Here's how to do ALV (OO) with dynamic fcat, int table and editable data

Question

Hi everybody
Here's a more useful approach to ALV grid with OO using dynamic table, data NOT from DDIC, dynamic FCAT and how to get changed lines from the grid when ENTER key is pressed.
It's really not too dificult but I think this is more useful than the ever present SFLIGHT methods from the demos.
This also defines a subclass of cl_gui_alv_grid so you can access the protected attributes / methods of that class.
You don't need to add the class via SE24 -- done fron this ABAP.
When you run it click Edit for the first time.
After editing data press ENTER and the break point should bring you into the relevant method.
Code developed on NW2004S trial version but also works on rel 6.40 on a "Real" system.
The code should work without any changes on any system >=6.40.
All you need to do is to create a blank screen 100 via SE51  with a custom container on it called CCONTAINER1.
The rest of the code can just be uploaded into your system using the SE38 upload facility.
When running the program click on the EDIT button to enable the edit functionality of the grid.
Change your data and when you press ENTER you should get the break-point where you can see the original table and changed rows.
This program is actually quite general as it covers Dynamic tables, building a dynamic fcat where your table fields are NOT in the DDIC, intercepting the ENTER key via using an event, and accessing the protected attributes of the cl_gui_alv_grid by defining a subclass of this class in the abap.
I've seen various questions relating to all these functions but none in my view ever answers the questions in a simple manner. I hope this simple program will answer all these and show how using OO ALV is actually quite easy and people shouldn't be scared of using OO.
Have fun and award points if useful.
Cheers
Jimbo.
<b>PROGRAM zdynfieldcat.
Simple test of dynamic ITAB with user defined (not ddic) fields
Build dynamic fcat
use ALV grid to display and edit.
*When edit mode set to 1 toolbar gives possibility of adding and
*deleting rows.
*Define subclass of cl_gui_alv_grid so we can use protected attributes
*and methods.
Add event handler to intercept user entering data and pressing the
*ENTER key.
When enter key is pressed get actual value of NEW table (all rows)
rather than just the changed data.
*use new RTTI functionality to retrieve internal table structure
*details.
Create a blank screen 100  with a custom container called CCONTAINER1.
James Hawthorne
include <icon>.
define  any old internal structure  NOT in DDIC
types: begin of s_elements,
       anyfield1(20) type c,
       anyfield2(20) type c,
       anyfield3(20) type c,
       anyfield4(20) type c,
       anyfield5(11) type n,
       end of s_elements.
types:  lt_rows  type lvc_t_roid.
Note new RTTI functionality allows field detail retrieval
at runtime for dynamic tables.
data:   wa_element type s_elements ,
        wa_data type s_elements,
        c_index type sy-index,
        c_dec2 type s_elements-anyfield5,
        wa_it_fldcat type lvc_s_fcat,
        it_fldcat type lvc_t_fcat,
        lr_rtti_struc TYPE REF TO cl_abap_structdescr,    "RTTI
        lt_comp TYPE cl_abap_structdescr=>component_table,"RTTI
        ls_comp LIKE LINE OF lt_comp,                     "RTTI
        zog  like line of lr_rtti_struc->components,      "RTTI
        struct_grid_lset type lvc_s_layo,
        l_valid  type c,
        new_table type ref to data.
field-symbols: <dyn_table> type standard table,
               <actual_tab> type standard table,
               <fs1> type ANY,
               <FS2> TYPE TABLE.
data: grid_container1 type ref to cl_gui_custom_container.
class lcl_grid_event_receiver definition deferred.
data: g_event_receiver type ref to lcl_grid_event_receiver.
data: ls_modcell type LVC_S_MODI,
      stab type ref to data,
      sdog type  s_elements.      .
class lcl_grid_event_receiver definition.
  public section.
    methods:
    handle_data_changed
         for event data_changed of cl_gui_alv_grid
             importing er_data_changed,
       toolbar for event toolbar of cl_gui_alv_grid
                 importing e_object
                           e_interactive,
      user_command for event user_command of cl_gui_alv_grid
                 importing e_ucomm.
endclass.
*implementation of Grid event-handler class
class lcl_grid_event_receiver implementation.
method handle_data_changed.
code whatever required after data entry.
various possibilites here as you can get back Cell(s) changed
columns or the entire updated table.
Data validation is also possible here.
perform check_data using er_data_changed.
endmethod.
Method for handling all creation/modification calls to the toolbar
  method toolbar.
    data : ls_toolbar type stb_button.
Define Custom Button in the toolbar
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'EDIT' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Edit' to ls_toolbar-text.
    move icon_change_text to ls_toolbar-icon.
    move 'Click2Edit' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'UPDA' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Update' to ls_toolbar-text.
    move icon_system_save to ls_toolbar-icon.
    move 'Click2Update' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
    clear ls_toolbar.
    move 0 to ls_toolbar-butn_type.
    move 'EXIT' to ls_toolbar-function.
    move space to ls_toolbar-disabled.
    move 'Exit' to ls_toolbar-text.
    move icon_system_end to ls_toolbar-icon.
    move 'Click2Exit' to ls_toolbar-quickinfo.
    append ls_toolbar to e_object->mt_toolbar.
  endmethod.
  method user_command.
    case e_ucomm .
      when 'EDIT'.          "From Tool bar
        perform set_input.
         perform init_grid.
      when 'UPDA'.          "From Tool bar
        perform refresh_disp.
        perform update_table.
      when 'EXIT'.          "From Tool bar
        leave program.
    endcase.
  endmethod.
endclass.
class zcltest definition inheriting from  cl_gui_alv_grid.
define this as a subclass so we can access the protected attributes
of the superclass cl_gui_alv_grid
public section.
methods: constructor, disp_tab.
endclass.
need this now to instantiate object
as we are using subclass rather than the main cl_gui_alv_grid.
class zcltest implementation.
METHOD constructor.
CALL METHOD super->constructor
        exporting i_appl_events = 'X'
           i_parent = grid_container1.
endmethod.
method disp_tab.
FIELD-SYMBOLS: <outtab> TYPE STANDARD TABLE.
break-point 1.
mt_outtab is the data table held as a protected attribute
in class cl_gui_alv_grid.
ASSIGN me->mt_outtab->* TO <outtab>.  "Original data
do whatever you want with <outtab>
contains data BEFORE changes each time.
Note that NEW (Changed) table has been obtained already by
call to form check_data USING P_ER_DATA_CHANGED
         TYPE REF TO CL_ALV_CHANGED_DATA_PROTOCOL.
Entered data is in table defined by <fs2>
In this method you can compare original and changed data.
Easier than messing around with individual cells.
do what you want with data in <fs2>  validate / update / merge etc
endmethod.
endclass.
data :
    ok_code like sy-ucomm,
    save_ok like sy-ucomm,
    i4 type int4,
Container Object [grid_container]
now created via method constructor
in the subclass zcltest.
Control Object [grid]
grid1 type ref to zcltest,
Event-Handler Object [grid_handler]
grid_handler type ref to lcl_grid_event_receiver.
start-of-selection.
call screen 100.
module status_0100 output.
now display it as grid
if grid_container1 is initial.
    create object grid_container1
        exporting
          container_name = 'CCONTAINER1'.
    create object grid1.
     break-point 1.
    create object grid_handler.
    set handler:
       grid_handler->user_command for grid1,
       grid_handler->toolbar for grid1,
       grid_handler->handle_data_changed for grid1.
perform create_dynamic_fcat.
perform create_dynamic_itab.
perform populate_dynamic_itab.
perform init_grid.
perform register_enter_event.
set off ready for input initially
i4 = 0.
  call method grid1->set_ready_for_input
         exporting
           i_ready_for_input = i4.
endif.
endmodule.
module user_command_0100 input.
*PAI not needed in OO ALV anymore as User Commands are handled as events
*in method user_command.
*we can also get control if the Data entered and the ENTER is pressed by
*raising an event.
Control then returns to method handle_data_changed.
endmodule.
form create_dynamic_fcat.
get structure of our user table for building field catalog
Use the RTTI functionality
lr_rtti_struc ?= cl_abap_structdescr=>describe_by_data( wa_data ).
Build field catalog just use basic data here
colour specific columns as well
loop at lr_rtti_struc->components into zog.
c_index = c_index + 1.
clear wa_it_fldcat.
  wa_it_fldcat-fieldname = zog-name .
  wa_it_fldcat-datatype =  zog-type_kind.
  wa_it_fldcat-inttype =   zog-type_kind.
  wa_it_fldcat-intlen =    zog-length.
  wa_it_fldcat-decimals =  zog-decimals.
  wa_it_fldcat-lowercase = 'X'.
  if c_index eq 2.
  wa_it_fldcat-emphasize = 'C411'.
     endif.
    if c_index eq 3.
  wa_it_fldcat-emphasize = 'C511'.
   endif.
  append wa_it_fldcat to it_fldcat .
endloop.
endform.
form create_dynamic_itab.
Create dynamic internal table and assign to field sysmbol.
Use dynamic field catalog just built.
call method cl_alv_table_create=>create_dynamic_table
             exporting
                it_fieldcatalog = it_fldcat
             importing
                ep_table        = new_table.
assign new_table->* to <dyn_table>.
endform.
form populate_dynamic_itab.
load up a line of the dynamic table
c_dec2 = c_dec2 + 11.
wa_element-anyfield1 = 'Tabbies'.
wa_element-anyfield2 = 'ger.shepards'.
wa_element-anyfield3  = 'White mice'.
wa_element-anyfield4 =  'Any old text'.
wa_element-anyfield5 =  c_dec2.
append  wa_element to <dyn_table>.
endform.
form check_data USING P_ER_DATA_CHANGED
           TYPE REF TO CL_ALV_CHANGED_DATA_PROTOCOL.
Get altered data back
  ASSIGN   p_er_data_changed->mp_mod_rows TO <FS1>.
stab =       p_er_data_changed->mp_mod_rows.
ASSIGN STAB->* TO <FS2>.
LOOP AT <FS2> INTO sdog.
ALV grid display with altered data is now in <fs2>.
do any extra processing you want here
endloop.
now display new table
call method grid1->disp_tab.
endform.
form exit_program.
  call method grid_container1->free.
  call method cl_gui_cfw=>flush.
  leave program.
endform.
form refresh_disp.
  call method grid1->refresh_table_display.
endform.
form update_table.
The dynamic table here is the changed table read from the grid
after user has changed it
Data can be saved to DB or whatever.
loop at <dyn_table> into wa_element.
do what you want with the data here
endloop.
switch off edit mode again for next function
i4 = 0.
  call method grid1->set_ready_for_input
      exporting
          i_ready_for_input = i4.
endform.
form set_input.
i4 = 1.
  call method grid1->set_ready_for_input
     exporting
       i_ready_for_input = i4.
endform.
form switch_input.
if i4 = 1.
i4 = 0.
else.
i4 = 1.
endif.
  call method grid1->set_ready_for_input
     exporting
       i_ready_for_input = i4.
endform.
form init_grid.
Enabling the grid to edit mode,
     struct_grid_lset-edit = 'X'. "To enable editing in ALV
     struct_grid_lset-grid_title  = 'Jimbos Test'.
     call method grid1->set_table_for_first_display
       exporting
         is_layout           = struct_grid_lset
       changing
         it_outtab             =  <dyn_table>
         it_fieldcatalog       =  it_fldcat.
endform.
form register_enter_event.
call method grid1->register_edit_event
               exporting
                  i_event_id = cl_gui_alv_grid=>mc_evt_enter.
Instantiate the event or it won't work.
create object g_event_receiver.
set handler g_event_receiver->handle_data_changed for grid1.
endform.</b>

Answer 1

Hi there
IE7 doesn't give me the add new page option and I get 404 error when trying to access the "How to contribute" section.
I'll load up Firefox later (this browser usually works when IE7 doesn't always work properly).
I'll copy the stuff to the wiki when I've got the browser sorted out.
Cheers
jimbp