mx.messaging.MultiTopicConsumer - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.messaging
Class	public class MultiTopicConsumer
Inheritance	MultiTopicConsumer AbstractConsumer MessageAgent EventDispatcher Object

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Like a Consumer, a MultiTopicConsumer subscribes to a destination with a single clientId and delivers messages to a single event handler. Unlike a Consumer it lets you register subscriptions for a list of subtopics and selector expressions at the same time from a single message handler. Where Consumer has subtopic and selector properties, this component has an addSubscription(subtopic, selector) method you use to add a new subscription to the existing set of subscriptions. Alternatively, you can populate the subscriptions property with a list of SubscriptionInfo instances that define the subscriptions for this destination.

Like the regular Consumer, the MultiTopicConsumer sends subscribe and unsubscribe messages which generate a MessageAckEvent or MessageFaultEvent depending upon whether the operation was successful or not. Once subscribed, a MultiTopicConsumer dispatches a MessageEvent for each message it receives.

MXML Syntax expanded

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The <mx:MultiTopicConsumer> tag has these properties:

   <mx:Consumer
    Properties
    subscriptions=""an empty ArrayCollection of SubscriptionInfo objects"
    resubscribeAttempts="5"
    resubscribeInterval="5000"
    timestamp="No default."
  />

Public Properties

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	Property		Defined By
		authenticated : Boolean [read-only] Indicates if this MessageAgent is using an authenticated connection to its destination.	MessageAgent
		channelSet : ChannelSet Provides access to the ChannelSet used by the MessageAgent.	MessageAgent
		clientId : String [read-only] Provides access to the client id for the MessageAgent.	MessageAgent
		connected : Boolean [read-only] Indicates whether this MessageAgent is currently connected to its destination via its ChannelSet.	MessageAgent
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		destination : String Provides access to the destination for the MessageAgent.	MessageAgent
		maxFrequency : uint Determines the maximum number of messages per second the Consumer wants to receive.	AbstractConsumer
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		requestTimeout : int Provides access to the request timeout in seconds for sent messages.	MessageAgent
		resubscribeAttempts : int The number of resubscribe attempts that the Consumer makes in the event that the destination is unavailable or the connection to the destination fails.	AbstractConsumer
		resubscribeInterval : int The number of milliseconds between resubscribe attempts.	AbstractConsumer
		subscribed : Boolean [read-only] Indicates whether the Consumer is currently subscribed.	AbstractConsumer
		subscriptions : ArrayCollection Stores an Array of SubscriptionInfo objects.	MultiTopicConsumer
		timestamp : Number Contains the timestamp of the most recent message this Consumer has received.	AbstractConsumer

Protected Properties

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	Property		Defined By
		_shouldBeSubscribed : Boolean Flag indicating whether this consumer should be subscribed or not.	AbstractConsumer

Public Methods

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	Method		Defined By
		MultiTopicConsumer() Constructor.	MultiTopicConsumer
		acknowledge(ackMsg:AcknowledgeMessage, msg:IMessage):void Invoked by a MessageResponder upon receiving a result for a sent message.	MessageAgent
		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
		addSubscription(subtopic:String = null, selector:String = null, maxFrequency:uint = 0):void This is a convenience method for adding a new subscription.	MultiTopicConsumer
		channelConnectHandler(event:ChannelEvent):void Handles a CONNECT ChannelEvent.	MessageAgent
		channelDisconnectHandler(event:ChannelEvent):void Handles a DISCONNECT ChannelEvent.	MessageAgent
		channelFaultHandler(event:ChannelFaultEvent):void Handles a ChannelFaultEvent.	MessageAgent
		disconnect():void [override] Disconnects the Consumer from its remote destination.	AbstractConsumer
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		fault(errMsg:ErrorMessage, msg:IMessage):void Invoked by a MessageResponder upon receiving a fault for a sent message.	MessageAgent
		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
		hasPendingRequestForMessage(msg:IMessage):Boolean Returns true if there are any pending requests for the passed in message.	MessageAgent
		initialized(document:Object, id:String):void Called after the implementing object has been created and all properties specified on the tag have been assigned.	MessageAgent
		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
		logout():void Logs the MessageAgent out from its remote destination.	MessageAgent
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		receive(timestamp:Number = 0):void Requests any messages that are queued for this Consumer on the server.	AbstractConsumer
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		removeSubscription(subtopic:String = null, selector:String = null):void This method removes the subscription specified by the subtopic and selector.	MultiTopicConsumer
		setCredentials(username:String, password:String, charset:String = null):void Sets the credentials that the MessageAgent uses to authenticate to destinations.	MessageAgent
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		setRemoteCredentials(username:String, password:String, charset:String = null):void Sets the remote credentials that will be passed through to the remote destination for authenticating to secondary systems.	MessageAgent
		subscribe(clientId:String = null):void Subscribes to the remote destination.	AbstractConsumer
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		unsubscribe(preserveDurable:Boolean = false):void Unsubscribes from the remote destination.	AbstractConsumer
		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

Protected Methods

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	Method		Defined By
		buildSubscribeMessage():CommandMessage [override] Returns a subscribe message.	MultiTopicConsumer
		buildUnsubscribeMessage(preserveDurable:Boolean):CommandMessage [override] Returns an unsubscribe mesage.	MultiTopicConsumer
		initChannelSet(message:IMessage):void Used to automatically initialize the channelSet property for the MessageAgent before it connects for the first time.	MessageAgent
		internalSend(message:IMessage, waitForClientId:Boolean = true):void Sends a Message from the MessageAgent to its destination using the agent's ChannelSet.	MessageAgent
		reAuthorize(msg:IMessage):void This function should be overriden by sublasses to implement re-authorization due to server session time-out behavior specific to them.	MessageAgent

Events

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	Summary	Defined By
acknowledge	Dispatched when an acknowledge message is received for a sent message.	MessageAgent
activate	[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.	EventDispatcher
channelConnect	Dispatched when the underlying Channel the MessageAgent is using connects.	MessageAgent
channelDisconnect	Dispatched when the underlying Channel the MessageAgent is using disconnects.	MessageAgent
channelFault	Dispatched when the underlying Channel the MessageAgent is using faults.	MessageAgent
deactivate	[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.	EventDispatcher
fault	Dispatched when a message fault occurs.	MessageAgent
message	Dispatched when a message is received by the Consumer.	MultiTopicConsumer
propertyChange	Dispatched when the connected property of the MessageAgent changes.	MessageAgent

Property Detail

subscriptions

property

subscriptions:ArrayCollection

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Stores an Array of SubscriptionInfo objects. Each subscription contains a subtopic and a selector each of which can be null. A subscription with a non-null subtopic restricts the subscription to messages delivered with only that subtopic. If a subtopic is null, it uses the selector with no subtopic. If the selector and the subtopic is null, the subscription receives any messages targeted at the destination with no subtopic. The subtopic can contain a wildcard specification.

Before a call to the subscribe() method, this property can be set with no side effects. After the MultiTopicConsumer has subscribed to its destination, changing this value has the side effect of updating the MultiTopicConsumer's subscription to include any new subscriptions and remove any subscriptions you deleted from the ArrayCollection.

The remote destination must understand the value of the selector expression.

This property can be used as the source for data binding. When this property is modified, it dispatches the propertyChange event.

Implementation
public function get subscriptions():ArrayCollection
public function set subscriptions(value:ArrayCollection):void

Constructor Detail

MultiTopicConsumer

()

Constructor

public function MultiTopicConsumer()

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constructor.

Example ( How to use this example )

       function initConsumer():void
       {
           var consumer:Consumer = new MultiTopicConsumer();
           consumer.destination = "NASDAQ";
           consumer.addEventListener(MessageEvent.MESSAGE, messageHandler);
           consumer.addSubscription("myStock1", "operation IN ('BID', 'Ask')");
           consumer.addSubscription("myStock2", "operation IN ('BID', 'Ask')");
           consumer.subscribe();
       }
     
       function messageHandler(event:MessageEvent):void
       {
           var msg:IMessage = event.message;
           var info:Object = msg.body;
           trace("-App recieved message: " + msg.toString());
       }

Method Detail

addSubscription

()

method

public function addSubscription(subtopic:String = null, selector:String = null, maxFrequency:uint = 0):void

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

This is a convenience method for adding a new subscription. It just creates a new SubscriptionInfo object and adds it to the subscriptions property. To call this method, you provide the subtopic and selector string for the new subscription. If the subtopic is null, the subscription applies to messages which do not have a subtopic set in the producer. If the selector string is null, all messages sent which match the subtopic string are received by this consumer.

Parameters

	`subtopic:String` (default = `null`) — The subtopic for the new subscription.

	`selector:String` (default = `null`) — The selector for the new subscription.

	`maxFrequency:uint` (default = `0`) — The maximum number of messages per second the Consumer wants to receive for the subscription. Note that this value overwrites the Consumer wide maxFrequency.

buildSubscribeMessage

()

method

override protected function buildSubscribeMessage():CommandMessage

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns a subscribe message.

Returns

CommandMessage — The subscribe CommandMessage.

buildUnsubscribeMessage

()

method

override protected function buildUnsubscribeMessage(preserveDurable:Boolean):CommandMessage

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns an unsubscribe mesage.

Parameters

preserveDurable:Boolean — When true, durable JMS subscriptions are not destroyed, allowing consumers to later resubscribe and receive missed messages.

Returns

CommandMessage — The unsubscribe CommandMessage.

removeSubscription

()

method

public function removeSubscription(subtopic:String = null, selector:String = null):void

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

This method removes the subscription specified by the subtopic and selector.

Parameters

	`subtopic:String` (default = `null`) — The subtopic for the subscription.

	`selector:String` (default = `null`) — The selector for the subscription.

Event Detail

message

Event

Event Object Type: mx.messaging.events.MessageEvent
property MessageEvent.type = mx.messaging.events.MessageEvent.MESSAGE

Language Version:

ActionScript 3.0

Product Versions:

BlazeDS 4, LiveCycle Data Services 3

Runtime Versions:

Flash Player 9, AIR 1.1

Dispatched when a message is received by the Consumer.

The MESSAGE event type; dispatched upon receipt of a message.

The value of this constant is "message".

The properties of the event object have the following values:

Property	Value
`bubbles`	false
`cancelable`	false
`currentTarget`	The Object that defines the event listener that handles the event. For example, if you use `myButton.addEventListener()` to register an event listener, myButton is the value of the `currentTarget`.
`message`	The message associated with this event.
`target`	The Object that dispatched the event; it is not always the Object listening for the event. Use the `currentTarget` property to always access the Object listening for the event.