Object.addproperty() - MACROMEDIA FLASH MX 2004-ACTIONSCRIPT LANGUAGE Reference

Object.addProperty()

Availability
Flash Player 6. In ActionScript 2.0 classes, you can use
Usage
myObject.addProperty(prop:String, getFunc:Function, setFunc:Function) :
Boolean
Parameters
A string; the name of the object property to create.
prop
The function that is invoked to retrieve the value of the property; this parameter is a
getFunc
Function object.
The function that is invoked to set the value of the property; this parameter is a
setFunc
Function object. If you pass the value
Returns
A Boolean value:
Description
Method; creates a getter/setter property. When Flash reads a getter/setter property, it invokes the
function, and the function's return value becomes the value of
get
getter/setter property, it invokes the
property with the given name already exists, the new property overwrites it.
A "get" function is a function with no parameters. Its return value can be of any type. Its type can
change between invocations. The return value is treated as the current value of the property.
A "set" function is a function that takes one parameter, which is the new value of the property. For
example, if property
of type number. The return value of the set function is ignored.
1
You can add getter/setter properties to prototype objects. If you add a getter/setter property to a
prototype object, all object instances that inherit the prototype object inherit the getter/setter
property. This makes it possible to add a getter/setter property in one location, the prototype
object, and have it propagate to all instances of a class (similar to adding methods to prototype
objects). If a get/set function is invoked for a getter/setter property in an inherited prototype
object, the reference passed to the get/set function is the originally referenced object—not the
prototype object.
If invoked incorrectly,
describes errors that can occur:
Error condition
is not a valid property name; for example, an
prop
empty string.
662 Chapter 2: ActionScript Language Reference
null
if the property is successfully created;
true
set
is assigned by the statement
x
Object.addProperty()
get or set
for this parameter, the property is read-only.
false
function and passes it the new value as a parameter. If a
, the set function is passed the parameter
x = 1
can fail with an error. The following table
What happens
Returns
false
instead of this method.
otherwise.
. When Flash writes a
prop
and the property is not added.