Alternative to Changing Table Under POPUP...PROMPT FIELD

• Microsoft FoxPro for Windows, versions 2.5, 2.5a, and 2.5b
• Microsoft FoxPro for MS-DOS, versions 2.5, 2.5a or 2.5b
• Microsoft FoxPro for Macintosh, version 2.5b

SUMMARY

When a popup is defined with the PROMPT FIELD clause, closing the database file on which the popup is based when the popup is still in memory can cause problems.

MORE INFORMATION

In a program, it is possible to close and delete the database on which a POPUP ... PROMPT FIELDS command is based and then substitute another database in place of the original. The new database can have a different structure, a different number of records, and so on. However, FoxPro is not designed to allow for the deletion and substitution of databases underneath active or defined popups. This practice is not supported and should not be used.

The following program demonstrates a method by which the table that underlies a POPUP ... PROMPT FIELD can be closed and re-created while the popup is in memory.

  * When this program is executed, select an option on the
  * popup and press the ENTER key to call "PROCEDURE popper".
  * The F5 key should be used to deactivate the popup.
  * Press the F5 key at any time to deactivate the popup.

  CLOSE ALL
  SET SAFETY OFF

  ON KEY LABEL f5 DEACTIVATE POPUP test

  CREATE TABLE test (city C(10))
  INSERT INTO test (city) VALUES ("Seattle")
  INSERT INTO test (city) VALUES ("Boston")

  DEFINE POPUP test FROM 02,02 PROMPT FIELD city
  ON SELECTION POPUP test DO popper
  ACTIVATE POPUP test
  RELEASE POPUP test

  PROCEDURE popper

    SELECT test

    * At this point, the table is closed. A new table
    * is created. The active popup is based on a
    * different table, and is unaware that these
    * changes are occurring. Although this type of
    * code may appear to function properly, it is
    * unsupported and subject to change in the future.

    USE
    CREATE TABLE test (city C(10))
    INSERT INTO test (city) VALUES ("Chicago")
    INSERT INTO test (city) VALUES ("New York")

  RETURN