All Databases Inside Mac - AppleEvents

AEGetAttributePtr

Obtain data contained in an Apple Event attribute

#include <AppleEvents.h> Apple Event Manager

OSErr AEGetAttributePtr( theAppleEvent, theAEKeyword, desiredType,

typeCode, dataPtr, maximumSize,

actualSize );

AppleEvent * theAppleEvent ; Apple event record

AEKeyword theAEkeyword ; Apple Event keyword

DescType desiredType ; Descriptor type

DescType * typeCode ; pointer to descriptor type

Ptr dataPtr ; pointer to data buffer

Size maximumSize ; maximum size of data buffer

Size * actualSize ; actual size of data field

returns Error Code; 0 = no error

You can use the AEGetAttributePtr function to get a pointer to a buffer that

contains the data from a specified Apple event attribute.

The AEGetAttributePtr function uses a buffer to return the data from an

Apple event attribute with the specified keyword, which it attempts to coerce

to the descriptor type specified by the desiredType parameter. The keyword

can be one of the following:

Attribute keyword Description

keyAddressAttr Address of target application

keyEventClassAttr Event class of Apple event

keyEventIDAttr Event ID of Apple event

keyEventSourceAttr Source of the Apple event

keyInteractLevelAttr Settings for allowing the

Apple Event Manager to bring a server

application to the foreground

keyMissedKeywordAttr First required parameter

remaining in an Apple event.

keyOptionalKeywordAttr List of optional parameters for the

Apple event

keyReturnIDAttr Return ID for reply Apple event

keyTimeoutAttr Length of time in ticks that the

client will wait for a reply or a

result from the server

keyTransactionIDAttr Transaction ID identifying a series

of Apple events

The parameter theAppleEvent is the Apple event containing the desired

attribute.

The parameter theAEKeyword is the keyword that specifies the desired

attribute.

The desiredType parameter is the descriptor type of the data to be returned; if

the desired attribute is not of this type, the Apple Event Manager attempts

to coerce it into this type. If the value of desiredType is typeWildCard, no

coercion is performed, and the descriptor type of the returned data is the same

as the descriptor type of the attribute. The returned data's descriptor type is

returned in the typeCode parameter.

The dataPtr parameter is a pointer to the buffer for storing the data that is

returned.

The maximumSize parameter is the maximum length, in bytes, of the data to

be returned.

The AEGetAttributePtr function returns in the actualSize parameter the

actual length, in bytes, of the data for the attribute. If this value is larger than

the value of maximumSize, not all of the data for the attribute was returned.

For an example program showing use of this routine, see the description in

Writing Apple Event Handlers.

Result codes

noErr (0) No error

memFullErr (-108) Not enough room in heap zone

errAECoercionFail  (-1700) Data could not be  coerced to descriptor type
errAEDescNotFound  (-1701) Descriptor type was not found
 errAENotAEDesc (-1704) Not a valid descriptor  record
 errAEReplyNotArrived (-1718) Reply has not yet arrived

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