Convert dynamic REF TO DATA structure to static

Question

I created structure with three components, one of which is type ref to data and a table type of this structure. The problem is, how do I add data to this table?

It always has three components, but only one of them is discovered during processing, I always know two of them. Thus I always use the entire table type ref to data and then determine the type of this structure and create the table on it.

The issue here is that by doing this, even though I know two of the components, the whole itab will be dynamic, so I must use it in methods exporting/importing a type ref to data, which is inconvenient.

The method below will always return a table type ref to data, which is completely dynamic (type ref to data), but the structure of the table will always be like this:

component 1 -> type pc261.
component 2 -> type pay99_international.
compoment 3 -> well this is always a mistery hehe

methods get_payroll
   importing it_rgdir        type hrpy_tt_rgdir
   returning value(rt_value) type ref to data.

method get_payroll.
   field-symbols: <lt_payroll> type standard table.
   create data rt_value type standard table of (mv_py_struct_type).
   assign rt_value->* to <lt_payroll>.
   ...
endmethod.

My intention was to have the returning value with another type, a known type, with which I can use the two known components more easily. The idea I had was to create a type with only the unknown field as ref to data, than have a table of it.

This way, I would be able to use it inside methods without having to work so "dynamicaly", which altough works perfectly, is kind of difficult to understand only by reading the code.

types begin of gty_s_generic_payroll.
   types evp   type pc261.
   types inter type pay99_international.
   types nat   type ref to data.
   types end of gty_s_generic_payroll.

types gty_t_generic_payroll type table of gty_s_generic_payroll.

The problem is, how to use an itab of type gty_t_generic_payroll as declared above?

I must somehow create the component 3, but I have no idea how to do it...

At the end, I have a generic field-symbol, that is type table, that has the two known components + the third one that was discovered during processing time.

So how can I pass the content of this field symbol to a table type gty_t_generic_payroll?

data lt_payroll            type ref to data.
field-symbols <lt_payroll> type any table.
lt_payroll = mo_payroll->get_payroll( lt_rgdir ). "this will return type ref to data
assign lt_payroll->* to <lt_payroll>.

After executing this code <lt_payroll> has all the values, but it is a dynamic table where I cannot use components <lt_payroll>[1]-inter.

So how to pass to gty_t_generic_payroll-typed variable, so that I can access components without much dynamics?

Why do you define your field-symbol <lt_payroll> of type any table instead of with type gty_t_generic_payroll? If the only dynamics of your field is in the third component of the row structure, you can access to the components as you intended, with <lt_payroll>[1]-inter and so on. You can even access component nat, but it is of type ref to data of course. You'll have to derefence and assign it in order to access it. — rplantiko
You say "how do I use an itab of type gty_t_generic_payroll" but I don't understand where is your difficulty. Can you show a code snippet to illustrate how you'd like to use it? — Sandra Rossi
Hello, rplantiko, I must use that field symbol as any table because the values I take come from a standard function module that only accepts internal tables as exporting parameters. This way, <lt_payroll> is considered a internal table and the function module works — Pedro Accorsi
Hello, Sandra, the problem with using the whole table as dynamic is that it must be used in a lot of other methods as dynamic. This means I must create a bunch of field symbols assigning components from the table, cannot loop using where, even read table must be done dynamicaly, which at the end makes the code less readable, altough fully working. Now, with this new table not-so-dynamic, whomever tries to read the code, will understand it at first glance, to support, who debug all day, it is extremely helpful :D — Pedro Accorsi

Florian Florian · Accepted Answer · 2019-04-03T13:53:13

Given your target structure and table like this:

TYPES:
  BEGIN OF payroll_row_type,
    known_first_component  TYPE something_we_know,
    known_second_component TYPE something_else_we_know,
    discovered_component   TYPE REF TO data,
  END OF payroll_row_type.

TYPES payroll_table_type TYPE STANDARD TABLE OF payroll_row WITH EMPTY KEY.

If you now have another table, whose type at runtime is:

TYPES:
  BEGIN OF discovered_row_type,
    known_first_component  TYPE something_we_know,
    known_second_component TYPE something_else_we_know,
    known_third_component  TYPE some_data_type,
  END OF discovered_row_type.

TYPES discovered_table_type TYPE STANDARD TABLE OF discovered_row WITH EMPTY KEY.

You can move one to the other with

DATA source TYPE discovered_table_type.
DATA target TYPE payroll_table_type.
DATA resolved_component TYPE REF TO DATA.

DATA(descriptor) = 
  cl_abap_elemdescr=>describe_by_data( source_row-known_third_component ).

LOOP AT source INTO DATA(source_row).

  DATA(target_row) =
    VALUE payroll_row_type(
      known_first_component  = source_row-known_first_component
      known_second_component = source_row-known_second_component ).

  CREATE DATA target_row-discovered_component TYPE descriptor.
  ASSIGN source_row-known_third_component TO FIELD-SYMBOL(<source_component>).
  ASSIGN target_row-discovered_component TO FIELD-SYMBOL(<target_component>).
  <target_component> = <source_component>.

  INSERT target_row INTO TABLE target.

ENDLOOP.

Convert dynamic REF TO DATA structure to static

3 Answers