How To Fix OO_SOURCE_BASED013 - The category of a class can only be changed if there are no sub classes

SAP Error Message - Details

• Message type: E = Error

• Message class: OO_SOURCE_BASED - WB - Class Builder - Messages for the source-b. Class Editor

• Message number: 013

• Message text: The category of a class can only be changed if there are no sub classes

What causes this issue?

You tried to change the class category (standard class, exception class)
by changing the super class. The category of a class can only be changed
if there are no sub classes.

System Response

The system does not save changes made in the class to avoid
inconsistencies in the sub classes.

How to fix this error?

Set a super class that has the same category than your own class.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message OO_SOURCE_BASED013 - The category of a class can only be changed if there are no sub classes ?

  The SAP error message OO_SOURCE_BASED013 indicates that you are trying to change the category of a class in the ABAP Object-Oriented programming environment, but the class has subclasses. In SAP, classes can be categorized as either "abstract," "final," or "normal." Changing the category of a class that has subclasses is not allowed because it could lead to inconsistencies in the inheritance structure.
  Cause:
  The error occurs when:
  
  You attempt to change the category of a class (e.g., from "normal" to "abstract" or "final") while there are existing subclasses that inherit from it.
  The system enforces this rule to maintain the integrity of the class hierarchy.
  
  Solution:
  To resolve this error, you can follow these steps:
  
  
  Identify Subclasses: Check if there are any subclasses that inherit from the class you are trying to modify. You can do this by navigating to the class in the ABAP Workbench (SE80) and looking for subclasses.
  
  
  Remove Subclasses: If you need to change the category of the class, you will have to remove or modify the subclasses that depend on it. This can involve:
  
  Deleting the subclasses (if they are no longer needed).
  Changing the inheritance of the subclasses to another class (if applicable).
  
  
  
  Change the Class Category: Once there are no subclasses inheriting from the class, you can proceed to change the category of the class as needed.
  
  
  Recreate Subclasses (if necessary): If you had to delete subclasses, you may need to recreate them after changing the category of the parent class, ensuring they align with the new class structure.
  
  
  Related Information:
  
  
  Class Categories:
  
  Normal Class: A standard class that can be instantiated.
  Abstract Class: A class that cannot be instantiated and is meant to be a base for other classes.
  Final Class: A class that cannot be subclassed.
  
  
  
  Class Hierarchy: Understanding the class hierarchy and how inheritance works in ABAP is crucial for managing class categories effectively.
  
  
  Documentation: Refer to the SAP Help Portal or the ABAP documentation for more details on class categories and object-oriented programming in ABAP.
  
  
  Best Practices: When designing class hierarchies, consider the implications of changing class categories and plan your class structure accordingly to avoid such issues in the future.
  
  
  By following these steps, you should be able to resolve the OO_SOURCE_BASED013 error and successfully change the category of your class.