LocalConnection  - AS3

Indicates the object on which callback methods are invoked. The default object is this, the local connection being created. You can set the client property to another object, and callback methods are invoked on that other object.

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A string representing the domain of the location of the current file.

In content running in the application security sandbox in Adobe AIR (content installed with the AIR application), the runtime uses the string app# followed by the application ID for the AIR application (defined in the application descriptor file) in place of the superdomain. For example a connectionName for an application with the application ID com.example.air.MyApp connectionName resolves to "app#com.example.air.MyApp:connectionName".

In SWF files published for Flash Player 9 or later, the returned string is the exact domain of the file, including subdomains. For example, if the file is located at www.adobe.com, this command returns "www.adobe.com".

If the current file is a local file residing on the client computer running in Flash Player, this command returns "localhost".

The most common ways to use this property are to include the domain name of the sending LocalConnection object as a parameter to the method you plan to invoke in the receiving LocalConnection object, or to use it with LocalConnection.allowDomain() to accept commands from a specified domain. If you are enabling communication only between LocalConnection objects that are located in the same domain, you probably don't need to use this property.

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The isSupported property is set to true if the LocalConnection class is supported on the current platform, otherwise it is set to false.

Creates a LocalConnection object. You can use LocalConnection objects to enable communication between different files that are running on the same client computer.

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Specifies one or more domains that can send LocalConnection calls to this LocalConnection instance.

You cannot use this method to let files hosted using a secure protocol (HTTPS) allow access from files hosted in nonsecure protocols; you must use the allowInsecureDomain() method instead.

You may want to use this method so that a child file from a different domain can make LocalConnection calls to the parent file, without knowing the final domain from which the child file will come. This can happen, for example, when you use load-balancing redirects or third-party servers. In this situation, you can use the url property of the LoaderInfo object used with the load, to get the domain to use with the allowDomain() method. For example, if you use a Loader object to load a child file, once the file is loaded, you can check the contentLoaderInfo.url property of the Loader object, and parse the domain out of the full URL string. If you do this, make sure that you wait until the file is loaded, because the contentLoaderInfo.url property will not have its final, correct value until the file is completely loaded.

The opposite situation can also occur: you might create a child file that wants to accept LocalConnection calls from its parent but doesn't know the domain of its parent. In this situation, implement this method by checking whether the domain argument matches the domain of the loaderInfo.url property in the loaded file. Again, you must parse the domain out of the full URL from loaderInfo.url. In this situation, you don't have to wait for the parent file to load; the parent will already be loaded by the time the child loads.

When using this method, consider the Flash Player security model. By default, a LocalConnection object is associated with the sandbox of the file that created it, and cross-domain calls to LocalConnection objects are not allowed unless you call the LocalConnection.allowDomain() method in the receiving file. However, in Adobe AIR, content in the application security sandbox (content installed with the AIR application) are not restricted by these security limitations.

For more information related to security, see the Flash Player Developer Center Topic: Security.

Note: The allowDomain() method has changed from the form it had in ActionScript 1.0 and 2.0. In those earlier versions, allowDomain was a callback method that you implemented. In ActionScript 3.0, allowDomain() is a built-in method of LocalConnection that you call. With this change, allowDomain() works in much the same way as flash.system.Security.allowDomain().

Parameters

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Specifies one or more domains that can send LocalConnection calls to this LocalConnection object.

The allowInsecureDomain() method works just like the allowDomain() method, except that the allowInsecureDomain() method additionally permits SWF files from non-HTTPS origins to send LocalConnection calls to files from HTTPS origins. This difference is meaningful only if you call the allowInsecureDomain() method from a file that was loaded using HTTPS. You must call the allowInsecureDomain() method even if you are crossing a non-HTTPS/HTTPS boundary within the same domain; by default, LocalConnection calls are never permitted from non-HTTPS files to HTTPS files, even within the same domain.

Calling allowInsecureDomain() is not recommended, because it can compromise the security offered by HTTPS. When you load a file over HTTPS, you can be reasonably sure that the file will not be tampered with during delivery over the network. If you then permit a non-HTTPS file to make LocalConnection calls to the HTTPS file, you are accepting calls from a file that may in fact have been tampered with during delivery. This generally requires extra vigilance because you cannot trust the authenticity of LocalConnection calls arriving at your HTTPS file.

By default, files hosted using the HTTPS protocol can be accessed only by other files hosted using the HTTPS protocol. This implementation maintains the integrity provided by the HTTPS protocol.

Using this method to override the default behavior is not recommended, because it compromises HTTPS security. However, you might need to do so, for example, if you need to permit access to HTTPS SWF files published for Flash Player 9 or later from HTTP files SWF published for Flash Player 6 or earlier.

For more information related to security, see the Flash Player Developer Center Topic: Security.

Parameters

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Closes (disconnects) a LocalConnection object. Issue this command when you no longer want the object to accept commands — for example, when you want to issue a connect() command using the same connectionName parameter in another SWF file.

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Prepares a LocalConnection object to receive commands that are sent from a send() command (from the sending LocalConnection object). The object used with the connect() method is called the receiving LocalConnection object. The receiving and sending objects must be running on the same client computer.

To avoid a race condition, define the methods attached to the receiving LocalConnection object before calling this method, as shown in the LocalConnection class example.

By default, the connectionName argument is resolved into a value of "superdomain:connectionName", where superdomain is the superdomain of the file that contains the connect() command. For example, if the file that contains the receiving LocalConnection object is located at www.someDomain.com, connectionName resolves to "someDomain.com:connectionName". (If a file running in Flash Player is located on the client computer, the value assigned to superdomain is "localhost".)

In content running in the application security sandbox in Adobe AIR (content installed with the AIR application), the runtime uses the string app# followed by the application ID for the AIR application (defined in the application descriptor file) in place of the superdomain. For example a connectionName for an application with the application ID com.example.air.MyApp connectionName resolves to "app#com.example.air.MyApp:connectionName".

Also by default, Flash Player lets the receiving LocalConnection object accept commands only from sending LocalConnection objects whose connection name also resolves into a value of "superdomain:connectionName". In this way, Flash Player makes it simple for files that are located in the same domain to communicate with each other.

If you are implementing communication only between files in the same domain, specify a string for connectionName that does not begin with an underscore (_) and that does not specify a domain name (for example, "myDomain:connectionName"). Use the same string in the connect(connectionName) method.

If you are implementing communication between files in different domains, specifying a string for connectionName that begins with an underscore (_) makes the file with the receiving LocalConnection object more portable between domains. Here are the two possible cases:

• If the string for connectionNamedoes not begin with an underscore (_), a prefix is added with the superdomain and a colon (for example, "myDomain:connectionName"). Although this ensures that your connection does not conflict with connections of the same name from other domains, any sending LocalConnection objects must specify this superdomain (for example, "myDomain:connectionName"). If the file with the receiving LocalConnection object is moved to another domain, the player changes the prefix to reflect the new superdomain (for example, "anotherDomain:connectionName"). All sending LocalConnection objects would have to be manually edited to point to the new superdomain.
• If the string for connectionNamebegins with an underscore (for example, "_connectionName"), a prefix is not added to the string. This means that the receiving and sending LocalConnection objects use identical strings for connectionName. If the receiving object uses allowDomain() to specify that connections from any domain will be accepted, the file with the receiving LocalConnection object can be moved to another domain without altering any sending LocalConnection objects.

For more information, see the discussion in the class overview and the discussion of connectionName in send(), and also the allowDomain() and domain entries.

Note: Colons are used as special characters to separate the superdomain from the connectionName string. A string for connectionName that contains a colon is not valid.

When you use this method , consider the Flash Player security model. By default, a LocalConnection object is associated with the sandbox of the file that created it, and cross-domain calls to LocalConnection objects are not allowed unless you call the LocalConnection.allowDomain() method in the receiving file. You can prevent a file from using this method by setting the allowNetworking parameter of the the object and embed tags in the HTML page that contains the SWF content. However, in Adobe AIR, content in the application security sandbox (content installed with the AIR application) are not restricted by these security limitations.

For more information related to security, see the Flash Player Developer Center Topic: Security.

Parameters

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Invokes the method named methodName on a connection that was opened with the connect(connectionName) method (in the receiving LocalConnection object). The object used with the send() method is called the sending LocalConnection object. The SWF files that contain the sending and receiving objects must be running on the same client computer.

There is a 40 kilobyte limit to the amount of data you can pass as parameters to this command. If send() throws an ArgumentError but your syntax is correct, try dividing the send() requests into multiple commands, each with less than 40K of data.

As discussed in the connect() entry, the current superdomain in added to connectionName by default. If you are implementing communication between different domains, you need to define connectionName in both the sending and receiving LocalConnection objects in such a way that the current superdomain is not added to connectionName. You can do this in one of the following two ways:

• Use an underscore (_) at the beginning of connectionName in both the sending and receiving LocalConnection objects. In the file that contains the receiving object, use LocalConnection.allowDomain() to specify that connections from any domain will be accepted. This implementation lets you store your sending and receiving files in any domain.
• Include the superdomain in connectionName in the sending LocalConnection object — for example, myDomain.com:myConnectionName. In the receiving object, use LocalConnection.allowDomain() to specify that connections from the specified superdomain will be accepted (in this case, myDomain.com) or that connections from any domain will be accepted.

Note: You cannot specify a superdomain in connectionName in the receiving LocalConnection object — you can do this in only the sending LocalConnection object.

When you use this method , consider the Flash Player security model. By default, a LocalConnection object is associated with the sandbox of the file that created it, and cross-domain calls to LocalConnection objects are not allowed unless you call the LocalConnection.allowDomain() method in the receiving file. For SWF content running in the browser, ou can prevent a file from using this method by setting the allowNetworking parameter of the the object and embed tags in the HTML page that contains the SWF content. However, in Adobe AIR, content in the application security sandbox (content installed with the AIR application) are not restricted by these security limitations.

For more information related to security, see the Flash Player Developer Center Topic: Security.

Parameters

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Dispatched when an exception is thrown asynchronously — that is, from native asynchronous code.

This event has the following properties:

Dispatched if a call to LocalConnection.send() attempts to send data to a different security sandbox.

This event has the following properties:

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Dispatched when a LocalConnection object reports its status. If LocalConnection.send() is successful, the value of the status event object's level property is "status"; if the call fails, the level property is "error". If the receiving file refuses the connection, the call can fail without notification to the sending file.

This event has the following properties:

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In the LocalConnectionSenderExample SWF file, a LocalConnection instance is created, and when the button is pressed the call() method is used to call the method named lcHandler in the SWF file with the connection name "myConnection," passing the contents of the TextField as a parameter.

In the LocalConnectionReceiverExample SWF file, a LocalConnection instance is created and the connect() method is called to designate this SWF file as the recipient of messages that are addressed to the connection named "myConnection." In addition, this class includes a public method named lcHandler(); this method is the one that is called by the LocalConnectionSenderExample SWF file. When it's called, the text that is passed in as a parameter is appended to the TextField on the Stage.

Note: To test the example, both SWF files must be loaded on the same computer simultaneously.

// Code in LocalConnectionSenderExample.as
package {
    import flash.display.Sprite;
    import flash.events.MouseEvent;
    import flash.net.LocalConnection;
    import flash.text.TextField;
    import flash.text.TextFieldType;
    import flash.events.StatusEvent;
    import flash.text.TextFieldAutoSize;

    public class LocalConnectionSenderExample extends Sprite {
        private var conn:LocalConnection;
        
        // UI elements
        private var messageLabel:TextField;
        private var message:TextField;
        private var sendBtn:Sprite;
        
        public function LocalConnectionSenderExample() {
            buildUI();
            sendBtn.addEventListener(MouseEvent.CLICK, sendMessage);
            conn = new LocalConnection();
            conn.addEventListener(StatusEvent.STATUS, onStatus);
        }
        
        private function sendMessage(event:MouseEvent):void {
            conn.send("myConnection", "lcHandler", message.text);
        }
        
        private function onStatus(event:StatusEvent):void {
            switch (event.level) {
                case "status":
                    trace("LocalConnection.send() succeeded");
                    break;
                case "error":
                    trace("LocalConnection.send() failed");
                    break;
            }
        }
        
        private function buildUI():void {
            const hPadding:uint = 5;
            // messageLabel
            messageLabel = new TextField();
            messageLabel.x = 10;
            messageLabel.y = 10;
            messageLabel.text = "Text to send:";
            messageLabel.autoSize = TextFieldAutoSize.LEFT;
            addChild(messageLabel);
            
            // message
            message = new TextField();
            message.x = messageLabel.x + messageLabel.width + hPadding;
            message.y = 10;
            message.width = 120;
            message.height = 20;
            message.background = true;
            message.border = true;
            message.type = TextFieldType.INPUT;
            addChild(message);
            
            // sendBtn
            sendBtn = new Sprite();
            sendBtn.x = message.x + message.width + hPadding;
            sendBtn.y = 10;
            var sendLbl:TextField = new TextField();
            sendLbl.x = 1 + hPadding;
            sendLbl.y = 1;
            sendLbl.selectable = false;
            sendLbl.autoSize = TextFieldAutoSize.LEFT;
            sendLbl.text = "Send";
            sendBtn.addChild(sendLbl);
            sendBtn.graphics.lineStyle(1);
            sendBtn.graphics.beginFill(0xcccccc);
            sendBtn.graphics.drawRoundRect(0, 0, (sendLbl.width + 2 + hPadding + hPadding), (sendLbl.height + 2), 5, 5);
            sendBtn.graphics.endFill();
            addChild(sendBtn);
        }
    }
}