HIDE TECHNIQUE and statement in SAP ABAP


You use the HIDE technique while creating a list level to store line-specific information for later use. To do so, use the HIDE statement as follows:

HIDE <f>.

This statement places the contents of the variable <f> for the current output line (system field SY­LINNO) into the HIDE area. The variable <f> must not necessarily appear on the current line.

To make your program more readable, always place the HIDE statement directly after the output statement for the variable <f> or after the last output statement for the current line.

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

· 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.

· by the READ LINE statement.

You can think of the HIDE area as 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. The example below presents some of the essential features of interactive reporting. The basic list contains summarized information. By means of the HIDE technique, each detail list contains more details.

The following program is connected to the logical database F1S.

REPORT demo_list_hide NO STANDARD PAGE HEADING.

TABLES: spfli, sbook.

DATA: num TYPE i,
dat TYPE d.
 

START-OF-SELECTION.
 num = 0.
 SET PF-STATUS ‘FLIGHT’.
 

GET spfli.
num = num + 1.
 WRITE: / spfli-carrid, spfli-connid,
          spfli-cityfrom, spfli-cityto.HIDE: spfli-carrid, spfli-connid, num.

END-OF-SELECTION.
 CLEAR num.
 

TOP-OF-PAGE. WRITE ‘List of Flights’.ULINE. WRITE ‘CA CONN FROM TO’. ULINE.

TOP-OF-PAGE DURING LINE-SELECTION.
 CASE sy-pfkey.
 

WHEN ‘BOOKING’.
 WRITE sy-lisel.
ULINE.
 

 WHEN ‘WIND’.
 WRITE: / ‘Booking’, sbook-bookid,’Date ‘, sbook-fldate.ULINE. ENDCASE.

AT USER-COMMAND.
 CASE sy-ucomm.
 

WHEN ‘SELE’.
 

 IF num NE 0. SET PF-STATUS ‘BOOKING’. CLEAR dat. SELECT * FROM sbook WHERE carrid = spfli-carridAND

IF sbook-fldate NE dat.connid = spfli-connid. dat = sbook-fldate. SKIP. WRITE / sbook-fldate.POSITION 16.

 ELSE. NEW-LINE. POSITION 16.

 ENDIF.
 WRITE sbook-bookid.
 HIDE: sbook-bookid, sbook-fldate, sbook-custtype,

sbook-smoker, sbook-luggweight, sbook-class.ENDSELECT. IF sy-subrc NE 0.

WRITE / ‘No bookings for this flight’.

ENDIF.

 num = 0.

 CLEAR sbook-bookid.

 ENDIF.
 WHEN ‘INFO’.

 IF NOT sbook-bookid IS INITIAL.

 SET PF-STATUS ‘WIND’.

 SET TITLEBAR ‘BKI’.

 WINDOW STARTING AT 30 5 ENDING AT 60 10.

 WRITE: ‘Customer type :’, sbook-custtype,

/ ‘Smoker :’, sbook-smoker,

/ ‘Luggage weight :’, sbook-luggweight UNIT ‘KG’,

/ ‘Class :’, sbook-class.

ENDIF.
 ENDCASE.

 

At the event START-OF-SELECTION, the system sets the status FLIGHT for the basic list. In status FLIGHT, function code SELE (text SELECT) is assigned to function key F2 and to a pushbutton. So the event AT USER-COMMAND is triggered if the user double-clicks, presses F2, or chooses the pushbutton SELECT.

The three fields SPFLI-CARRID, SPFLI-CONNID, and NUM are stored in the HIDE area while creating the basic list. After selecting a line, the system displays the detail list defined in the AT USER-COMMAND event for function code SELE. In the AT USER-COMMAND event, the system refills all fields of the selected line that were stored in the HIDE area. You use NUM to check whether the user selected a line from the actual list. The detail list has status BOOKING, where F2 is assigned to function code INFO (text: Booking Information).  The detail list presents data that the program selected by means of the HIDE fields of the basic list. For each list line displayed, the system stores additional information in the HIDE area.

If the user selects a line of the detail list, the system displays the “hidden” information in a dialog box with the status WIND. The status has the type Dialog box, and contains the proposed functions for a list status.  The program uses SBOOK­BOOKID to check whether the user selected a valid line.

The program itself sets all page headers and the title bar of the dialog box.