ABAP List Viewer

ABAP List Viewer
The common features of report are column alignment, sorting, filtering, subtotals, totals etc. To implement these, a lot of coding and logic is to be put. To avoid that we can use a concept called ABAP List Viewer (ALV).
Using ALV, we can have three types of reports:
1. Simple Report
2. Block Report
3. Hierarchical Sequential Report
There are some function modules which will enable to produce the above reports without much effort.
All the definitions of internal tables, structures
and constants are declared in a type-pool called SLIS.
Simple Report
The important function modules are:
•Reuse_alv_list_display
•Reuse_alv_fieldcatalog_merge
•Reuse_alv_events_get
•Reuse_alv_commentary_write
•Reuse_alv_grid_display
A. REUSE_ALV_LIST_DISPLAY: This is the function module which prints the data.
The important parameters are:
1. Export:
a. I_callback_program : report id
b. I_callback_pf_status_set : routine where a user can set his own pf status or change the
functionality of the existing pf -status.
c. I_callback_user_command : routine where the function codes are handled.
d. I_structure name : name of the dictionary table
e. Is_Layout : structure to set the layout of the report
f. 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
module REUSE_ALV_FIELDCATALOG_MERGE)
g. It_events : internal table with a list of all possible events of ALVand their
corresponding routine names.
2. Tables:
a. t_outtab : internal table with the data to be output
B. REUSE_ALV_FIELDCATALOG_MERGE:
This function module is used to populate a fieldcatalog 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.
The important parameters are:
1. Export:
a. I_program_name : report id
b. I_internal_tabname : the internal output table
c. 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.
C . 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
1 = hierarchical-sequential list
2 = simple block list
3 = hierarchical-sequential block list
D. REUSE_ALV_COMMENTARY_WRITE : This is used in the Top-of-page event to print the headings and other comments for the list.
1. It_list_commentary : Internal table with the headings of the type slis_t_listheader.
This internal table has three fields:
Typ : ‘H’ - header, ‘S’ - selection, ‘A’ - action
Key : only when typ is ‘S’.
Info : the text to be printed
E. REUSE_ALV_GRID_DISPLAY: A new function in 4.6 version, to display the results in grid rather than as a list.
Parameters : same as reuse_alv_list_display
HIERARCHICAL REPORTS
A. REUSE_ALV_HIERSEQ_LIST_DISPLAY
1. Export:
a. I_CALLBACK_PROGRAM
b. I_CALLBACK_PF_STATUS_SET
c. I_CALLBACK_USER_COMMAND
d. IS_LAYOUT
e. IT_FIELDCAT
f. IT_EVENTS
g. I_TABNAME_HEADER : Name of the internal table in the program containing the output data of the
highest hierarchy level.
h. I_TABNAME_ITEM : Name of the internal table in the program containing the output data of the
lowest hierarchy level.
i. IS_KEYINFO : This structure contains the header and item table field names which link the two tables
(shared key).
2. Tables
a. T_OUTTAB_HEADER : Header table with data to be output
b. T_OUTTAB_ITEM : Name of the internal table in the program containing the output data of the
lowest hierarchy level.
BLOCK REPORT
This is used to display multiple lists continuously.
The important functions used in this report are:
A. REUSE_ALV_BLOCK_LIST_INIT
B. REUSE_ALV_BLOCK_LIST_APPEND
C. REUSE_ALV_BLOCK_LIST_DISPLAY
D. REUSE_ALV_BLOCK_HS_LIST_APPEND
A. REUSE_ALV_BLOCK_LIST_INIT
Parameters:
a. I_CALLBACK_PROGRAM
b. I_CALLBACK_PF_STATUS_SET
c. I_CALLBACK_USER_COMMAND
This function module is used to set the default GUI status etc.
B. REUSE_ALV_BLOCK_LIST_APPEND
Export :
a. IS_LAYOUT : layout settings for block
b. IT_FIELDCAT : field catalog
c. I_TABNAME : Internal table name of the output data
d. IT_EVENTS : internal table name with all possible events
Tables :
a. T_OUTTAB : internal table with output data.
This function module adds the data to the block.
INTERNAL TABLES IN SLIS
Slis_t_fieldcat_alv :
This internal table contains the field attributes. This internal table can be populated automatically by using ‘REUSE_ALV_FIELDCATALOG_MERGE’.
Important Attributes:
a. col_pos : position of the column
b. fieldname : internal fieldname
c. tabname : internal table name
d. ref_fieldname : fieldname (dictionary)
e. ref_tabname : table (dictionary)
f. key(1) : column with key-color
g. icon(1) : icon
h. hotspot(1) : hotspot
i. Symbol(1) : symbol
j. Checkbox(1) : checkbox
k. just(1) : (R)ight (L)eft (C)ent
l. do_sum(1) : sum up
m. no_out(1) : (O)blig. (X)no out
n. outputlen : output length
o. seltext-l : long key word
p. seltext_m : middle key word
q. seltext_s : short key word
r. reptext_ddic : heading(ddic)
s. ddictxt(1) : (S)hort (M)iddle (L)ong
t. datatype : datatype
SLIS_T_EVENT :
Internal table for storing all the possible events of the ALV. This can be populated by the function module Reuse_alv_events_get
The columns are :
name : name of the event
form : name of the routine
SYNTAXES FOR THE ROUTINES
I_CALLBACK_PF_STATUS_SET
Syntax :
FORM set_pf_status USING rt_extab TYPE slis_t_extab
The table RT_EXTAB contains the function codes which are hidden in the standard interface.
I_CALLBACK_USER_COMMAND
Syntax :
FORM user_command USING r_ucomm LIKE sy-ucomm
rs_selfield TYPE slis_selfield.
The parameter r_ucomm contains the function code.
The structure rs_selfield has the details about the current cursor position.