Why does EMF need a GenModel as well as an Ecore model to generate code?
The GenModel is a decorator model for the Ecore model. It specifies information not available in the Ecore model and gives fine grained control over what’s generated. For example, the Ecore model doesn’t indicate where the code should be generated and what the plugin ID (if any) for that target should be; that’s specified in the GenModel. The GenModel also lets you choose among various generation patterns. For example, do you want root interfaces to extend EObject, nothing, or something of your own choosing? And do you want to generate an editor that targets the Eclipse Rich Client Platform versus the Eclipse Integrated Development Environment? So you can think of the GenModel as a giant parameter for controlling and tailoring the code generation process.
