Transition from Initial Screen to Maintenance Screen

Use

The system navigates from the initial screen to the maintenance screen when one of the following activities is performed:

  • The user presses the Enter key

  • In background processing, an equivalent functionality (equivalent to pressing the Enter key) is induced

The entire flow is controlled in function group BRF_MAINTENANCE by sub-program NORMAL_COMMAND_1005 in branch 'CONT' of the CASE statement. The following steps are executed and/or the following methods called:

  1. Check at PAI

    The PAI_ENTRY method is called.

    If the system finds an error during this check, it outputs a message (such as error message 'Object not found') and remains on the initial screen.

  2. If the system does not find any errors during this check, the GET_SCREEN_STATE method is called.

    It must be stated that this method no longer has any significance. It is mentioned here for the sake of completeness.

  3. Call of the GET_MNT_INSTANCE method

    This method has the following tasks:

    • It determines the concrete class (in this case CL_VALUE_REQUEST_TABLE_MNT_BRF).

    • It creates an instance of this concrete class. This instance is used for further maintenance.

      The GET_MNT_INSTANCE method is necessary because the concrete class is not yet known on the initial screen, meaning that only the methods of the base class can be used.

  4. Relevant methods with new expression type

    When the instance of the concrete class has been created, the methods that you must partially redefine become relevant.

Relevant Methods (that you must partially redefine)

The relevant methods are described below, taking class CL_VALUE_REQUEST_TABLE_MNT_BRF as an example. This class enables access to a field of a line of an internal table (expression type Field of a Line of an Internal Table (implementing class 0TB001)).

The line is determined similarly to the ABAP statement SELECT, whereby the WHERE condition is saved in table TBRF144.

Other characteristics that specify the object are located in table TBRF142. There are member structures for table TBRF142 and member tables for table TBRF144.

The following methods are relevant if you have developed a new expression type: