XMLSocket


Object
    |
    +-XMLSocket

public class XMLSocket
extends Object

The XMLSocket class implements client sockets that let the computer running Flash Player communicate with a server computer identified by an IP address or domain name. The XMLSocket class is useful for client-server applications that require low latency, such as real-time chat systems. A traditional HTTP-based chat solution frequently polls the server and downloads new messages using an HTTP request. In contrast, an XMLSocket chat solution maintains an open connection to the server, which lets the server immediately send incoming messages without a request from the client. To use the XMLSocket class, the server computer must run a daemon that understands the protocol used by the XMLSocket class. The protocol is described in the following list:

XML messages are sent over a full-duplex TCP/IP stream socket connection.
Each XML message is a complete XML document, terminated by a zero (0) byte.
An unlimited number of XML messages can be sent and received over a single XMLSocket connection.

The following restrictions apply to how and where an XMLSocket object can connect to the server:

The XMLSocket.connect() method can connect only to TCP port numbers greater than or equal to 1024. One consequence of this restriction is that the server daemons that communicate with the XMLSocket object must also be assigned to port numbers greater than or equal to 1024. Port numbers below 1024 are often used by system services such as FTP, Telnet, and HTTP, so XMLSocket objects are barred from these ports for security reasons. The port number restriction limits the possibility that these resources will be inappropriately accessed and abused.
The XMLSocket.connect() method can connect only to computers in the same domain where the SWF file resides. This restriction does not apply to SWF files running off a local disk. (This restriction is identical to the security rules for loadVariables(), XML.sendAndLoad(), and XML.load().) To connect to a server daemon running in a domain other than the one where the SWF resides, you can create a security policy file on the server that allows access from specific domains.

Setting up a server to communicate with the XMLSocket object can be challenging. If your application does not require real-time interactivity, use the loadVariables() function, or Flash HTTP-based XML server connectivity (XML.load(), XML.sendAndLoad(), XML.send()), instead of the XMLSocket class. To use the methods of the XMLSocket class, you must first use the constructor, new XMLSocket, to create an XMLSocket object.

Availability: ActionScript 1.0; Flash Player 5

Property summary

Properties inherited from class Object

constructor, __proto__, prototype, __resolve

Event summary

Event	Description
onClose `= function() {}`	Invoked only when an open connection is closed by the server.
onConnect `= function(success:Boolean) {}`	Invoked by Flash Player when a connection request initiated through `XMLSocket.connect()` has succeeded or failed.
onData `= function(src:String) {}`	Invoked when a message has been downloaded from the server, terminated by a zero (0) byte.
onXML `= function(src:XML) {}`	Invoked by Flash Player when the specified XML object containing an XML document arrives over an open XMLSocket connection.

Constructor summary

Signature	Description
XMLSocket`()`	Creates a new XMLSocket object.

Method summary

Modifiers	Signature	Description
	close`() : Void`	Closes the connection specified by XMLSocket object.
	connect`(url:String, port:Number) : Boolean`	Establishes a connection to the specified Internet host using the specified TCP port (must be 1024 or higher), and returns `true` or `false,` depending on whether a connection is successfully established.
	send`(data:Object) : Void`	Converts the XML object or data specified in the `object` parameter to a string and transmits it to the server, followed by a zero (0) byte.

Methods inherited from class Object

addProperty, hasOwnProperty, isPropertyEnumerable, isPrototypeOf, registerClass, toString, unwatch, valueOf, watch

Version 8

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Current page: http://livedocs.adobe.com/flash/8/main/00002906.html