Get class Instance, and then get hers attributes

[former_member998879]

Hi Gurus,

i'm new to ABAP Object,

creating an a BSP whit MVC controller i've try to implement the class controller,

but on a method of it i want to get instance of the class parents:

the class that i implement is an extension of CL_BSP_CONTROLLER2.

In this class in the method DO_REQUEST ( for example ) i try to get the instance of the class

parent ( and i got it! ) using this syntax:

  data: Parent type ref to IF_BSP_DISPATCHER,   " type take from attribute M_PARENT of the class
  
 Parent = ME->M_PARENT.

In debug i see that 'Parent' get rightly the class parent instance but than i want do this:

(i want get the sub controller of the main contoller 'parent', in debug i can see everything fine)

   SubController = Parent->GET_ATTRIBUTE(LEFT_CONTROLLER).

But the compiler say that the class instance 'Parent' has no methods and no attribute.

i've try other syntax like:

    call METHOD Parent_>GET_ATTRIBUTE
        IMPORTING
     LEFT_CONTROLLER)

  call METHOD ME->M_PARENT->GET_CONTROLLER
   EXPORTING
     CONTROLLER_ID = 'search'
   IMPORTING
     CONTROLLER_INSTANCE = Parent2

No one work!

How can i do?

Here screnshot of that i see in debug mode, and that i want get:

http://img190.imageshack.us/i/1debugscreen.jpg/

http://img10.imageshack.us/i/2debugscreen.jpg/

Thanks in advance,

Davide

[Pawan_Kesari]

The parent of CL_BSP_CONTROLLER2 is of type IF_BSP_DISPATCHER.

And IF_BSP_DISPATCHER definitely doesn't have any property LEFT_CONTROLLER. So I think you are looking at the wrong place.

Access LEFT_CONTROLLER attribute of class ZGEO_CONTROLLER_MAIN. I think instance of ZGEO_CONTROLLER_MAIN is available in program.

Edited by: Pawan Kesari on Jul 3, 2009 4:03 PM

[former_member998879]

Hi Pawan,

classes ref to CL_BSP_CONTROLLER2 like my controller class, have an attribute

M_PARENT type IF_BSP_DISPATCHER.

If the class is a subclass of an main class it has the M_PARENT attribute containing the instance of the parent class,

i can see in debug mode ( here example: http://img40.imageshack.us/img40/1648/3debugscreen.jpg )

i can get this attribute:

  data: Parent type ref to IF_BSP_DISPATCHER,   " type take from attribute M_PARENT of the class
  
 Parent = ME->M_PARENT.

but the interface IF_BSP_DISPATCHER has no attribute and no method defined, and if i declare 'Parent' as type ref to

CL_BSP_CONTROLLER2 the compiler return error

<=> "The type of "PARENT" cannot be converted to the type of "ME->M_PARENT". "

Davide

[Pawan_Kesari]

From screen it appear that M_PARENT attribute has instance of class ZGEO_CONTROLLER_MAIN.

I wonder if you could just do it this way

data: Parent type ref to ZGEO_CONTROLLER_MAIN.
Parent = ME->M_PARENT .

[uwe_schieferstein]

Hello Davide

Without knowing the relation between the classes (hierarchy, interfaces) it is difficult to understand your problem.

Assuming that your left controller always is an instance of class ZGEO_CONTROLLER_SEARCH (assumption: implements interface IF_BSP_DISPATCHER) you could try the following:

data: 
  Parent type ref to IF_BSP_DISPATCHER,   " type take from attribute M_PARENT of the class
  lo_left_controller        TYPE REF TO zgeo_controller_search.


 Parent = ME->M_PARENT.

lo_left_controller ?= parent.

CALL METHOD lo_left_controller->...

Regards

Uwe

[former_member998879]

type ZGEO_CONTROLLER_MAIN is a type ref to CL_BSP_CONTROLLER2, and just i say above do:

data: Parent type ref to ZGEO_CONTROLLER_MAIN.
Parent = ME->M_PARENT .

doesn't work. "The type of "PARENT" cannot be converted to the type of "ME->M_PARENT"."

Thanks however for you help!

Davide

[former_member998879]

Thanks Uwe,

but does not work.

Compiler say everything ok, but error occured when executing the instruction

  lo_left_controller ?= parent.

Davide

[uwe_schieferstein]

Hello Davide

There must be a simple way using casting but - as I said already - without knowing the relations and interfaces of the classes it is difficult to find the solution.

Alternatively, you may call the method dynamically.

data: 
  Parent type ref to IF_BSP_DISPATCHER,   " type take from attribute M_PARENT of the class
  lo_obj        TYPE REF TO object,   " root class
 ld_method  TYPE string.
 
 Parent = ME->M_PARENT.
 
lo_obj ?= parent.

ld_method = '<name of public method>'.
 
CALL METHOD lo_obj->(ld_method)...

Regards

Uwe