topic Re: BPMN model transformation and back in Alfresco Archive

BPMN model transformation and back

norberts — Wed, 10 Apr 2013 09:35:43 GMT

I'm working on a plugin for Activiti where I can model limited BPMN processes in Activiti and then transform them via my plugin to an internally used workflow graph representation. On that workflow graph I want to run analyses and small further transformations (combination of elements to new ones, s

Re: BPMN model transformation and back

tiesebarrell — Wed, 10 Apr 2013 11:30:05 GMT

I would re-enable the ExportMarshaller extension point rather than the validation one, but that doesn't really matter as long as you have a hook to get the model somewhere.

Are you sure you want to show it in the same editor? That would quickly become a mess because you're changing the underlying model and hotswapping the display. This is not typically how Eclipse editors work. Another way to approach this would be to simply enrich the model and then export to a separate BPMN file (which you overwrite each time), living alongside the BPMN file you've opened in the editor. To show that enriched diagram, you simply open the new file with the diagram editor. Then you get all of the editor functionality straight out of the box.

Re: BPMN model transformation and back

norberts — Wed, 10 Apr 2013 20:15:45 GMT

So, you suggest that you have two files open in the end? But then the same problem happens again, that the second editor should respond to internal changes of the model..
I thought you can change the underlying model and the UI changes to this. Just the normal Model-View pattern. 😕 But I have a hard time to even see how the model is displayed in the Activiti Editor so I get the feeling I am totally wrong here. Not to mention the creation of my own BPMN model or process, that is marshalled correctly into a file using the provided BPMN marshaller.

Re: BPMN model transformation and back

tiesebarrell — Wed, 10 Apr 2013 20:19:43 GMT

Well, the idea would be that you edit the one, and the second results from that. That avoids having the recursive behavior you mention.

I don't see the problem with generating the BPMN. Aren't you creating something that's BPMN anyway in the enrichment? Then you can simply use the default marshalling from the model, because that's all provided if it's valid BPMN.

Re: BPMN model transformation and back

norberts — Thu, 11 Apr 2013 11:42:23 GMT

Alright, I'm not sure if you got my idea correct or I don't get yours completely.

Anyway, I kind of succeeded on what I want as a first try. I changed the existing model by just adding a user task. For that I created a new UserTask object and added a new pictogram element surrounded by a new RecordingCommand in the editingDomain of the editor. The addFeature is of type AddTaskFeature from Activiti and is handling the look on it's own. Thanks for that.

activeEditor.getEditingDomain().getCommandStack()
  .execute(new RecordingCommand(activeEditor.getEditingDomain()) {
    @Override
    protected void doExecute() {
       final AddContext context = new AddContext(new AreaContext(), userTask);
       final IAddFeature addFeature = featureProvider.getAddFeature(context);
       context.setNewObject(userTask);
       context.setLocation(x, y);
       context.setTargetContainer(diagram);
       if (addFeature.canAdd(context)) {
              final PictogramElement add = addFeature.add(context);
              featureProvider.link(add, new Object[] { userTask });
       }
    }
});

The userTask object is also added to the flowElement list of the process in the model.
In the end I call activeEditor.updateDirtyState(); on the editor and it is displayed.
The marshaller also exports it correctly to the xml file.

Re: BPMN model transformation and back

tiesebarrell — Thu, 11 Apr 2013 13:21:24 GMT

OK, cool looks like you got started.