Legacy Document

Inside Macintosh: Interapplication Communication /

Chapter 4 - Responding to Apple Events / Reference to Responding to Apple Events

Routines for Responding to Apple Events / Coercing Descriptor Types

AECoerceDesc

You can use the AECoerceDesc function to coerce the data in a descriptor record to another descriptor type.

FUNCTION AECoerceDesc (theAEDesc: AEDesc; toType: DescType; 
                       VAR result: AEDesc): OSErr;

theAEDesc

The descriptor record whose data is to be coerced.

toType

The desired descriptor type of the resulting descriptor record.

result

The resulting descriptor record.

DESCRIPTION

The AECoerceDesc function attempts to create a new descriptor record by coercing the specified descriptor record. Your application is responsible for using the AEDisposeDesc function to dispose of the resulting descriptor record once you are finished using it.

If AECoerceDesc returns a nonzero result code, it returns a null descriptor record (a descriptor record of type typeNull, which does not contain any data) unless the Apple Event Manager is not available because of limited memory.

RESULT CODES

noErr	0	No error
memFullErr	-108	Not enough room in heap zone
errAECoercionFail	-1700	Data could not be coerced to requested descriptor type

SEE ALSO

For a list of the descriptor types for which the Apple Event Manager provides coercions, see Table 4-1, which begins on page 4-45.