topic Re: Dynamic interface declaration in Application Development and Automation Discussions

Dynamic interface declaration

Former Member — Mon, 16 Nov 2009 13:45:20 GMT

Hello,

Is it possible to have a dynamic interface declaration like you can have a dynamic object declaration?

For an object:

data: lo_object type ref to object.

create object lo_object type (lv_object_name).

Is this in some way possible to do with an interface? I need to do this for an interface at runtime.

Gr,

Jaron

Re: Dynamic interface declaration

matt — Mon, 16 Nov 2009 14:23:24 GMT

As long as lv_object_name contains the name of an interface that exists, then the syntax is valid.

matt

Re: Dynamic interface declaration

Former Member — Mon, 16 Nov 2009 14:26:11 GMT

I get an error message saying I can't do it because it's not a class.

Edited by: J. Frenk on Nov 16, 2009 3:26 PM

Re: Dynamic interface declaration

matt — Mon, 16 Nov 2009 15:10:14 GMT

oops. my bad.

Yes, of course you'll get that error. Because you can't create an object reference to an interface. It has to be reference to a concrete class.

Are you wanting something like:

DATA: r_ref TYPE REF TO (my_interface).

where my_interface contains the name of the interface?

matt

Re: Dynamic interface declaration

Former Member — Wed, 18 Nov 2009 08:28:13 GMT

You can create data of a dynamically given reference type (which may be an interface) and move the object reference to it.

Something like so:

DATA:
      my_obj TYPE REF TO object,
      lr_data TYPE REF TO data.

  FIELD-SYMBOLS: <fs> TYPE ANY.

  CREATE OBJECT my_obj TYPE my_object_type.

TRY.
  CREATE DATA lr_data TYPE REF TO (some_interface_type_name).
  ASSIGN lr_data->* TO <fs>.
   <fs> ?= my_obj.

  CATCH cx_sy_move_cast_error.
  CATCH cx_sy_create_data_error.
ENDTRY.

Basically, the assignment tests if my_obj is an instance of the type named some_interface_type_name.

Hope this helps,

Sebastian