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Retrieve info from EMF model in UI action and then use it to modify the model itself [message #1006055]

Tue, 29 January 2013 16:13

Marco Naddeo

Messages: 62
Registered: November 2012

Member

Hi.

In an UI action in my DSL editor, I want to retrieve some information from the EMF model and then use it later to modify the model itself.

My code is something like this:

public class MyHandler extends AbstractHandler implements IHandler {

  @Override
  public Object execute(ExecutionEvent event) throws ExecutionException {

    final XtextEditor xtextEditor = (XtextEditor) HandlerUtil.getActiveEditor(event);

    final String info = xtextEditor.getDocument().readOnly(new IUnitOfWork<String,XtextResource>() {
			
      @Override
      public String exec(XtextResource state) throws Exception {

        TreeIterator<EObject> iter = state.getAllContents();
        String res = "";

        while (iter.hasNext()) {

	  EObject obj = iter.next();

	  if (...) {

            res = obj.getMyFeature();

          }

        }
        return res;

      }
			
    });


    //do some work here...

    //and then:
    xtextEditor.getDocument().modify(new IUnitOfWork.Void<XtextResource>() {

      @Override
      public void process(XtextResource state) throws Exception {

        TreeIterator<EObject> iter = state.getAllContents();

        while (iter.hasNext()) {

	  EObject obj = iter.next();

	  if (...) {

            obj.setMyFeature(info);

          }

        }

      }

    });

  }

}

The setting of the model element feature with the previous retrieved string *seems* to work, but to the next call of the UI action, the feature turns out to be actually set to null! Shocked

Do you have any idea of why? Confused

Note that I'm forced to declare the info string variable as final because the compiler says that I cannot refer to a non-final variable inside an inner class defined in a different method. Is it possible that this affects the result?

Thanks in advance,
Marco Rolling Eyes