Modeling a Web Dynpro Application
(Java)
Purpose
The logical interface unit Web Dynpro model is provided for the data retrieval in a Web Dynpro application. As there are various types of models, there are many possibilities for connecting to an existing back end. There is a model type for the use of local or external Web services (Web service model), a model type that can create a connection to an SAP system (Adaptive RFC model), a model for importing JavaBean classes (JavaBean model), and a model for importing UML descriptions. Furthermore, a corresponding model type exists for integrating data from the Exchange Infrastructure (XI) to support the Enterprise Services Architecture (ESA). As the SAP NW Developer Studio uses tool sets for developing Web Dynpro applications as well as JavaBeans, it is possible for a single developer to carry out the development of the entire application, including the user interface, application logic, and back-end data. Additionally, more than one model can be defined for the application at design time. After that, the valid model for the running application can be determined using the model usage.
Use of the Process
This process is part of the following IT scenario:
IT Scenario |
Scenario Variant |
Prerequisites
You want to develop user interfaces using Web Dynpro Java technology.
Process Flow
1. Structuring the Web Dynpro Project and Arranging It into Components
To develop a development component (DC) of type Web Dynpro for a subsequent versioning of the application in the SAP NetWeaver Java Development Infrastructure (NWDI), only the definition of the respective Web Dynpro project type is necessary. In doing so, a container for the development objects and resources is defined. The DC concept additionally offers the opportunity to structure complex Web Dynpro applications and to divide them into smaller application parts. A further central advantage is the option to support application development across team boundaries. A software component (SC) merges the DCs into larger units for the deployment. A mutual usage relation can exist between SCs. As an SC does not contain any development objects, it exclusively defines the dependencies of those components that are assigned to it. During the planning phase, the Web Dynpro application developer assigns task-oriented application objects such as views (an example of this could be a view with a search or display function) to individual DCs and names them correspondingly. At design time, only a few steps are required to create the objects for a DC explicitly.
2. Creating Reusable Web Dynpro Components
The Web Dynpro programming model allows a clear separation of the three software layers presentation logic, process logic and data collection thanks to the Model View Controller (MVC) concept. This achieves a high degree of reutilization. In addition, a high degree of reutilization of programs or program parts accelerates the development process in the project teams. The maintenance of Web Dynpro applications that use the NWDI and are versioned in the Design Time Repository, is extremely simplified by the use and modeling of Web Dynpro components. The arrangement of a Web Dynpro application into component offers even more advantages; entire application parts can be nested, for example.
3. Modeling End User Navigation
The graphic tool Navigation Modeler offers support at design time for user navigation at runtime. The UI designer can define the interface units, determine their position on the screen, and define the sequence of the view output in a pre-configured view set. These settings can be changed later if necessary. This also applies to the newly assigned navigation links. The view composition can be defined as desired for there is no restriction concerning the integration of views in respect to their quantity. The link then identifies the valid view at runtime.
4. Modeling Portal Navigation
SAP Enterprise Portal and Web Dynpro for Java are the strategic SAP NetWeaver technologies for developing user interfaces. Both are an integral part of the Java technology stack, both run on the SAP Web Application Server and are therefore closely linked with each other. If Web Dynpro application developers make their applications available in the SAP portal, that is, they have them integrated by the Portal administrator, they can make the navigation functions that are offered by the portal available to end users. An appropriate navigation between the portal applications saves time and increases the user’s productivity. Object-based navigation (OBN) is one of these portal functions: It allows access to a portal application that is based on a specific back-end business object. It also allows real-time information to be maintained about this object relating to the role of the user.
Result
An application model now exists as a paper version or in an online modeling tool including all navigation aspects.