Scripting Additions Guide

Types of Scripting Additions 85
CHAPTER 3
Writing Scripting Additions 3
Figure 3-0
Listing 3-0
Table 3-0
This chapter is intended for experienced Macintosh programmers. Before
reading this chapter, you should have a thorough understanding of the Apple
Event Manager, Apple event terminology resources, and the C or Pascal
programming language. For information about the Apple Event Manager
and Apple event terminology resources, see Inside Macintosh: Interapplication
Communication.
This chapter describes
■ types of scripting additions
■ the scripting addition size resource
■ how to use other resources with scripting additions
■ a trick for using records as scripting addition reply values
■ scripting addition limitations
It also includes code written in C for a sample scripting addition.
Types of Scripting Additions 0
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.