Adobe® Flex® 4 Language Reference
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air.net 
URLMonitor 
Packageair.net
Classpublic class URLMonitor
InheritanceURLMonitor Inheritance ServiceMonitor Inheritance EventDispatcher Inheritance Object

Runtime Versions: AIR 1.0

The URLMonitor class monitors availablity of an HTTP- or HTTPS-based service.

This class is included in the ServiceMonitor.swc file. Adobe® Flash® Builder™ loads this class automatically when you create a project for Adobe® AIR®. The Adobe® Flex® SDK also includes this servicemonitor.swc file, which you should include when compiling the application if you are using the Flex SDK.

In Adobe® Flash® CS3 Professional, this class is included in the ServiceMonitorShim.swc file. To use classes in the air.net package , you must first drag the ServiceMonitorShim component from the Components panel to the Library and then add the following import statement to your ActionScript 3.0 code:

import air.net.*;

To use air.net package in Adobe® Flash® CS4 Professional:

  1. Select the File > Publish Settings command.
  2. In the Flash panel, click the Settings button for ActionScript 3.0. Select Library Path.
  3. Click the Browse to SWC File button. Browse to Adobe Flash CS4/AIK1.1/frameworks/libs/air/servicemoniter.swc file in the Adobe Flash CS4 installation folder.
  4. Click the OK button.
  5. Add the following import statement to your ActionScript 3.0 code: import air.net.*;



Public Properties
 PropertyDefined By
  AIR-only acceptableStatusCodes : Array
The numeric status codes representing a successful result.
URLMonitor
 InheritedAIR-only available : Boolean
Whether the service is currently considered "available." The initial value is false until either a status check sets the property to true or the property is initialized to true explicitly. Typically, this property is set by the checkStatus() implementation in a subclass or specializer, but if the application has independent information about a service's availability (for example, a request just succeeded or failed), the property can be set explicitly.
ServiceMonitor
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
 InheritedAIR-only lastStatusUpdate : Date
[read-only] The time of the last status update.
ServiceMonitor
 InheritedAIR-only pollInterval : Number
The interval, in milliseconds, for polling the server.
ServiceMonitor
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
 InheritedAIR-only running : Boolean
[read-only] Whether the monitor has been started.
ServiceMonitor
  AIR-only urlRequest : URLRequest
[read-only] The URLRequest object representing the probe request.
URLMonitor
Public Methods
 MethodDefined By
  
AIR-only URLMonitor(urlRequest:URLRequest, acceptableStatusCodes:Array = null)
Creates a URLMonitor Object for a specified HTTP- or HTTPS-based service.
URLMonitor
 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
Dispatches an event into the event flow.
EventDispatcher
 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
AIR-only makeJavascriptSubclass(constructorFunction:Object):void
[static] Adds public ServiceMonitor methods to a JavaScript constructor function's prototype.
ServiceMonitor
 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
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Starts the service monitor.
ServiceMonitor
 Inherited
Stops monitoring the service.
ServiceMonitor
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
  
[override] Returns the string representation of the specified object.
URLMonitor
 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
  
[override] Attempts to load content from a URL in the background, to check for a returned HTTP status code.
URLMonitor
Events
 Event Summary Defined By
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.EventDispatcher
 Inherited[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.EventDispatcher
 InheritedIndicates that the service status has changed.ServiceMonitor
Property Detail
AIR-only 

acceptableStatusCodes

property
acceptableStatusCodes:Array

Runtime Versions: AIR 1.0

The numeric status codes representing a successful result.



Implementation
    public function get acceptableStatusCodes():Array
    public function set acceptableStatusCodes(value:Array):void
AIR-only 

urlRequest

property 
urlRequest:URLRequest  [read-only]

Runtime Versions: AIR 1.0

The URLRequest object representing the probe request.



Implementation
    public function get urlRequest():URLRequest
Constructor Detail
AIR-only 

URLMonitor

()Constructor
public function URLMonitor(urlRequest:URLRequest, acceptableStatusCodes:Array = null)

Runtime Versions: AIR 1.0

Creates a URLMonitor Object for a specified HTTP- or HTTPS-based service.

After creating a URLMonitor, the caller should call the start() method to begin monitoring the status of the service.

As with the Timer object, the caller should maintain a reference to the URLMonitor object. Otherwise the runtime could delete the object, thereby ending the monitoring.

A URLRequest parameter specifies the probe request for polling the server. Typically, the request method will be either "GET" or "HEAD".

Parameters
urlRequest:URLRequest — The URLRequest object representing a probe request for polling the server.
 
acceptableStatusCodes:Array (default = null) — An array of numeric status codes listing the codes that represent a successful result.

If you do not specify a value for the acceptableStatusCodes property, the following status codes will be recognized as successful responses:

  • 200 (OK)
  • 202 (Accepted)
  • 204 (No content
  • 205 (Reset content)
  • 206 (Partial content, in response to request with a Range header)
Method Detail

AIR-only checkStatus

()method
override protected function checkStatus():void

Runtime Versions: AIR 1.0

Attempts to load content from a URL in the background, to check for a returned HTTP status code.

If it receives a status code that is listed in the acceptableStatusCodes property, the available property will be set to true. If it receives a status code that is not in the acceptableStatusCodes list, or if there is a security error or I/O error, the available property will be set to false.

AIR-only toString

()method 
override public function toString():String

Runtime Versions: AIR 1.0

Returns the string representation of the specified object.

Note: Methods of the Object class are dynamically created on Object's prototype. To redefine this method in a subclass of Object, do not use the override keyword. For example, a subclass of Object implements function toString():String instead of using an override of the base class.

Returns
String — A string representation of the object.