Update Database from editable ALV

Hello,

I'm working on a program based on the Model View Controller pattern.

The model selects data from a database table into an internal table and this table is later displayed in an ALV grid by the view.

This is all working fine.

Now I made two columns editable with a field catalog. Now I enabled the "save"-button on the PF-STATUS to save the changes made in the ALV into the database table.

The code isn't working and I just can't find out why.

So this is my method to react on user command (it's a controller-method):

METHOD react_to_user_command.

CASE iv_ok_code.
WHEN 'BACK'.
LEAVE TO SCREEN 0.
WHEN 'EXIT'.
LEAVE PROGRAM.
WHEN 'SAVE'.

DATA gt_curto_pds_chg_new TYPE gtab_curto_pds_chg.

gt_curto_pds_chg_new = go_controller->go_view->get_data( ).
go_controller->go_model->update_data(

it_curto_pds_chg_new = gt_curto_pds_chg_new ).

ENDCASE.
ENDMETHOD.

This is the get_data( )-method:

METHOD get_data.
go_alv->check_changed_data( ).
rt_curto_pds_chg = gt_curto_pds_chg.
ENDMETHOD.

And this is my update_data( )-method:

METHOD update_data.

DATA: ls_curto_pds_chg_new TYPE curto_pds_chg,
ls_curto_pds_chg TYPE curto_pds_chg.


LOOP AT it_curto_pds_chg_new INTO ls_curto_pds_chg_new.


READ TABLE gt_curto_pds_chg

INTO ls_curto_pds_chg

WITH KEY ch_id = ls_curto_pds_chg_new-ch_id.


IF ls_curto_pds_chg_new <> ls_curto_pds_chg.
UPDATE curto_pds_chg FROM ls_curto_pds_chg_new.
ENDIF.

ENDLOOP.

ENDMETHOD.

Before I implemented the whole update thing I just wrote the WHEN 'SAVE' statement and let it call the method display( ) again just to test if it would show the new or the old table in the ALV. It showed the new table so I thought I could go on and implement the whole thing.

Debugging it now I can see that the table I get from Get_data( ) is already a not updated one and I just don't know why since the table is a changing parameter when building the ALV. I give you my code for the display( )-method as well.

METHOD display.

DATA: lt_fieldcat_fm TYPE slis_t_fieldcat_alv, "field catalog table for FM
ls_fieldcat_fm TYPE slis_fieldcat_alv, "field catalog structure for loop
lt_fieldcat_cl TYPE lvc_t_fcat, "field catalog table for alv method
ls_fieldcat_cl TYPE lvc_s_fcat. "field catalog structure for loop



* builds a field catalog based on the structure of curto_pds_chg
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'
EXPORTING
i_structure_name = 'CURTO_PDS_CHG'
CHANGING
ct_fieldcat = lt_fieldcat_fm
EXCEPTIONS
inconsistent_interface = 1
program_error = 2
OTHERS = 3.



* loops the field catalog given from the function module into one
* with a structure the alv display method accepts
LOOP AT lt_fieldcat_fm INTO ls_fieldcat_fm.
MOVE-CORRESPONDING ls_fieldcat_fm TO ls_fieldcat_cl.
APPEND ls_fieldcat_cl TO lt_fieldcat_cl.
ENDLOOP.



* makes two columns editable (CHANGE & PROCESS)
DATA: ls_fieldcat TYPE REF TO lvc_s_fcat.
READ TABLE lt_fieldcat_cl
WITH KEY fieldname = 'CHANGE' REFERENCE INTO ls_fieldcat.
ls_fieldcat->edit = 'X'.
READ TABLE lt_fieldcat_cl
WITH KEY fieldname = 'PROCESS' REFERENCE INTO ls_fieldcat.
ls_fieldcat->edit = 'X'.




* builds alv grid
IF go_container IS INITIAL.

CREATE OBJECT go_container
EXPORTING
container_name = 'CONTAINER'.


CREATE OBJECT go_alv
EXPORTING
i_parent = go_container.


CALL METHOD go_alv->set_table_for_first_display
EXPORTING
i_structure_name = 'CURTO_PDS_CHG'
CHANGING
it_outtab = gt_curto_pds_chg
it_fieldcatalog = lt_fieldcat_cl.
ELSE.
go_alv->refresh_table_display( ).
ENDIF.


ENDMETHOD.

Can anybody spot the mistake why my database table is not updating?