Language Guide

CHAPTER 9
Script Objects
Defining Script Objects 267
Defining Script Objects 9
Each script object definition begins with the keyword script, followed by an
optional variable name, and ends with the keyword end (or end script).
The statements in between can be any combination of property definitions,
handler definitions, and other AppleScript statements.
The syntax of a script object definition is
script [ scriptObjectVariable ]
[( property | prop ) propertyLabel : initialValue ]...
[ handlerDefinition ]...
[ statement ]...
end [script]
where
scriptObjectVariable is a variable identifier. If you include scriptObjectVariable,
AppleScript stores the script object in a variable. You can use the variable
identifier to refer to the script object elsewhere in the script.
propertyLabel is an identifier for a property. Properties are characteristics that
are identified by unique labels. They are similar to instance variables in
object-oriented programming.
initialValue is the value that is assigned to the property each time the script
object is initialized. Script objects are initialized when the scripts or handlers
that contain them are run. initialValue is required in property definitions.
handlerDefinition is a handler for a user-defined or system command. The
handlers within a script object definition determine which commands the script
object can respond to. Script object definitions can include handlers for user-
defined commands (subroutines) or for system or application commands.
Handlers in script objects are similar to methods in object-oriented program-
ming. For a detailed description of the syntax of handler definitions, refer to
Chapter 8, “Handlers.”
statement is any AppleScript statement. Statements other than handler and
property definitions are treated as if they were part of a handler definition
for the Run command; they are executed when a script object receives the
Run command.