Package	mx.core
Interface	public interface IDeferredInstance

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The IDeferredInstance interface defines the Flex deferred instance factory interface. An implementation of IDeferredInstance creates a particular instance value when the getInstance() method is first called, and returns a reference to that value when the getInstance() method is called subsequently.

The Flex compiler performs the following automatic coercions when it encounters MXML that assigns a value to a property with the IDeferredInstance type:

1. If you assign a property of type IDeferredInstance a value that is an MXML child tag representing a class, such as a component tag, the compiler creates an IDeferredInstance implementation whose getInstance() method returns an instance of the class, configured as specified in the MXML code. The following example shows this format; in this example, MyComp is a custom component that has a variable called myDeferredInstanceProperty of type IDeferredInstance. The compiler generates an IDeferredInstance1 implementation whose getInstance() method returns an instance of the Label class, with its text property set to "This is a deferred label":

             <MyComp>
                 <myDeferredInstanceProperty>
                     <Label text="This is a deferred label"/>
                 </myDeferredInstanceProperty>
             </MyComp>

2. If you assign a text string to a property of type IDeferredInstance, the compiler interprets the string as a fully qualified class name, and creates an IDeferredInstance implementation whose getInstance() method returns a new instance of the specified class. The specified class must have a constructor with no arguments. The following example shows this format; in this example, the compiler generates an IDeferredInstance1 implementation whose getInstance() method returns an instance of the MyClass class:

             <MyComp myDeferredInstanceProperty="myPackage.MyClass/>

Use the IDeferredInstance interface when an ActionScript class defers the instantiation of a property value. You cannot use IDeferredInstance if an ActionScript class requires multiple instances of the same value. In those situations, use the IFactory interface.

The states.AddChild class includes a childFactory property that is of type IDeferredInstance.

See also

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