Inside Macintosh: AppleScript Scripting Additions Guide /

Chapter 3 - Writing Scripting Additions

Types of Scripting Additions

There are two types of scripting additions:

• Apple event handler scripting additions (language extensions)
• Apple event coercion scripting additions (data coercions)

Both types are loaded by the AppleScript extension when needed if the scripting addition files are installed in the Scripting Additions folder. Each
type of scripting addition consists of a file of type 'osax' and a creator of
type 'ascr'. The name of the 'osax' resource tells the scripting addition loading mechanism what type of scripting addition it is.

A scripting addition resource file may contain up to four kinds of resource:
(1) a code resource of type 'osax' that contains the executable code for the scripting addition, (2) an 'aete' resource that describes the terminology provided by the scripting addition, (3) a resource of type 'osiz' that informs AppleScript whether the scripting addition has any owned resources and whether it responds to commands sent from other computers on a network, and (4) any owned resources for the scripting addition, such as dialog definitions, strings, and sounds.

The next two sections describe the differences between 'osax' resources
for Apple event handlers and 'osax' resources for Apple event coercions.
For information about writing an 'aete' resource, see Inside Macintosh: Interapplication Communication. "The Scripting Addition Size Resource," which describes the format of the 'osiz' resource.

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Subtopics

Apple Event Handler Scripting Addition

Apple Event Coercions Scripting Addition