The Model View Controller Paradigm 

Definition

The model view controller paradigm (MVC paradigm) is based on a clear separation of the functions of data model (model), presentation logic (view), and program control (controller).

In Web Dynpro, the function of the model has been extended beyond a mere persistency layer. In a Web Dynpro model, you can encapsulate functions that represent an entire business process.

Model

The Web Dynpro developer can define a model for retrieving data as well as for integrating business logic.

View

The view is responsible for the graphic display of the data. Within Web Dynpro, the view element of the MVC paradigm is represented by the logical units view set and view and the UI elements contained in them. View designers always work with logical interface objects, although they can also access the Java source text directly, for example to generate the UI automatically and to have additional coding run at runtime. 

Controller

The controller is responsible for the program control. It controls the flow of data between view and model and handles events.

In Web Dynpro, the role of the controller is divided among several controllers:

·        View controllers that are directly assigned to a view,

·        A component controller as the central instance to which you can add other custom controllers,

·        An interface controller that makes its data available to a higher-level component.