@Override
	public void afterSave(XtextEditor editor) {
		// TODO Auto-generated method stub
		

		IXtextDocument myDocument = editor.getDocument();
		myDocument.modify(new IUnitOfWork<Void, XtextResource>() {
			@Override
			public java.lang.Void exec(XtextResource res) throws Exception {
				ContentModel mymodel =(ContentModel) res.getContents().get(0);
				mymodel.setName(mymodel.getDisplayName().toString().intern());
				System.out.println(mymodel.getDisplayName().toString());
				
				return null;
			}
		});	

package org.xtext.example.mydsl.ui;

import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.xtext.builder.nature.NatureAddingEditorCallback;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.ui.editor.XtextEditor;
import org.eclipse.xtext.util.concurrent.IUnitOfWork;
import org.xtext.example.mydsl.myDsl.Greeting;
import org.xtext.example.mydsl.myDsl.Model;

public class MyDslEditorCallback extends NatureAddingEditorCallback {
	

	@Override
	public void afterSave(XtextEditor editor) {
		System.out.println("here we go");
		editor.getDocument().modify(new IUnitOfWork<Void, XtextResource>() {

			@Override
			public java.lang.Void exec(XtextResource state) throws Exception {
				for (Greeting g : ((Model)state.getContents().get(0)).getGreetings()) {
					g.setName(g.getName().toUpperCase());
				}
				return null;
			}
			
		});
		if (isDirty()) {
			editor.doSave(new NullProgressMonitor());
		}
		super.afterSave(editor);
		
	}


}

@Override
	public Class<? extends org.eclipse.xtext.ui.editor.IXtextEditorCallback> bindIXtextEditorCallback() {
		return org.eclipse.xtext.builder.nature.NatureAddingEditorCallback.class;
	}
	
	public Class<? extends EditorCallback> bindModulefileBuilder() {
	     return EditorCallback.class;

public class EditorCallback extends NatureAddingEditorCallback {
	@Override
	public void afterSave(XtextEditor editor) {
		System.out.println("here we go");
		editor.getDocument().modify(new IUnitOfWork<Void, XtextResource>() {
          
			@Override
			public java.lang.Void exec(XtextResource state) throws Exception {
				ContentModel mymodel = ((ContentModel) state.getContents().get(0));
				System.out.println(mymodel);
				mymodel.setName(mymodel.getDisplayName().toString());
				
				return null;
				
			}
			
		});
		if (isDirty()) {
			editor.doSave(new NullProgressMonitor());
		}
		super.afterSave(editor);
		
	}

@Override
			public java.lang.Void exec(XtextResource state) throws Exception {
		    // WebApplication mymodel1 = ((WebApplication) state.getContents().get(0));
				
			//	System.out.println(mymodel1);
				
				//mymodel.setName(mymodel.getDisplayName().toString());
				
				ContentModel mymodel =(ContentModel) state.getContents().get(0);
                 
				if(mymodel.getDisplayName().equals(null) || mymodel.getDisplayName().equals("")){
			    	mymodel.setDisplayName(mymodel.getName());
			  
				}
				
				return null;
				
			}
			
		});
		if (isDirty()) {
			editor.doSave(new NullProgressMonitor());
		}
		super.afterSave(editor);
		
	}

ContentModel returns ContentModel:
	'ContentModel'
	name=QualifiedName
	'{'
	'guID' '=' guID=STRING
	'displayName' '=' displayName=STRING
	('description' '=' description=STRING)?
	ownedWebApplication=WebApplication
	'}';
	
ContentUnit returns ContentUnit:
	ContentModel | WebApplication | SiteCollection | Web | CustomList | ContentType | Field | View;

WebApplication returns WebApplication:
	'WebApplication'
	name=QualifiedName
	'{'
	'guID' '=' guID=STRING
	'displayName' '=' displayName=STRING
	('description' '=' description=STRING)?
	ownedSiteColection+=SiteCollection (ownedSiteColection+=SiteCollection)*
	'}';

SiteCollection returns SiteCollection:
	'SiteCollection'
	name=QualifiedName
	'{'
	'guID' '=' guID=STRING
	'displayName' '=' displayName=STRING
	('description' '=' description=STRING)?
	ownedWeb=Web
	'}';

protected boolean createNewEntity(Entity sibling, String name) {
		Entity newEntity = DomainmodelFactory.eINSTANCE.createEntity();
		newEntity.setName(name);
		return addTypeAsSibling(sibling, newEntity);
	}

	protected boolean createNewDatatype(Entity sibling, String name) {
		DataType newDatatype = DomainmodelFactory.eINSTANCE.createDataType();
		newDatatype.setName(name);
		return addTypeAsSibling(sibling, newDatatype);
	}

	protected boolean addTypeAsSibling(Entity sibling, Type newType) {
		EObject container = sibling.eContainer();
		EList<AbstractElement> elements = null;
		if (container instanceof PackageDeclaration) {
			elements = ((PackageDeclaration) container).getElements();
		} else if (container instanceof DomainModel) {
			elements = ((DomainModel) container).getElements();
		} else {
			return false;
		}
		int index = elements.indexOf(sibling) + 1;
		elements.add(index, newType);
		return true;
	}
}