Wednesday, 9 January 2013

Alv Oops Display

Alv Oops Display
Step :

Now, we can figure out a primitive scheme to prepare our ALV Grid. As a control object, ALV Grid instance requires a container to be linked to the screen. Generally, an instance of the class “cl_gui_custom_container” is used for this purpose. Instances of some other container classes such as “cl_gui_docking_container”, “cl_gui_dialogbox_container” may also be used. In our example we take a custom container. To create a custom container instance, we need a custom control area on the screen.


Step 1: Add a custom control on the screen which will be related to the custom container. Let’s give it the name ‘CC_ALV’.

Step 2 : Declare global variables to be used for ALV Grid.


*-- Global data definitions for ALV
*--- ALV Grid instance reference
DATA gr_alvgrid TYPE REF TO cl_gui_alv_grid .
*--- Name of the custom control added on the screen
DATA gc_custom_control_name TYPE scrfname VALUE ‘CC_ALV’ .
*--- Custom container instance reference
DATA gr_ccontainer TYPE REF TO cl_gui_custom_container .
*--- Field catalog table
DATA gt_fieldcat TYPE lvc_t_fcat .
*--- Layout structure
DATA gs_layout TYPE lvc_s_layo .

Step 3 : Declare your internal table which is supposed to hold the list data. Let’s name it “gt_list”. Here is an example declaration.


*--- Internal table holding list data
DATA BEGIN OF gt_list OCCURS 0 .
INCLUDE STRUCTURE SFLIGHT .
*--In further sections, some additional fields will added here
*--for some functionality
DATA END OF gt_list .

Step 4 : Somewhere in your program before calling list display, fill your list data as you want. Here, it is not our concern what the data are. We assume the internal table is filled reasonably. We will use the data of table SFLIGHT as our list data.

Step 5 : Call the screen which comprises the ALV Grid control. At PBO of this screen we will deal with creating the ALV Grid instance.


*--PBO
PROCESS BEFORE OUTPUT .
...
MODULE display_alv .

...
MODULE display_alv OUTPUT .
PERFORM display_alv .
ENDMODULE .


Step 6 : Now, it is high time we wrote something to play. So, this piece will be the one we will deal mainly. What we do is, checking whether an instance of the container (or ALV Grid) exists. If it exists, refreshing it, and if not, creating and setting ALV for the first display.
FORM display_alv .

IF gr_alvgrid IS INITIAL .
*----Creating custom container instance
CREATE OBJECT gr_ccontainer
EXPORTING
container_name = gc_custom_control_name
EXCEPTIONS
cntl_error = 1
cntl_system_error = 2
create_error = 3
lifetime_error = 4
lifetime_dynpro_dynpro_link = 5
others = 6 .
IF sy-subrc <> 0.
*--Exception handling
ENDIF.
*----Creating ALV Grid instance
CREATE OBJECT gr_alvgrid
EXPORTING
i_parent = gr_ccontainer
EXCEPTIONS
error_cntl_create = 1
error_cntl_init = 2
error_cntl_link = 3
error_dp_create = 4
others = 5 .


IF sy-subrc <> 0.
*--Exception handling
ENDIF.
*----Preparing field catalog.
PERFORM prepare_field_catalog CHANGING gt_fieldcat .
*----Preparing layout structure
PERFORM prepare_layout CHANGING gs_layout .
*----Here will be additional preparations
*--e.g. initial sorting criteria, initial filtering criteria, excluding
*--functions
CALL METHOD gr_alvgrid->set_table_for_first_display
EXPORTING
* I_BUFFER_ACTIVE =
* I_CONSISTENCY_CHECK =
* I_STRUCTURE_NAME =
* IS_VARIANT =
* I_SAVE =
* I_DEFAULT = 'X'
is_layout = gs_layout
* IS_PRINT =
* IT_SPECIAL_GROUPS =
* IT_TOOLBAR_EXCLUDING =
* IT_HYPERLINK =
CHANGING
it_outtab = gt_list[]
it_fieldcatalog = gt_fieldcat
* IT_SORT =
* IT_FILTER =
EXCEPTIONS
invalid_parameter_combination = 1
program_error = 2
too_many_lines = 3
OTHERS = 4 .


IF sy-subrc <> 0.
*--Exception handling
ENDIF.
ELSE .
CALL METHOD gr_alvgrid->refresh_table_display
* EXPORTING
* IS_STABLE =
* I_SOFT_REFRESH =
EXCEPTIONS
finished = 1
OTHERS = 2 .
IF sy-subrc <> 0.
*--Exception handling
ENDIF.
ENDIF .
ENDFORM .