Eclipse Community Forums: TMF (Xtext) » Manipulating the model in Xtext

Home » Modeling » TMF (Xtext) » Manipulating the model in Xtext

Manipulating the model in Xtext [message #663743]

Wed, 06 April 2011 07:33

Eclipse User

Hello,

This is a rather generic question: I was wondering if you could manipulate in some way the model within the grammar definition.

Let's take a very easy example: suppose that in our metamodel we have an EClass called "Entity" which has a name and a data attributes (both EString).

In our Xtext grammar we have a rule like this for the Entity:

Entity:
   'Entity' name=ID;

Now suppose that I automatically want to assign the name of the Entity to the data attribute (so, in the model in memory we will have an entity with the name and data attribute being the same).

Is this possible to modify the grammar rule to do something like that ?

Of course, in the example here it doesn't have a lot of advantages but sometimes it could be useful to be able to manipulate the model in order to automatically fill some parts of it.

Re: Manipulating the model in Xtext [message #663773 is a reply to message #663743]

Wed, 06 April 2011 09:14

Eclipse User

Hi,

not within the grammar. Usually you would use an imported meta model. Then you can either modify the setters there or hook into the model instantiation.

Alex

Re: Manipulating the model in Xtext [message #663893 is a reply to message #663773]

Wed, 06 April 2011 13:02

Eclipse User

Alex is right.

But if you choose to let Xtext derive the ecore meta model then you can modify the resulting meta model using the post process
hook provided by the framework (an Xtend file named <yourDSL>Postprocessor.ext).

You can find an example for setting default values and adding operations in
http://git.eclipse.org/c/etrice/org.eclipse.etrice.git/tree/ plugins/org.eclipse.etrice.core.room/src/org/eclipse/etrice/ core/RoomPostprocessor.ext

Hope that helps,
Henrik

Am 06.04.2011 15:14, schrieb Alexander Nittka:
> Hi,
>
> not within the grammar. Usually you would use an imported meta model. Then you can either modify the setters there or hook into
> the model instantiation.
> Alex

Re: Manipulating the model in Xtext [message #663900 is a reply to message #663773]

Wed, 06 April 2011 14:37

Eclipse User

Alexander Nittka wrote on Wed, 06 April 2011 09:14

... hook into the model instantiation.

Do you mean to customize the PackageFactory or can u tell me how to affect the model creation?

[Updated on: Wed, 06 April 2011 14:38] by Moderator

Re: Manipulating the model in Xtext [message #663910 is a reply to message #663900]

Wed, 06 April 2011 15:08

Eclipse User

Hi,

I think one of the recommended ways is to do simple changes during the linking phase (check the methods in AbstractCleaningLinker and the classes extending it).

Alex

Previous Topic:	Re: [Xtext2] Extending Xbase expressions
Next Topic:	Internationalisation of ecore plugin language variables

Goto Forum:

-=] Back to Top [=-

Current Time: Fri Jul 04 20:29:38 EDT 2025

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter