Explain Simple Report?

Answer

Important function modules in these report are -

• Reuse_alv_fieldcatalog_merge
• Reuse_alv_list_display
• Reuse_alv_events_get
• Reuse_alv_grid_display
• Reuse_alv_commentary_write

REUSE_ALV_FIELDCATALOG_MERGE

This function module is used to populate a field catalog which is essential to display the data in ALV.

If the output data is from a single dictionary table and all the columns are selected, then we need not exclusively create the field catalog. Its enough to mention the table name as a parameter (I_structure_name) in the REUSE_ALV_LIST_DISPLAY. But in other cases we need to create it.

Note : Fieldcatalog can be filled manually also by filling up all the required details into the internal table

Important parameters in are:

1. Export:

• I_program_name : report id
• I_internal_tabname : the internal output table
• I_inclname : include or the report name where all the dynamic forms are handled.

2. Changing

• ct_fieldcat : an internal table with the type SLIS_T_FIELDCAT_ALV which is declared in the type pool SLIS.

REUSE_ALV_LIST_DISPLAY

This is the function module which prints the data.

The important parameters are:

1. Export:

• I_callback_program : report id
• I_bypassing_buffer : 'X'
• I_buffer_active : ' '
• I_callback_pf_status_set : routine where a user can set his own pf status or change the functionality of the existing pf status.
• I_callback_user_command : routine where the function codes are handled.

• I_structure name : name of the dictionary table
• Is_Layout : structure to set the layout of the report
• It_fieldcat : internal table with the list of all fields and their attributes which are to be printed (this table can be populated automatically by the function)
• It_events : internal table with a list of all possible events of ALV and their corresponding form names.

2. Tables:

• a. t_outtab : internal table with the data to be output

REUSE_ALV_EVENTS_GET:

Returns table of possible events for a a list type

1. Import:

Et_Events :The event table is returned with all possible CALLBACK events for the specified list type (column 'NAME'). For events to be processed by the Callback, their 'FORM' field must be filled. If the field is initialized, the event is ignored. The entry can be read from the event table, the field 'FORM' filled and the entry modified using constants from the type pool SLIS.

2. Export:

I_list_type: 0 = simple list REUSE_ALV_LIST_DISPLAY

1 = hierarchical-sequential list  REUSE_ALV_HIERSEQ_LIST_DISPLAY

2 = simple block list REUSE_ALV_BLOCK_LIST_APPEND

3 = hierarchical-sequential block list   REUSE_ALV_BLOCK_LIST_HS_APPEND

REUSE_ALV_GRID_DISPLAY

A new function from ABAP4.6 version, to display the results in grid rather than a preview.

Parameters : same as reuse_alv_list_display

Note:Grid cannot handle high volumes. Functions like sort, scrolling down consumes a lot of resources / time if the volume of data to be displayed is high. There is no clear cut definition such that if the amount of data is X go for list or grid  but the developer has to take a call based on his experience. If not sure, then list is the better option

REUSE_ALV_COMMENTARY_WRITE

This is used in the Top-of-page event to print the headings and other comments for the list.

Important Parameters

• It_list_commentary : Internal table with the headings of the type slis_t_listheader.