Implementing Element Handler Classes

The element handler class is the central class of a BSP element. It implements the specific functions of an element and thus influences the flow logic of the BSP page that uses this element. Through the type of implementation of certain methods belonging to this class, you can control whether and which data is updated in the HTML data stream and whether the content of a BSP element is processed or discarded. Element handler classes are instantiated during the processing of a BSP page and called at defined points in time using certain class methods.

A valid element handler class must implement the interface IF_BSP_ELEMENT. We therefore recommend that you derive this class from the generated superclass (Z)CLG_<EXTENSION>_<ELEMENT> because it already contains the standard implementations for the interface methods.

The flow during implementation of the specific functions of a BSP element is divided up into the following three steps:

1. Creating the attributes for the BSP element See also Defining BSP Elements.

   In this way, you make sure that the new attributes are added as attributes of the element handler classes after activation of the BSP extension.

2. Overwriting certain interface methods of the element handler class

3. Creating further methods or attributes that enhance the element functions