Specify types for descriptors.
- macOS 10.0+
- Mac Catalyst 13.0+
- Core Services
The constants described here specify the data type for a descriptor and show the kind of data stored in a descriptor with that type.
Descriptors are the building blocks used by the Apple Event Manager to construct Apple event attributes and parameters. A descriptor is a data structure of type
AEDesc, which consists of data storage and a descriptor type that identifies the type of the data. A descriptor type is defined by the data type
Desc. AppleScript defines descriptor type constants for a wide variety of common data types. For additional types, see Numeric Descriptor Type Constants and Other Descriptor Type Constants. For a complete listing, including data types such as units of length, weight, and volume, see the Apple Event Manager and Open Scripting Architecture header files.
For the constant
type, the data that specifies the application URL takes the following format:
As indicated by this format:
usernameis optional. If present, an
'@'must appear before the host name.
passwordis optional. If present,
usernameis not optional, and the password must be separated from the username by a
':'and must precede the
Appis not optional; if it contains non-UTF-8 characters or white space, it must be URL-encoded (for example,
pidare optional. If
Appare ignored and the event is delivered only to applications with the given process id. If
uidis present, events are directed to the application name owned by the given user id.
The following are examples of valid URLs:
The availability of user identifiers provides enhanced Apple event support for Fast User Switching. Such identifiers make it possible to send Apple events to applications running in any session, if the uids of the processes match.
uid 0) processes are allowed to send Apple events to any process in any session. Non-root processes can only target applications that match their uid.