Language Guide

CHAPTER 8
Handlers
242 Command Handlers
SYNTAX
The syntax for a command handler definition is
( on | to ) commandName ¬
[ [ of ] directParameterVariable ] ¬
[ given label:paramVariable [, label:paramVariable ]...]
[ global variable [, variable ]...]
[ local variable [, variable ]...]
[ statement ]...
end [ commandName ]
where
commandName (an identifier) is a command name.
directParameterVariable (an identifier) is a parameter variable for the actual
value of the direct parameter. You use this parameter variable to refer to the
direct parameter in the body of the subroutine. If it is included, directParameter
must be listed immediately after the command name. The word of before
directParameter is optional.
label is the parameter label for one of the parameters of the command being
handled. The label given is optional.
paramVariable (an identifier) is a parameter variable for the actual value of the
parameter. You use this identifier to refer to the parameter in the body of
the handler.
variable is an identifier for either a global or local variable that can be used in
the handler. The scope of a local variable is the handler. You cannot refer to a
local variable outside the handler. The scope of a global variable can extend to
any other part of the script, including other handlers and script objects. For
detailed information about the scope of local and global variables, see “Scope
of Script Variables and Properties,” which begins on page 252.
statement is any AppleScript statement.
NOTES
The statements in a command handler can include a Continue statement,
which passes the command to the application’s default handler for that
command. This allows you to invoke an application’s default behavior for a
command from within a command handler. For more information, see “The
Continue Statement,” which begins on page 277.