Class hierarchy

[Former Member]

Hi all,

I have a standard class C1 e two custom class Z1 and Z2 with the follow hierarchy scheme:

Z2 derived from Z1 derived from C1.

If I was in a Z2 method, can i call directly a C1 method?

Best regards,

Raffaele

[former_member199581]

Yes, you can.

It's fundamental that the C1 method is declared at least as Protected (or Public), which make the method visible to all subclasses.

Hope this helps,

R.

Ciao!

[Former Member]

Sorry, but can you write me an example for the syntax of the call?

Grazie

Raffaele

[former_member199581]

Copy and Paste this:

REPORT  yrobscratch.

*---------------------------------------------------------------------*
*       CLASS c1 DEFINITION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c1 DEFINITION.

  PUBLIC SECTION.

    METHODS: m1.

  PROTECTED SECTION.

    METHODS: m2.

ENDCLASS.                    "c1 DEFINITION

*---------------------------------------------------------------------*
*       CLASS c2  INHERITING FRO
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c2 DEFINITION INHERITING FROM c1.

  PUBLIC SECTION.

    METHODS: m3.

  PRIVATE SECTION.

    METHODS: m4.

ENDCLASS.                    "c2  INHERITING FRO

*---------------------------------------------------------------------*
*       CLASS z1  INHERITING FRO
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS z1 DEFINITION INHERITING FROM c2.

  PUBLIC SECTION.

    METHODS: call_m2.

ENDCLASS.                    "z1  INHERITING FRO

*---------------------------------------------------------------------*
*       CLASS c1 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c1 IMPLEMENTATION.

  METHOD m1.

    WRITE: /'Metodo M1 - Classe C1 - Pubblico'.

  ENDMETHOD.                    "m1

  METHOD m2.

    WRITE: /'Metodo M2 - Classe C1 - Protetto'.

  ENDMETHOD.                    "m2

ENDCLASS.                    "c1 IMPLEMENTATION

*---------------------------------------------------------------------*
*       CLASS c2 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c2 IMPLEMENTATION.

  METHOD m3.

    WRITE: /'Metodo M3 - Classe C2 - Pubblico'.

  ENDMETHOD.                    "m3

  METHOD m4.

    WRITE: /'Metodo M4 - Classe C2 - Privato'.

  ENDMETHOD.                    "m4

ENDCLASS.                    "c2 IMPLEMENTATION

*---------------------------------------------------------------------*
*       CLASS z1 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS z1 IMPLEMENTATION.

  METHOD call_m2.

    WRITE: 'Metodo call_M2 - Classe Z1 - Pubblico - Chiamo il metodo M2 di C1:'.
    me->m2( ).

  ENDMETHOD.                                                "call_m2

ENDCLASS.                    "z1 IMPLEMENTATION


START-OF-SELECTION.

  DATA: theClass TYPE REF TO z1.

  CREATE OBJECT theClass.

  theClass->call_m2( ).

You see that call_M2 method doesn't call a Public method of C1, but a Protected, as I was saying before.

Inside classes you can play with method calls, it will show you the inheritance principle!

Hope this helps,

R.

[Former Member]

Sorry,

but I think I don't explain my problem very well:

I have Z2 derived from Z1 derived from C1.

Now I have a method m1 in C1 which was ridefined in Z1 and ridefined more in Z2.

I'm writing in Z2->m1 method: If Iwant to call the Z1->m1 method, I write the follow instruction:

CALL METHOD super->m1. " -

---

I can do this without any problem.

But If I want to call the C1->m1 method, what is the instruction I have to write, inside Z2->m1?

I hope I explain better, now.

Best Regards

Raffaele.

[former_member199581]

...mmm let me try this and I'll say you something!

[former_member199581]

I think, but I can go wrong, that this simply not possibile until you define a service method that re-distributes the call.

As abap documentation says, ABAP takes over the principle of single inheritance. This means that a subclass can only have ONE superclass.

You can only re-distribute the call, like this:

*---------------------------------------------------------------------*
*       CLASS c1 DEFINITION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c1 DEFINITION.

  PUBLIC SECTION.

    METHODS: m1.

  PROTECTED SECTION.

    METHODS: m2.

ENDCLASS.                    "c1 DEFINITION

*---------------------------------------------------------------------*
*       CLASS c2  INHERITING FRO
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c2 DEFINITION INHERITING FROM c1.

  PUBLIC SECTION.

    METHODS: m1 REDEFINITION.
    METHODS: m3.

  PRIVATE SECTION.

    METHODS: m4.

ENDCLASS.                    "c2  INHERITING FRO

*---------------------------------------------------------------------*
*       CLASS z1  INHERITING FRO
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS z1 DEFINITION INHERITING FROM c2.

  PUBLIC SECTION.

    METHODS: m1 REDEFINITION.

    METHODS: call_m2.

ENDCLASS.                    "z1  INHERITING FRO

*---------------------------------------------------------------------*
*       CLASS c1 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c1 IMPLEMENTATION.

  METHOD m1.

    WRITE: /'Metodo M1 - Classe C1 - Pubblico'.

  ENDMETHOD.                    "m1

  METHOD m2.

    WRITE: /'Metodo M2 - Classe C1 - Protetto'.

  ENDMETHOD.                    "m2

ENDCLASS.                    "c1 IMPLEMENTATION

*---------------------------------------------------------------------*
*       CLASS c2 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS c2 IMPLEMENTATION.

  METHOD m1.

    WRITE: /'Metodo C2->M1 - Ridefinizione di C1->M1'.
* // Calls C1->M1.
    super->m1( ).

  ENDMETHOD.                    "m1

  METHOD m3.

    WRITE: /'Metodo M3 - Classe C2 - Pubblico'.

  ENDMETHOD.                    "m3

  METHOD m4.

    WRITE: /'Metodo M4 - Classe C2 - Privato'.

  ENDMETHOD.                    "m4

ENDCLASS.                    "c2 IMPLEMENTATION

*---------------------------------------------------------------------*
*       CLASS z1 IMPLEMENTATION
*---------------------------------------------------------------------*
*
*---------------------------------------------------------------------*
CLASS z1 IMPLEMENTATION.

  METHOD m1.

    WRITE: /'Metodo Z1->M1 - Ridefinizione di C2->M1'.
* // Calls C2->M1
    super->m1( ).

  ENDMETHOD.                    "m1

  METHOD call_m2.

    WRITE: 'Metodo call_M2 - Classe Z1 - Pubblico - Chiamo il metodo M2 di C1:'.
    me->m2( ).

  ENDMETHOD.                                                "call_m2

ENDCLASS.                    "z1 IMPLEMENTATION


START-OF-SELECTION.

  DATA: theclass TYPE REF TO z1.

  CREATE OBJECT theclass.

  WRITE 'Stack Chiamate'.
  theclass->m1( ).

But you cannot call directly the super.super->m1( ).

However, I'm still investigating!

[Former Member]

Ok thank you very much Roberto,

but I need just the syntax for super.super->m1().

1000 Grazie per la disponibilità comunque!

[former_member199581]

No problem!

Se trovo qualcosa, ti faccio sapere!