How to get the parent of cl_gui_html_viewer object?

[Former Member]

Hey all,

I want to get the parent of my  cl_gui_html_viewer object. When I debug it I can clearly see that its parent type is a reference to   cl_gui_simple_container but when I write the following code:

DATA: lo_simple_container TYPE REF TO cl_gui_simple_container.

lo_simple_container = lo_html_header->parent.

and want to active it. It gives me the following error:

The type of ''LO_HTML_HEADER->PARENT'' cannot be converted to the type of ''LO_SIMPLE_CONTAINER''

but why if I am using the right reference type? Can somebody tell me how can I get the parent of my object lo_html_header?
Thank you.

Regards,
RB

[Sandra_Rossi]

This is a question of up and down casting (or widening/narrowing cast respectively).

You must use one of the two variants :

• up casting : more_general = less_general.
• down casting : less_general ?= more_general

In your case, you have:

• <ref to cl_gui_simple_container> = <ref to cl_gui_container>, i.e. it's down casting

So you must use:

• lo_simple_container ?= lo_html_header->parent.

ABAP documentation : http://help.sap.com/abapdocu_702/en/?url=ABENCAST_CASTING_GLOSRY.htm