Technical principles for programming SAP Internet applications By Mario Perez, Alexander Hildenbrand, Bernd Matzke,...
This tip is excerpted from SAP R/3 on the Internet, published Addison Wesley.
Users cannot call the SAP System directly from the Web server. The type and method of data exchange between the Web server and external programs represent one reason for this inability. Instead of a direct call, the Web server starts a program that connects it to the R/3 System. This method uses the screen interface of the SAP System as the technical transmission channel. The R/3 System and the front end designated as the SAPGUI communicate with each other over this interface. To the R/3 System, the coupling program behaves similarly to a normal SAPGUI. It converts screen data from the SAP System into HTML documents and vice versa. In the process, HTML templates serve as models the following advantages for the Web pages created by the system. This approach provides a simple way to make ABAP/4 applications capable of use on the Internet. The approach offers the following advantages:
- Development and testing of the Internet applicaion can take place almost completely in the R/3 System.
- Connections use only proven interfaces of the R/3 System.
- The various components of the Internet applications can operate with the Correction and Transport System of the R/3 SYstem without any difficulties. This feature enables a simple way to upgrade the standard Internet Application Components (IACs) delivered by SAP. Just as they do with other applications, customers can develop Internet applications in a test system and then transport them into the production system.
- The R/3 System can store all the components of an application, even when the applications must operate externally at runtime.
- To generate language-independent HTML documents, the Internet applications can use the automatic language features of the SAP System.
We must strongly emphasize, however, that developers must optimize the application running in the R/3 System to meet the demands of the Web. Although web-capable R/3 applications can run in the R/3 System and, independently of the Web, undergo testing there, they do not meet the demands made on pure R/3 applications. The procedures chosen by SAP enable development of Internet-capable R/3 applications. It remains impossible, however, for any existing R/3 application to run on the Web without any modifications. Web applications aim at a different group of users than do applciations that operate over the normal SAPGUI. Accordingly, new development must occur in any case, and thus represents no real handicap.
Although the coupling program is complex, it remains a completely transparent application to developers and to users. In addition to its obvious tasks, exchangeing data between the Web and the R/3 System and converting screen and HTML documents into each other (in both directions), the program must perform additional, system-oriented tasks. These tasks include the administration of various Web users, system resources, and various Internet applications in addition to the maintenance of security standards. The Internet Transaction Server (ITS) performs all these tasks.
To learn more about Sap R/3 on the Internet, click here.