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ABL Reference
ABL Syntax Reference : HANDLE function
 

HANDLE function

Converts a string representation of a handle to a valid handle. If the string does not correlate to a valid handle in the session, the function returns 0.

Syntax

HANDLE ( handle-string )
Caution: Use this function only to convert a handle previously stored as a string value back to a valid handle. If you convert an arbitrary string to handle using this function and then reference the new handle, a system error will occur. If you use the VALID-HANDLE function to validate a handle generated from an arbitrary string value, a system error will occur.
handle-string
A string representation of a handle. Since handles are integer values, the string must contain only numeric characters.

Example

The following procedure creates a frame, stores the handle of the frame as a string value, deletes the frame, converts the string representation of the frame handle back to a valid handle, and then tests if the handle is valid:
r-widhd.p
DEFINE VARIABLE whand AS HANDLE    NO-UNDO.
DEFINE VARIABLE chand AS CHARACTER NO-UNDO.

CREATE FRAME whand.
chand = STRING(whand).
DELETE WIDGET whand.
whand = HANDLE(chand).
MESSAGE VALID-HANDLE(whand) VIEW-AS ALERT-BOX INFORMATION BUTTONS OK.
The VALID-HANDLE function returns a FALSE value because the frame was deleted and the handle is no longer valid.

Notes

*The HANDLE function can convert the string representation of procedure, system, and widget handles.
*For SpeedScript, the only valid use is to convert the handle of a QUERY object that you create using the CREATE WIDGET statement.

See also

CREATE widget statement, DATE function, DECIMAL function, INTEGER function, STRING function, VALID-HANDLE function