Web Dynpro: Abstraction and Rendering
(Third article of the series: Web Dynpro) The web dynpro framework (WDF) allows for building an abstract description of the application. This description is abstract as it is not programming language dependent and just has information about the application – the metadata. The metadata is stored in XML format.
This metadata code is generated automatically by the framework once the application is built. Naturally it is recognized by and conforms to standards of WDF.
The meta model of the application doesn't have any code from back-end implementation. It is also free of front-end technologies and does not have any HTML or Java Script code.
The following sketch captures the essentials of the web dynpro framework along with its different components:
|Web Dynpro Framework|
The developer doesn't need to write any html code to present it to the client (internet browser, etc.) and doesn't need to make it interactive by writing java script code. Here lies the biggest advantage. The manual writing of client-specific coding is eliminated. The rendering engine web dynpro framework takes care of generating the required code in HTML and Java script to present it on user's client and device.
SAP has developed different rendering engines. It has Classic rendering engine for HTML browsers and time-to-time updated for extending support to many internet browsers. Then there is Light-speed rendering engine which has more fine-tuned HTML and Java-script rendering to enhance performance and to include support for AJAX. There is rendering engine for SAP Netweaver Business Client which uses rich content like charts, advanced graphics and presentation of advanced analytics.
As can be seen, for making the application available to a new client doesn't require to write the application itself. The business application will be the same without modification. It's only the rendering engine which will be updated or new one offered.
SAP aims at making the web dynpro UI technology future-proof. As the client UI technology is advancing very fast, there may be new technologies on the horizon. If the market needs and dynamics force SAP to adopt to a new UI technology, it is confident of doing so through enhancing an already existing or developing a new rendering engine.