that would 
only be available for files with a .sam extension. When handling that 
action, I would open that model file in JAVA as you explained in one of 
your previous messages on this newsgroup 
(<fmnq3n$qrm$1@xxxxxxxxxxxxxxxxx>). Then I would ask the user to choose 
an ocl file and would use the OCL Eclipse project to open that OCL file, 
parse it and verify the constraints on my SAM model. Does that sound 
alright or is there a better way to do it?

For now, I'll forget about the transformation chain, I'll implement the 
constraints checker and the ATL transformation separately and then, I 
will think about how to "connect" them.

Best regards,

--
Damien THIVOLLE                   |     INRIA Rhone-Alpes / VASY
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