mx.data.ItemReference (Flex™ 2 Language Reference)

(Adobe^® Flex™ Data Services 2 only)

Package	mx.data
Class	public dynamic class ItemReference
Inheritance	ItemReference AsyncToken EventDispatcher Object

An ItemReference instance is returned from the DataService.getItem() and DataService.createItem() methods to provide you with a way to manage your reference to the remote object. The AsyncToken implementation that this class extends provides a list of responders to be notified of result and fault events that occur on the operation to retrieve the item (the get or the create). You can bind to the value of the result property that always maintains a reference to the managed instance. If the item is deleted in another client, the result property is set to null. If a fault occurs and the DatService instance cannot retrieve the item, the invalid property is set to true. Listen for the fault event to get more information about what caused the error.

When you want to release your reference to this managed item, you should call the ItemReference.releaseItem() method. This is similar to calling the DataService.releaseItem() method but if you are holding references to the ItemReference instance you should use this version of the releaseItem() method to ensure that you release the correct reference to the item in case you have made more than one getItem() method call to retrieve the same item from different parts of your application.

Public Properties

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	Property		Defined by
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		message : IMessage Provides access to the associated message.	AsyncToken
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		responders : Array An array of IResponder handlers that will be called when the asynchronous request completes.	AsyncToken
		result : Object The result that was returned by the associated RPC call.	AsyncToken
		valid : Boolean = false Set to `true` if the ItemReference becomes invalid either because the server faulted when trying to retrieve the item or if the retrieved item was itself null.	ItemReference
		valid : Boolean = false	ItemReference

Public Methods

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	Method		Defined by
		ItemReference(msg:IMessage)	ItemReference
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	EventDispatcher
		addResponder(responder:IResponder):void `addResponder` adds a responder to an Array of responders.	AsyncToken
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	EventDispatcher
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		hasResponder():Boolean Determines if this token has at least one `mx.rpc.IResponder` registered.	AsyncToken
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		releaseItem(clear:Boolean = true):void Releases the managed item reference retrieved with the `getItem() or createItem() method call that returned this ItemReference.`	ItemReference
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	EventDispatcher

	Event	Summary	Defined by
		propertyChange	Dispatched when a property of the channel set changes.	AsyncToken

Property detail

valid

property

public var valid:Boolean = false

Set to true if the ItemReference becomes invalid either because the server faulted when trying to retrieve the item or if the retrieved item was itself null. You can use this property to bind to your user interface controls to display status information for this item without having to listen for explicit fault events.

This property can be used as the source for data binding.

valid

property

public var valid:Boolean = false

Constructor detail

ItemReference

()

constructor

public function ItemReference(msg:IMessage)Parameters

msg:IMessage

Method detail

releaseItem

()

method

public function releaseItem(clear:Boolean = true):void

Releases the managed item reference retrieved with the getItem() or createItem() method call that returned this ItemReference. Since it is possible to have more than one ItemReference that points to the same item on the same client, this method ensures you release the proper reference.

Parameters


clear:Boolean (default = true)










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Thu Jun 22 2006, 10:21 PM GMT-07:00

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