how to declare a fully typed field-symbol based on TYPE REF TO DATA parameter ?

[Rodrigo-Giner]

Hi Folks, this is driving me crazy, can someone enlight me.

I have this code

Definition

Class-Methods: validate_data IMPORTING t_data TYPE REF TO DATA.

Implementation

METHOD validate.
  TYPES: type_ztabname TYPE TABLE OF ztabname.
  FIELD-SYMBOLS: <fully_typed_table> TYPE type_ztabname.
  ASSIGN t_data->* TO <fully_typed_table>.
* then it uses <fully_typed_table>-fieldname because the field-symbol is fully typed
* validations
ENDMETHOD.

This is in a class with lots of method just like this one (one for each table they want to validate)

I want to change it and make it better creating a subclass for each table than inherit from an Asbtract class where I pass the table name to the constructor and in each method I can deal with the data without having to repeat the table again .

The problem is that I can't find a way to have a fully type <fs_table> in the method without defineing the type in the same scope. I know the tablename (I pass it to the constructor) I don't want in each method declare the type with again the same table name. But also I need the <fully_typed_table> to be fully typed. I cant change all the <fully_typed_table>-fieldname.

FIELD-SYMBOLS: <fully_typed_table> TYPE (me->table_type). "me->table_type = 'ZTABNAME' 

Is there a way to do this ?

Thanks

[Sandra_Rossi]

First of all, sorry, but your <fully_typed_table> is not fully typed !

A table type fully typed (i.e. not generic) has to have a table category and a key. Example:

TYPES: type_ztabname TYPE STANDARD TABLE OF ztabname WITH EMPTY KEY.

With a type fully typed, you may create a typed data reference:

DATA ref_table TYPE REF TO type_ztabname.

And it's easier to work with:

METHOD validate.
  ref_table ?= t_data.
  LOOP AT ref_table->* REFERENCE INTO DATA(ref_line).
    DATA(fieldname) = ref_line->fieldname.
  ENDLOOP. 
ENDMETHOD.

[Rodrigo-Giner]

Hi, sandra.rossi. Yeah you are right, is not fully typed

TYPES: type_ztabname TYPE STANDARD TABLE OF ztabname WITH EMPTY KEY.

What I was trying to ask is if there is a way to replace the bold part with the content of a variable, but now I realice that is just stupid because even if that would be possible the compiler would never know the structure until runtime so the use of <fs>-fieldname or ref_line->fieldname is impossible.

I just got burnout, my bad. nvm

[Sandra_Rossi]

Thanks for the feedback!

Please use the COMMENT button for comments, questions, adding details, replying to OP comment, etc., ANSWER is only to propose a solution, dixit SAP text at the right of the answer area.

[nomssi]

Here is my understanding of your design struggle:

• You have a single validate routine working on data of different types dynamically.
• You want to change it to a number of data types (classes) each overriding the method validate, i.e. many implementations of the same method.

I do not agree that this transformation makes it better. It depends on the context. Actually the first solution is canonical ABAP.

The second solution is easier in a functional language (like javascript) where you would pass a first class function to the validate method. In ABAP OO, I would suggest using an interface (strategy pattern) instead of your proposed subclassing (template pattern). It will be verbose as you have to objectify (create a class for <fully_typed_table>) and use at least a factory method to inject the object) instead of using dynamic data references.

my 2 cents

JNN