AppleScript: The Definitive Guide, 2nd Edition

Dictionary

AppleScript is a little language. It is also an extensible language. The purpose of AppleScript is to communicate with scriptable applications by means of Apple events; each such application can extend the terminology of the language in its own way, defining a repertory of Apple events to which it is prepared to respond, along with the English-like AppleScript terms to which these Apple events and their various parts correspond. To be scriptable with AppleScript, the application must publish information about this repertory. The mechanism by which this publication takes place is a resource called a dictionary.

The AppleScript scripting component uses the dictionary when compiling and decompiling a script, for two purposes:

• To confirm, at compile time, that the English-like terms used by the AppleScript programmer are legal

• To translate, at compile time and at decompile time, between English-like terms and Apple event structures

Not only does a scriptable application have a dictionary; a scripting addition does too, and for the very same reasons. (In fact, AppleScript itself has a dictionary.)

Dictionary Formats

A dictionary may be expressed in any of three formats :

The 'aete ' resource

The 'aete' resource is present in scriptable applications in Mac OS 9 and before, and in Carbon applications in Mac OS X (and optionally in Cocoa applications as well). For information about its format, see:

http://developer.apple.com/documentation/mac/IAC/IAC-308.html

In Xcode, to see a header ...