How To Fix BSP_WD028 - Redefinition of method GET_MAIN_ENTITY is missing in controller class &1

SAP Error Message - Details

• Message type: E = Error

• Message class: BSP_WD -

• Message number: 028

• Message text: Redefinition of method GET_MAIN_ENTITY is missing in controller class &1

What causes this issue?

Redefinition of method IF_BSP_WD_HISTORY_STATE_DESCR~GET_MAIN_ENTITY()
is missing in
the reported controller class &V1&.

System Response

Method IF_BSP_WD_HISTORY_STATE_DESCR~GET_MAIN_ENTITY() for base class
CL_BSP_WD_VIEW_CONTROLLER was not redefined as expected.
The interface is also used by extensibility tools to provide correct
object embedding. One should
select for the appropriate main entity, if known.

How to fix this error?

Inform the responsible application developer.

Procedure for System Administrators

Redefine the method IF_BSP_WD_HISTORY_STATE_DESCR~GET_MAIN_ENTITY() in
class &V1&.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message BSP_WD028 - Redefinition of method GET_MAIN_ENTITY is missing in controller class &1 ?

  The SAP error message BSP_WD028 indicates that there is a problem with the method GET_MAIN_ENTITY in a Web Dynpro ABAP application. Specifically, it suggests that the method is expected to be redefined in the controller class, but it is missing. This typically occurs when you are working with a component that is based on a parent component or when you are trying to override a method in a subclass.
  Cause:
  
  Inheritance Issue: The method GET_MAIN_ENTITY is defined in a parent class or interface, and the subclass (your controller class) is expected to provide its own implementation of this method.
  Missing Implementation: The method has not been implemented in the subclass, which leads to this error when the framework tries to call it.
  Incorrect Class Assignment: The controller class may not be correctly assigned or may not be extending the correct parent class.
  
  Solution:
  
  
  Implement the Method: 
  
  Open the controller class that is generating the error.
  Check if the method GET_MAIN_ENTITY is defined in the parent class or interface.
  If it is, implement the method in your controller class. The method signature should match the one in the parent class.
  
  Example:
  METHOD if_my_interface~get_main_entity.
    " Your implementation here
  ENDMETHOD.
  
  
  Check Inheritance:
  
  Ensure that your controller class is correctly inheriting from the appropriate parent class that contains the GET_MAIN_ENTITY method.
  If you are using a component with a specific structure, ensure that your controller is set up correctly in the component configuration.
  
  
  
  Review Component Configuration:
  
  Go to the Web Dynpro component configuration and ensure that the controller is correctly assigned to the view and that the method is expected to be overridden.
  
  
  
  Check for Typos: 
  
  Ensure that there are no typos in the method name or signature. The method name must match exactly with the one defined in the parent class.
  
  
  
  Rebuild the Component: 
  
  Sometimes, rebuilding the component or refreshing the object can resolve issues related to method definitions.
  
  
  
  Related Information:
  
  Web Dynpro ABAP Documentation: Review the official SAP documentation for Web Dynpro ABAP to understand the lifecycle of components and the role of controller methods.
  Debugging: Use the debugger to trace where the method is being called and to confirm that the correct controller is being used.
  SAP Notes: Check for any relevant SAP Notes that might address known issues with specific versions of Web Dynpro or related components.
  
  By following these steps, you should be able to resolve the BSP_WD028 error and ensure that your Web Dynpro application functions correctly.