*what are the step by step events trigger in interactive report*

Question

Hi gurus,
pls explain event by event triggers in interactive report.
points will be rewarded.
Thanks,
Balakrishna.

Answer 1

Hi,
Interactive reporting allows the user to participate in retrieving and presenting data at each level during the session.  Instead of presenting one extensive and detailed list with cluttered information, with interactive reporting you can create a condensed basic list from which the user can call detailed information by positioning the cursor and entering commands.
Detailed information is presented in secondary lists. A secondary list may either overlay the basic list completely or appear in an additional dialog window on the same screen.  The secondary list can itself be interactive again. The basic list is not deleted when secondary list is created.
User can interact with the system by:
u2022     Double clicking or pressing F2
u2022     Selecting menu option
Like classical report, the interactive report is also event driven. Both the action mentioned above trigger events and code is written to handle these events.  The events triggered by this action are as follows:
u2022     At line-selection
u2022     At user-command
u2022     Top-of-Page During Line-Selection for Secondary Page Header info
Interactive report consists of one BASIC list and 20 secondary list. Basic list is produced by START-OF-SELECTION event. When the user double clicks on the basic list or chooses the menu option, the secondary list is produced. All the events associated with classical report except end-of-page are applicable only to basic list.
AT LINE-SELECTION event
Double clicking is the way most users navigate through programs. Double clicking on basic list or any secondary list triggers the event AT LINE-SELECTION. SY-LSIND denotes the index of the list currently created. For BASIC list it is always 0.  Following piece of code shows how to handle the event.
Start-of-selection.
Write: / u2018this is basic listu2019.
At line-selection.
Write : u2018this is first secondary listu2019.
In this case the output will be displayed on basic list i.e.
This is basic list.
When user double clicks on this line, the event at line-selection gets triggered and secondary list is produced, i.e. This is first secondary list.
You can go back to basic list by clicking on F3 or back icon on the standard tool bar.  For this list, the value of sy-lsind will be 1.
HIDE technique
In this case thins are much simpler. Consider the case, wherein you display fields from table sflight in basic list. When user double clicks on any sflight-carrid, you are displaying the detailed information related to that particular carrid on secondary list.  Hence there is a need to store the clicked carrid in some variable.  So that you can access this carrid for next list. ABAP/4 has facility; a statement called HIDE, which provides the above functionality.
HIDE command temporarily stores the content of clicked field in system area.
Syntax:
HIDE <FIELDS>.
This statement stores the contents of variable <f> in relation to the current output line (system field SY-LINNO) internally in the so-called HIDE area. The variable <f> must not necessarily appear on the current line.
You have to place the HIDE statement always directly after the output statement i.e., WRITE for the variable <f>.  As when you hide the variable, control is passed to next record.  While writing, WRITE statement takes that record from header and writes it on to the list, but when writing onto your interactive list you will miss out 1st record.
To hide several variables, use chain HIDE statement.
As soon as the user selects a line for which you stored HIDE fields, the system fills the variables in the program with the values stored.  A line can be selected.
u2022     By an interactive event.
For each interactive event, the HIDE fields of the line on which the cursor is positioned during the event are filled with the stored values.
The HIDE area is a table, in which the system stores the names and values of all HIDE fields for each list and line number.  As soon as they are needed, the system reads the values from the table.  (Please try to find the name of this table.)
Sy-lsind indicates the index of the list and can be used to handle all the secondary lists.  When the user double clicks on the line or presses F2, sy-lsind is increased by one and this new sy-lsind can be handled.  For example:
Write: / u2018this is basic listu2019.
u2022     Will create a basic list.
If sy-lsind = 1.
Write: / u2018this is first secondary listu2019.
Elseif sy-lsind = 2.
Write: / u2018This is second secondary listu2019.
Endif.
When this code is executed,
u2022     Basic list is produced.
u2022     When the user clicks on the basic list, sy-lsind becomes one.
u2022     AT LINE-SELECTION event is triggered.
u2022     Whatever is written under IF Sy-lsind = 1, gets executed.
u2022     Secondary list is produced.
u2022     Again if user clicks on this list, sy-lsind becomes two.
u2022     AT LINE-SELECTION gets triggered.
u2022     Code written under IF Sy-lsind = 2, gets executed.
A sample program for AT LINE-SELECTION.
AT USER-COMMAND
When the user selects the menu item or presses any function key, the event that is triggered is AT USER-COMMAND, and can be handled in the program by writing code for the same. The system variable SY-UCOMM stores the function code for the clicked menu item or for the function key and the same can be checked in the program.  Sample code would look like
AT USER-COMMAND.
Case sy-ucomm.
When u2018DISPu2019.
        Select * from sflight.
        Write sflight-carrid, sflight-connid.
        Endselect.
When u2018EXITu2019.
     LEAVE.
If GUI status, suppose you have set menu bar for two items and the function code is u2018DISPu2019 and u2018EXITu2019 respectively. If the user clicks the menu item u2018DISPLAYu2019, then function code u2018DISPu2019 is stored in the sy-ucomm and whatever is written under the when u2018DISPu2019, gets executed. This is applicable for EXIT as well.
Sy-lsind for the screen increases when the user clicks the menu item.
Usually you have combination of all the three navigations in your user interface, i.e., you have to create menu bar, assign function code for the function keys and write code to handle all this in addition to handling double clicking.
Things to remember while using all the combinations:
u2022     Sy-lsind increases even if you select menu-item.
u2022     When the user double clicks on particular line, value of sy-ucomm is u2018PICK.
u2022     If you set sy-lsind = 2 for your 4th secondary list, when control is transferred to the 2nd secondary list, all the other lists after 2nd are lost or memory allocated to them is lost.
u2022     Sy-lisel also gives you the value of clicked line but in this case you cannot differentiate between field. To retrieve the exact field, you have to know the field length of each field.
u2022     If you use statement SY-LSIND = 1.
The system reacts to a manipulation of SY-LSIND only at the end of an event, directly before displaying the secondary list. So, if within the processing block, you use statements whose INDEX options access the list with the index SY-LSIND, make sure that you manipulate the SY-LSIND field only after processing these statements. The best way is to have it always at the `as the last statementu2019 of the processing block.
Regards,
Bhaskar