grammar org.eclipse.xtext.example.domainmodel.Domainmodel with org.eclipse.xtext.xbase.Xbase

generate domainmodel "[interpreted as link]/example/Domainmodel"

DomainModel:
	'package' packageName=QualifiedName
	importSection=XImportSection?
	elements+=Entity*
	usages+=Usage*
	
;
	
Entity:
    "entity" name=ValidID "{"
        features+=Feature*
    "}"
;
 
Feature:
    Attribute | Reference
;
 
Attribute:
    "attr" name=ValidID ":" type=DataType
;
 
enum DataType:
    string | int
;
 
Reference:
    "ref" name=ValidID ":" type=[Entity|QualifiedName]
;

Usage:
    "use" ref=DotExpression
;
 
DotExpression returns Ref:
    EntityRef ({DotExpression.ref=current}  "." tail=[Feature])*
;
 
EntityRef returns Ref:
    {EntityRef} entity=[Entity]
; 

package myFirstPackage

entity myFirstEntity {
	attr value : int	
}

package mySecondPackage
import myFirstPackage.*

entity mySecondEntity {
	attr myAttr : int
	ref myRef : myFirstEntity
}

use mySecondEntity.myRef

class MyDslScopeProvider extends XbaseBatchScopeProvider {

	override getScope(EObject context, EReference reference) {
		if (context instanceof DotExpression) {
			return scope_DotExpression_tail(context, reference)
		}
		super.getScope(context, reference)
	}

	def IScope scope_DotExpression_tail(DotExpression exp, EReference ref) {
		val head = exp.ref;
		switch (head) {
			EntityRef : Scopes::scopeFor(head.entity.features)
			DotExpression : {
				val tail = head.tail
				switch (tail) {
					Attribute : IScope::NULLSCOPE
					Reference : Scopes::scopeFor(tail.type.features)
					default: IScope::NULLSCOPE
				}
			}
			
			default: IScope::NULLSCOPE
		}
	}
	
}

public class MyDslRuntimeModule extends org.xtext.example.mydsl.AbstractMyDslRuntimeModule {

	public Class<? extends IBatchScopeProvider> bindIBatchScopeProvider() {
		return MyDslScopeProvider.class;
	}
	
}