Type mismatch when calling cl_salv_bs_runtime_info=>get_data_ref()

I found a solution here which I try to apply.

 cl_salv_bs_runtime_info=>set(
  EXPORTING
    display  = abap_false
    metadata = abap_false
    data     = abap_true
).

SUBMIT ('RM07MLBS')
AND RETURN.


DATA: lt_outtab TYPE STANDARD TABLE OF alv_t_t2.
FIELD-SYMBOLS: <lt_outtab> like lt_outtab.
DATA lo_data TYPE REF TO data.

TRY.
    " get data from SALV model"&nbsp;
    cl_salv_bs_runtime_info=>get_data_ref(
          IMPORTING
            r_data = lo_data
    ).
    ASSIGN lo_data->* to <lt_outtab>.
    BREAK-POINT.

  CATCH cx_salv_bs_sc_runtime_info.
ENDTRY.

Source: http://zevolving.com/2015/07/salv-table-22-get-data-directly-after-submit/

But this does not work. I get a type mismatch error in this line:

ASSIGN lo_data->* to <lt_outtab>.

What could be wrong?

Is there a way to do this generic? At runtime I don't know which report is to be called.

My overall goal is to get the report in XML or JSON format.

Solution

With the help of the answer of user mkysoft, this is the working solution, which exports the data in json format:

FUNCTION /Z_FOO/CALL_REPORT_XML.
*"----------------------------------------------------------------------
*"*"Lokale Schnittstelle:
*"  EXPORTING
*"     VALUE(EV_RESULT_JSON) TYPE  STRING
*"----------------------------------------------------------------------

DATA: lo_data        TYPE REF TO data.

" Let know the model
cl_salv_bs_runtime_info=>set(
 EXPORTING
   display  = abap_false
   metadata = abap_false
   data     = abap_true
).


SUBMIT ('RM07MLBS')
   WITH WERKS = '0557'
  AND RETURN.


" get data from SALV model
cl_salv_bs_runtime_info=>get_data_ref(
      IMPORTING
        r_data = lo_data
).

field-SYMBOLS <lv_data> type any table.
ASSIGN lo_data->* TO <lv_data>.
ev_result_json = /ui2/cl_json=>serialize( data = <lv_data> pretty_name = /ui2/cl_json=>pretty_mode-low_case ).

cl_salv_bs_runtime_info=>clear_all( ).

ENDFUNCTION.

This helped me to get it done: https://blogs.sap.com/2011/07/07/gain-programmatic-access-to-data-of-sapgui-alv-reports/