topic Re: Describe a data element by RTTI in Application Development and Automation Discussions

Describe a data element by RTTI

Former Member — Fri, 19 Oct 2007 13:10:22 GMT

Hello,

I will describe a data element rtti.

With data type I mean:

A data element which i saved in the DDIC with data type DEC and a length of 15 with 4 decimal plases.

This means I will create a method with a importing parameter type "DATA" (or any) and a exporting parameter of type "dfies"

DFIES is the line type of DDFIELDS.

I have implemented already a method for describing a structure.

I have do tihs as following:

- create a method with incoming parameter type any and exporting parameter type ddfields

- call cl_abap_typedesc=>describe_by_data (my structure as imput)

- I receive a reference

- Cast the reference to type cl_abap_structdescr

-call cl_abap_structdescr->get_ddic_field_list

- I receive a list with all values for each attribiute of the structure! It works fine!

Now I want to do the same for only a simple data type:

I have also implemented the call cl_abap_typedesc=>describe_by_data.

But which is the correct casting type for data elements?

I receive also a type cl_abap_structdesc. But after casting I receive a dump because the structue has no fieldlists and so on.

If i use a other type for casting, for example cl_abap_elemdesc I receive the dump by the casting.

How can I get the describtion of a data element by RTTI?

I think the correct way must be by using type cl_abap_elemdesc, because there is a method which returns a structure of the type DFIES, but how must I cast this type?

Thanks for help

Regards

Christian

Re: Describe a data element by RTTI

uwe_schieferstein — Fri, 19 Oct 2007 13:59:47 GMT

Hello Christian

Have a look at the sample report<b> ZUS_SDN_RTTI_ELEMENT</b>.

*&---------------------------------------------------------------------*
*& Report  ZUS_SDN_RTTI_ELEMENT
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  ZUS_SDN_RTTI_ELEMENT.

TABLES: dfies.

DATA:
  gs_dfies        TYPE dfies,
  go_typedescr    TYPE REF TO cl_abap_typedescr,
  go_elemdescr    TYPE REF TO cl_abap_elemdescr.


START-OF-SELECTION.

  go_typedescr = cl_abap_typedescr=>describe_by_data(
    dfies-tabname ).

  go_elemdescr ?= go_typedescr.
  gs_dfies = go_elemdescr->get_ddic_field( ).

  WRITE: / gs_dfies.


END-OF-SELECTION.

Regards

Uwe

Re: Describe a data element by RTTI

Former Member — Tue, 23 Oct 2007 08:52:43 GMT

Thanks a lot for help.

I don't know exactly what I have make wrong but it works, now.