AppleScript in a Nutshell

Apple Event Classes and Objects

You have read about Apple events, which are action words or verbs (activate, delete). Apple event classes (and the objects that are based on those classes) are the nouns that your script might want to manipulate in some manner (see Table 1-1). Example 1-2 told the Finder to open a file object (basically, a file on the desktop). Objects are the data or “things” that you are interested in querying or changing when you send an Apple event to a program.

For example, a script that controls a database program usually deals with database, field, record, or cell objects. An AppleScript that sends commands to a text editor works with character, word, paragraph, and document objects.

These Apple event objects are based on classes or blueprints, such as the file class or the database class. Table 1-3 shows some of the Apple event classes from the Apple Event Registry. The operating system represents these classes internally as four-character codes.

Table 1-3. Examples of Apple Event Classes in OS 9

Class	Four-Character Code
character	'cha '
disk	'cdis'
document	'docu'
file	'file'
folder	'cfol'
paragraph	'cpar'
text	'ctxt'
window	'cwin'
word	'cwor'

A class is a blueprint or data type for a noun or object that you can manipulate with a script.

When an architect creates a blueprint for a structure, all the homes that are subsequently built off of the blueprint are the offspring of her original design. The ...