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generate property from referenced object [message #1293652]

Sat, 12 April 2014 21:08

Chris Klein

Messages: 3
Registered: April 2014

Junior Member

Hi,

my first adventures in xtext were very positive. The plugin was working in an instant and its a pleasure to use ones own language using an inteligent editor.

But now i got stuck using referenced rules. Taking the 15 minutes example i would like to do something like:

Entity :
  'entity' name = ID 
;

Entity2 :
  'entity2' name = [Entity] 
;

The rule Entity2 doesnt work as expected. I think its because [Entity] returns the referenced object but not a string.

The Objects of entity2 should have the same name as the referenced Entity object. In other languages i'd use a statement like

Entity2 :
  'entity2' name = [Entity].name
;

But, of course, this doesnt work too.

I hope i have made my point clear. Does XText allow to do something like this in grammar only? Or do I have to change some java internals of the editor?

Thanks in advance for your help,

chris

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Re: generate property from referenced object [message #1294839 is a reply to message #1293652]

Sun, 13 April 2014 21:17

Christian Dietrich

Messages: 13314
Registered: July 2009

Senior Member

Hi you have to adapt the iqualifiednameprovider (subxlassing
DefaultDeclarativeQualifiedNameProvider) and use NodeModelUtil
(findNodesForFeature) to extract the cross referenced name string

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Re: generate property from referenced object [message #1296048 is a reply to message #1294839]

Mon, 14 April 2014 19:41

Chris Klein

Messages: 3
Registered: April 2014

Junior Member

Hi christian,

thanks for the pointers. Using your keywords i found your blog post under

christiandietrich.wordpress.com/2011/07/16/iqualifiednameproviders-in-xtext-2-0/

that shows how to use the DefaultDeclarativeQualifiedNameProvider

I implemented qualifiedName as follows

     QualifiedName qualifiedName(Entity2 e) {
    	 List<INode> nl=NodeModelUtils.findNodesForFeature(e,
	e.eClass().getEStructuralFeature(skoL.dsl.impl.DslPackageImpl.ENTITY2__REF));
    	INode node=nl.get(0);
    	 String vName=node.getText();
    	 
    	 EObject temp = e;
		while (temp.eContainer() != null) {
			temp = temp.eContainer();
			QualifiedName parentsQualifiedName = getFullyQualifiedName(temp);
			if (parentsQualifiedName != null)
				return parentsQualifiedName.append(vName);
		}
        return QualifiedName.create(vName);
    }

this makes Entity2 visible in the global object list (under ctrl+shift+f3).

But I still have one problem: Entity2 Objects dont show up in auto-completion.(ctrl+space) I suspect this is due to entity2 objects having no attribute called "name". How can I make the objects appear in auto-complete?

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Re: generate property from referenced object [message #1296064 is a reply to message #1296048]

Mon, 14 April 2014 19:56

Christian Dietrich

Messages: 13314
Registered: July 2009

Senior Member

Please share a complete reproducible example. I can't follow your
problem

--
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Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/xtext/
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Re: generate property from referenced object [message #1296747 is a reply to message #1296064]

Tue, 15 April 2014 07:01

Christian Dietrich

Messages: 13314
Registered: July 2009

Senior Member

P:S: if they are in the global index the shall occury locally too (if your grammar is correct)

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/xtext/
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Blog : https://www.dietrich-it.de

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Re: generate property from referenced object [message #1307704 is a reply to message #1296747]

Mon, 21 April 2014 18:42

Chris Klein

Messages: 3
Registered: April 2014

Junior Member

i solved the problem:

following instructions on

malubu.wordpress.com/2012/05/07/post-processing-vs-post-initialization/

i added a "name" property to my Entity2 object and now it shows up in auto-completion

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