Tutorial - Converting Eclipse EMF Models to Custom XML

First off, I think EMF is great! It provides a great basis for Model Driven Architecture, which we all know is very cool.

While my first post about EMF really should be about how to use it, I believe that any developer should be able to follow the tutorials provided on the Eclipse EMF site quite easily.

So, I've been using EMF for a while, and I had a problem with how the data was peristed using the default XMIResourceFactoryImpl. It's good, it works on saving and on loading, but I needed to pass the XML to another device.
The default implemtentation stores each object as an XML element, but each attribute for the object is an XML attribute.
I can't really disagree with that way of doing things, but it didn't suit my needs.

I found this tutorial ( Persisting EMF Models with WTP ) that describes in detail what I needed to do, but I'd like to break it down into a few points in this post here (more for my own records than anything!).
The tutorial tells you which plugins are required - if it's missing any post a comment to this post and I'll list the plugins I had to use.

• Normally when saving, you use
  
  ResourceSet resourceSet = new ResourceSetImpl();
  resourceSet.getResourceFactoryRegistry().getExtensionToFactoryMap().put(
  Resource.Factory.Registry.DEFAULT_EXTENSION, new XMIResourceFactoryImpl());
  
• This default XMLResourceFactoryImpl should get replaced with your own ResourceFactory extending TranslatorResourceFactory
  

resourceSet.getResourceFactoryRegistry().getExtensionToFactoryMap().put(
Resource.Factory.Registry.DEFAULT_EXTENSION, new MyResourceFactoryImpl());

In "MyResourceFactoryImpl" the createResource method must be overridden, using your own TranslatorResourceImpl, which we'll call MyResourceImpl for this tutorial.

Provide an XMLMapping class to provide constants of the XML element/attribute names you wish to use in the outputted XML.
The getDoctype method in MyResourceImpl should refer to a root element definition.
Most importantly, you'll need to create a translator that is returned in the getRootTranslator method. This is covered more in the next step.

MyTranslator should extend RootTranslator. The constructor will have to pass through the mapping name of the root element, along with the root EClass that is to be used.

MyTranslator needs to provide a getChildren method which in turn creates an array of Translator. The translators then get created along the levels, the first level being the creation of translators for the root element, and then for each element underneath.
The example in the tutorial above describes this quite well.

That should cover all you need to know. The Eclipse tutorial linked above really does provide everything you need, this post just condenses it into a few points.