BUG: CHANGE WHEN and VALID Clauses Don't Work with Arrow Keys

• Microsoft FoxPro for Windows, versions 2.5, 2.5a, 2.5b, 2.6, 2.6a

SYMPTOMS

If you use the CHANGE command to view or change records in a table, the CHANGE WHEN clause doesn't work correctly when you press any of the ARROW keys to move between records.

Once a field is changed, if you continue to press any of the ARROW keys or the ENTER key to move between records, the CHANGE VALID will behave like a FORCED VALID until you press the PAGE UP or PAGE DOWN key.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The program below demonstrate the problem with the WHEN and the VALID clauses of the CHANGE command. Depending on which key combination is used, you may run into one or more of the following problems:

• The WHEN clause for current record is not executed.
• The previous WHEN result is still active.
• The VALID clause for current record is executed even when no data was changed.

Steps to Reproduce Problem

1. Create and then run a program containing the following code. When running the program, use only the PAGE UP and PAGE DOWN keys to move between records.

   SET DEFAULT TO SYS(2004)+"tutorial" USE customer testfile=SYS(3) COPY TO &testfile USE &testfile

   CHANGE FIELDS cno, company, address WHEN chgwhen() VALID chgvalid()

   CLOSE ALL WAIT WINDOW "CLOSING ALL FILES" NOWAIT DELETE FILE &testfile..dbf

   FUNCTION chgwhen * MOD returns 0 for all even records, and 1 for all odd records. IF MOD(RECNO(),2)=0

          WAIT WINDOW 'W: Recno is ' + ALLTRIM(STR(RECNO())) + ;
          '. Even records are Editable' NOWAIT
          RETURN .T.
          && Returning True allow the current record to be edited
   

   ELSE

          WAIT WINDOW 'W: Recno is ' + ALLTRIM(STR(RECNO())) + ;
          '. Odd records are READ-ONLY' NOWAIT
          RETURN .F.
          && Returning False makes the current record read only
   

   ENDIF

   FUNCTION chgvalid IF MOD(RECNO(),2)=0

          WAIT WINDOW 'V: Recno is ' + ALLTRIM(STR(RECNO())) + ;
          '. Even record changes validated OK'
          RETURN .T.
   

   ELSE

          WAIT WINDOW 'V1: Recno is ' + ALLTRIM(STR(RECNO())) + ;
            '. Odd records should be READ-ONLY'
          WAIT WINDOW 'V2: Current record was changed. RECORD WHEN '+ ;
            'protection failed, or'
          WAIT WINDOW 'V3: RECORD VALID is behaving like a FORCED VALID '+ ;
            'because Previous record was changed.'
          RETURN .T.
      ENDIF
   
   

2. Change or delete some of the fields in one or more of the even records, and try to change some of the fields in the odd records.

3. Repeat steps 1 and 2 using the ARROW keys as well as the PAGE UP and PAGE DOWN keys.