Event Handler 
Event Handler
Event handlers allow the separation of static and dynamic code in a page. The layout processing deals with the static data, while the event handlers deal with the dynamic data.
The following predefined event handlers are available in the SAP system:
|
Event Handler |
Description |
| OnCreate |
OnCreate is called once when the page is first created (stateful mode), and performs a once-off data initialization or object creation. |
| OnRequest |
OnRequest is called whenever a request is made for a particular page and is used to restore the internal data structures from the request. This is important when working in stateless mode. |
| OnInitialization |
This event handler is mainly used for data retrieval. For example, it allows data required for displaying the BSP to be read from the database. It can also execute any program. |
| OnInputProcessing |
This event handler checks and processes user input. It can also define navigation, that is, whether the user should be taken to the same page or another when the BSP is called. |
| OnManipulation |
You can use this event handler to manipulate the HTTP data stream later. |
| OnDestroy |
This event handler is available for special functions. |
The ABAP syntax checks that apply in the context of ABAP Objects also apply to event handlers.
Read and modify access to page attributes is available in all handlers. Global objects are also available.
Global objects and their signatures for individual event handlers are displayed if you choose 
in the Web Application Builder.
The use of the individual event handlers is explained in more detail in the individual sections of the documentation.
See also:
Control Flow of BSPs