Adobe® Flex® 4 Language Reference
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mx.messaging.channels 
HTTPChannel 
Packagemx.messaging.channels
Classpublic class HTTPChannel
InheritanceHTTPChannel Inheritance PollingChannel Inheritance Channel Inheritance EventDispatcher Inheritance Object
Subclasses SecureHTTPChannel, StreamingHTTPChannel

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

The HTTPChannel class provides the HTTP support for messaging. You can configure this Channel to poll the server at an interval to approximate server push. You can also use this Channel with polling disabled to send RPC messages to remote destinations to invoke their methods.

The HTTPChannel relies on network services native to Flash Player and AIR, and exposed to ActionScript by the URLLoader class. This channel uses URLLoader exclusively, and creates a new URLLoader per request.

Channels are created within the framework using the ServerConfig.getChannel() method. Channels can be constructed directly and assigned to a ChannelSet if desired.

Channels represent a physical connection to a remote endpoint. Channels are shared across destinations by default. This means that a client targetting different destinations may use the same Channel to communicate with these destinations.

When used in polling mode, this Channel polls the server for new messages based on the polling-interval-seconds property in the configuration file, and this can be changed by setting the pollingInterval property. The default value is 3 seconds. To enable polling, the channel must be connected and the polling-enabled property in the configuration file must be set to true, or the pollingEnabled property of the Channel must be set to true.



Public Properties
 PropertyDefined By
 Inheritedauthenticated : Boolean
[read-only] Indicates if this channel is authenticated.
Channel
 InheritedchannelSets : Array
[read-only] Provides access to the ChannelSets connected to the Channel.
Channel
 Inheritedconnected : Boolean
[read-only] Indicates whether this channel has established a connection to the remote destination.
Channel
 InheritedconnectTimeout : int
Provides access to the connect timeout in seconds for the channel.
Channel
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
 Inheritedendpoint : String
[read-only] Provides access to the endpoint for this channel.
Channel
 InheritedfailoverURIs : Array
Provides access to the set of endpoint URIs that this channel can attempt to failover to if the endpoint is clustered.
Channel
 Inheritedid : String
Provides access to the id of this channel.
Channel
  piggybackingEnabled : Boolean
Indicates whether this channel will piggyback poll requests along with regular outbound messages when an outstanding poll is not in progress.
HTTPChannel
  polling : Boolean
[read-only] Reports whether the channel is actively polling.
HTTPChannel
  pollingEnabled : Boolean
Indicates whether this channel is enabled to poll.
HTTPChannel
  pollingInterval : Number
Provides access to the polling interval for this Channel.
HTTPChannel
  protocol : String
[override] [read-only] Returns the protocol for this channel (http).
HTTPChannel
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
 Inheritedreconnecting : Boolean
[read-only] Indicates whether this channel is in the process of reconnecting to an alternate endpoint.
Channel
 InheritedrecordMessageSizes : Boolean
[read-only] Channel property determines the level of performance information injection - whether we inject message sizes or not.
Channel
 InheritedrecordMessageTimes : Boolean
[read-only] Channel property determines the level of performance information injection - whether we inject timestamps or not.
Channel
 InheritedrequestTimeout : int
Provides access to the default request timeout in seconds for the channel.
Channel
 Inheriteduri : String
Provides access to the URI used to create the whole endpoint URI for this channel.
Channel
Protected Properties
 PropertyDefined By
 InheritedshouldBeConnected : Boolean
[read-only] Indicates whether this channel should be connected to its endpoint.
Channel
Public Methods
 MethodDefined By
  
HTTPChannel(id:String = null, uri:String = null)
Constructor.
HTTPChannel
 Inherited
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
 Inherited
Subclasses should override this method to apply any settings that may be necessary for an individual channel.
Channel
 Inherited
connect(channelSet:ChannelSet):void
Connects the ChannelSet to the Channel.
Channel
 Inherited
Disables polling based on the number of times enablePolling() and disablePolling() have been invoked.
PollingChannel
 Inherited
Disconnects the ChannelSet from the Channel.
Channel
 Inherited
Dispatches an event into the event flow.
EventDispatcher
 Inherited
Enables polling based on the number of times enablePolling() and disablePolling() have been invoked.
PollingChannel
 Inherited
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
EventDispatcher
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Sends a CommandMessage to the server to logout if the Channel is connected.
Channel
 Inherited
Initiates a poll operation if there are consumers subscribed to this channel, and polling is enabled for this channel.
PollingChannel
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
EventDispatcher
 Inherited
send(agent:MessageAgent, message:IMessage):void
[override] Sends the specified message to its target destination.
PollingChannel
 Inherited
setCredentials(credentials:String, agent:MessageAgent = null, charset:String = null):void
Sets the credentials to the specified value.
Channel
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
 Inherited
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
EventDispatcher
Protected Methods
 MethodDefined By
 Inherited
Applies the client load balancing urls if they exists.
Channel
 Inherited
Processes a failed internal connect and dispatches the FAULT event for the channel.
Channel
 Inherited
Processes a successful internal connect and dispatches the CONNECT event for the Channel.
Channel
 Inherited
Handles a connect timeout by dispatching a ChannelFaultEvent.
Channel
 Inherited
Processes a failed internal disconnect and dispatches the FAULT event for the channel.
Channel
 Inherited
disconnectSuccess(rejected:Boolean = false):void
Processes a successful internal disconnect and dispatches the DISCONNECT event for the Channel.
Channel
 Inherited
Handles a change to the guard condition for managing initial Channel connect for the application.
Channel
 Inherited
Returns the appropriate MessageResponder for the Channel's send() method.
Channel
 Inherited
Connects the Channel to its endpoint.
Channel
 Inherited
internalDisconnect(rejected:Boolean = false):void
Disconnects the Channel from its endpoint.
Channel
 Inherited
Sends the Message out over the Channel and routes the response to the responder.
Channel
Events
 Event Summary Defined By
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.EventDispatcher
 InheritedDispatched after the channel has connected to its endpoint.Channel
 InheritedDispatched after the channel has disconnected from its endpoint.Channel
 InheritedDispatched after the channel has faulted.Channel
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.EventDispatcher
 InheritedDispatched when a channel receives a message from its endpoint.Channel
 InheritedDispatched when a property of the channel changes.Channel
Property Detail

piggybackingEnabled

property
piggybackingEnabled:Boolean

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Indicates whether this channel will piggyback poll requests along with regular outbound messages when an outstanding poll is not in progress. This allows the server to piggyback data for the client along with its response to client's message.



Implementation
    public function get piggybackingEnabled():Boolean
    public function set piggybackingEnabled(value:Boolean):void

polling

property 
polling:Boolean  [read-only]

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Reports whether the channel is actively polling.



Implementation
    public function get polling():Boolean

pollingEnabled

property 
pollingEnabled:Boolean

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Indicates whether this channel is enabled to poll.



Implementation
    public function get pollingEnabled():Boolean
    public function set pollingEnabled(value:Boolean):void

pollingInterval

property 
pollingInterval:Number

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Provides access to the polling interval for this Channel. The value is in milliseconds. This value determines how often this Channel requests messages from the server, to approximate server push.



Implementation
    public function get pollingInterval():Number
    public function set pollingInterval(value:Number):void

Throws
ArgumentError — If the pollingInterval is assigned a value of 0 or less.

protocol

property 
protocol:String  [read-only] [override]

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Returns the protocol for this channel (http).



Implementation
    override public function get protocol():String
Constructor Detail

HTTPChannel

()Constructor
public function HTTPChannel(id:String = null, uri:String = null)

Language Version: ActionScript 3.0
Product Versions: BlazeDS 4, LiveCycle Data Services 3
Runtime Versions: Flash Player 9, AIR 1.1

Constructor.

Parameters
id:String (default = null) — The id of this Channel.
 
uri:String (default = null) — The uri for this Channel.