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Access to Java Fields at DSL [message #1385473]

Fri, 06 June 2014 16:59

Michael Stadler

Messages: 5
Registered: June 2014

Junior Member

Hi,

I want to write a Xtext grammar where the users can access Java Classes and their fields.

e.g.:

Java.Exampleclass: {
field1:"abc",
field2:"def"
}

(field1 and 2 are fields of the Java.Exampleclass)

The reference to the Java Class or interface wasn't a problem to implement. But I've not found a way to get access to fields in the Xtext Editor. These fieldnames should (later) be proposals for the auto completion etc.

It would be great if you can give me a hint.

Thanks in advance!
Michael

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Re: Access to Java Fields at DSL [message #1385475 is a reply to message #1385473]

Fri, 06 June 2014 18:12

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

Hi,

can you give a bit more context what you have done? grammar?

if the reference to class is a JvmDeclaredType you can ask it for its DeclaredFields

e.g.


import "http://www.eclipse.org/xtext/common/JavaVMTypes" as types

Model:
	instances+=Instance*;
	
Instance:
	'instance' name=ID 'of' type=[types::JvmDeclaredType|FQN] '{'
		values+=Value*
	'}';
	
Value:
	field=[types::JvmField] '=' v=STRING
;	

FQN: ID ("." ID)*;

class MyDslScopeProvider extends org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider {

	def IScope scope_Value_field(Instance ctx, EReference r) {
		return Scopes.scopeFor(ctx.type.declaredFields,[
			f|QualifiedName.create(f.simpleName)
		], IScope.NULLSCOPE )
	}

}

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

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Re: Access to Java Fields at DSL [message #1385483 is a reply to message #1385475]

Fri, 06 June 2014 19:32

Michael Stadler

Messages: 5
Registered: June 2014

Junior Member

That's exactly what I was looking for.
Thank you very much!

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Re: Access to Java Fields at DSL [message #1385540 is a reply to message #1385473]

Mon, 09 June 2014 06:14

Michael Stadler

Messages: 5
Registered: June 2014

Junior Member

Hi,

I've two further questions:

I realized, that in the previous example of Christian Dietrich it is just possible to access the fields of exactly this class and the inherited fields (if this java class inherits from another one) are not available. Is it possible to achieve this?

Further, I wanted to check wheter a setter method exists for this field at the java class. But again, unfortunatly I've found no solution.
This aspect can be checked either at the ScopeProvider, or as a Check at the DslValidator.

Thanks again for helping me out
Michael

[Updated on: Mon, 09 June 2014 06:34]

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