How do I dynamically create objects based on an internal table?

Question

I have an internal table filled with the type reference for the objects I want to create, like so (first line is the header of internal table ITAB):

+==========+===============+
| OBJ_TYPE | OBJ_CLASS_REF |
+==========+===============+
| TYPE1    | ZCL_CLASS1    |
|----------|---------------|
| TYPE2    | ZCL_CLASS2    |
+----------+---------------+

What I would like to do in my program is this (I put line numbers):

1   LOOP AT itab
2    "Concatenate LO_ and the value of ITAB-OBJ_TYPE
3     CONCATENATE 'LO_' itab-obj_type INTO v_obj_name.
4    "Create a reference object
5     CREATE DATA (v_obj_name) TYPE REF TO itab-obj_type.
6     CREATE OBJECT (v_obj_name).
7   ENDLOOP

How do I successfully do lines 5 and 6?

Answer 1

First of all, it's a good idea to provide an interface or an abstract superclass and have your various classes implement that interface or subclass that abstract class - this will save you a lot of unnecessary casting. So let's say you have ZIF_FOO with classes ZCL_BAR and ZCL_BAZ implementing it. The table could be

TYPES: BEGIN OF t_line
         type_name TYPE seoclass,
         instance  TYPE REF TO zif_foo,
       END OF t_line.
DATA: lt_instances TYPE STANDARD TABLE OF t_line,
      ls_instance  TYPE t_line.

Then you can fill the table like this:

ls_instance-type_name = 'ZCL_BAR'. " or wherever you get this value from
CREATE OBJECT ls_instance-instance TYPE (ls_instance-type_name).

If you want to use local classes, you can do the same - just use a longer type name (SEOCLASS with its 30 characters won't be enough) and specify the type name as described in the online documentation of the RTTI:

ls_instance-typename = '\PROGRAM=ZMYREPORT\CLASS=LCL_MYCLASS'.