Web Dynpro for Java
Use
Web Dynpro for Java (WDJ) is a client-independent programming model for creating complex user interfaces. In comparison to the Visual Composer, you can also create user interface (UI) elements dynamically and you have full control over every UI element.
The key features of WDJ include:
· Several connectors to the business logic layer:
¡ Web services
¡ Composite Application Framework (CAF) Application Services
¡ BAPIs
¡ RFCs
● An infrastructure fully integrated in SAP NetWeaver Developer Studio and the NWDI software lifecycle
● Integration with Guided Procedures
● Dynamic UI element generation
● Clear separation of UI layer and business logic layer (using only RFCs and Web services)
● Personalization of views
Due tothe lower degree of model-driven UI development, the WDJ requires developer skills.
General Guidelines
The WDJ is used to define the UI. Therefore:
● No business logic or object persistence should be implemented within Web Dynpro Java components.
● Use coding only to call Web services and create and handle the user interface.
As a result, the WDJ application contains the WDJ model to access the Web service, context mapping from the model nodes to the corresponding component (view) nodes, and the views created with the WDJ design time. Dynamic modification of the views is also allowed.
Back-End Connectivity
You should use enterprise SOA Web services to access the back end.
Business Layer Connectivity
For a flexible composite architecture, use Web services to connect the UI layer to the business logic layer. Therefore, the business layer has to expose all relevant application services as standard Web services on the SAP NetWeaver Composition Environment server.
For example, you can connect the WDJ component and the business logic layer using Web services provided by CAF.
Another possibility to connect to the business layer is the EJB 3.0 importer. With this importer, you can access the business logic in an EJB 3.0 session bean.
More information: Composite Application
Framework,
Integrating EJB 3.0 into Web
Dynpro
Process Layer Integration
The process layer uses Guided Procedures (GP) as the process framework. A WDJ component can be included in a GP process when it implements the callable object WDJ interface (com.sap.caf.eu.gp.co.api.IWebDynproCO) provided by GP.
More information:
Implementing Web Dynpro Callable
Objects
Customizing (Personalization)
WDJ offers implicit personalization. This feature is handled by the WDJ runtime so no additional programming is needed to modify views. The administrator or user can change labels, remove UI elements, disable UI elements, and add certain action-free UI elements like text boxes and labels.
More Information