1. A method, in a data processing system, for defining a controller layer of an application using a model-view-controller architecture, comprising: separating a controller layer of the model-view-controller architecture into a plurality of controller overlays; providing an editor for each of the plurality of controller overlays through which controllers for each of the plurality of controller overlays are defined; and combining the controllers in each of the plurality of controller overlays into a complete controller specification for model-view-controller architecture of the application.