grammar org.xtext.example.mydsl.MyDsl with org.eclipse.xtext.common.Terminals hidden(WS, ML_COMMENT, SL_COMMENT, TEST_STMT)

generate myDsl "http://www.xtext.org/example/mydsl/MyDsl"

Model:
	conts+=Cont* procs+=Proc*;
	
Cont:
	'Cont' name=ID '{' items+=Item* '}' ;

Item: 'Item' name=ID;


Proc:
	'Link' item1=[Item|ID] 'OF' con1=[Cont|ID] 'TO' item2=[Item|ID] 'OF' con2=[Cont|ID]
;

//Test  statement
terminal TEST_STMT :  'FreeText: ' ->  '.';

Cont container1 {	
	Item item1
	
}

Cont container2 {
	Item item2
}  

Link item1 OF container1 TO item2 OF container2

import static org.eclipse.ltk.core.refactoring.RefactoringStatus.ERROR;
import static org.eclipse.ltk.core.refactoring.RefactoringStatus.WARNING;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.xtext.CrossReference;
import org.eclipse.xtext.GrammarUtil;
import org.eclipse.xtext.conversion.IValueConverterService;
import org.eclipse.xtext.conversion.ValueConverterException;
import org.eclipse.xtext.linking.impl.LinkingHelper;
import org.eclipse.xtext.naming.IQualifiedNameConverter;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.scoping.IScope;
import org.eclipse.xtext.scoping.IScopeProvider;
import org.eclipse.xtext.serializer.tokens.SerializerScopeProviderBinding;
import org.eclipse.xtext.ui.refactoring.impl.RefactoringCrossReferenceSerializer;
import org.eclipse.xtext.ui.refactoring.impl.StatusWrapper;
import org.eclipse.xtext.ui.refactoring.impl.RefactoringCrossReferenceSerializer.RefTextEvaluator;
import org.eclipse.xtext.util.ITextRegion;
import org.eclipse.xtext.xbase.lib.IterableExtensions;

import com.google.inject.Inject;

public class CustomRefactoringCrossReferenceSerializer extends RefactoringCrossReferenceSerializer {

	private static final Logger log = Logger.getLogger(CustomRefactoringCrossReferenceSerializer.class);
	
	@Inject
	@SerializerScopeProviderBinding
	private IScopeProvider scopeProvider;

	@Inject
	private IValueConverterService valueConverter;

	@Inject
	private LinkingHelper linkingHelper;

	@Inject
	private IQualifiedNameConverter qualifiedNameConverter;

	public String getCrossRefText(EObject owner, CrossReference crossref, EObject target,
			RefTextEvaluator refTextEvaluator, ITextRegion linkTextRegion, StatusWrapper status) {
		try {
			final EReference ref = GrammarUtil.getReference(crossref, owner.eClass());
			final IScope scope = scopeProvider.getScope(owner, ref);
			if (scope == null) {
				throw new IllegalStateException("Could not create scope for the given cross reference.");
			}
			String ruleName = linkingHelper.getRuleNameFrom(crossref);
			
			/*
			 *  Code added here
			 */
			// Getting all elements in the scope
			Iterable<IEObjectDescription> allElements = scope.getAllElements();			
			List<String> names = new ArrayList<>();		
			// Check for duplicate names after refactoring
			for(IEObjectDescription desc : allElements) {
				String unconvertedRefText = qualifiedNameConverter.toString(desc.getName());
				String convertedRefText = valueConverter.toString(unconvertedRefText, ruleName);
				if(names.contains(convertedRefText)) {
					return null;
				} else {
					names.add(convertedRefText);
				}
			}
			/*
			 *  Ends here
			 */
			
			Iterable<IEObjectDescription> descriptionsForCrossRef = scope.getElements(target);
			String bestRefText = null;
			List<String> badNames = new ArrayList<String>();
			for (IEObjectDescription desc : descriptionsForCrossRef) {
				try {
					String unconvertedRefText = qualifiedNameConverter.toString(desc.getName());
					String convertedRefText = valueConverter.toString(unconvertedRefText, ruleName);
					if (refTextEvaluator.isValid(desc) && (bestRefText == null || refTextEvaluator.isBetterThan(convertedRefText, bestRefText)))
						bestRefText = convertedRefText;
				} catch (ValueConverterException e) {
					// this is a problem only if we don't find any matching value
					badNames.add(desc.getName().toString());
				}
			}
			if (bestRefText == null && !badNames.isEmpty()) {
				status.add(WARNING,
						"Misconfigured language: New reference text has invalid syntax. Following names are in the scope: " + IterableExtensions.join(badNames, ", "), owner, linkTextRegion);
			}
			return bestRefText;

		} catch (Exception exc) {
			log.error(exc.getMessage(), exc);
			status.add(ERROR, exc.getMessage(), owner, linkTextRegion);
			return null;
		}
	}
}