Recipe 17.3 Validating Receipt of Communication Over a Local Connection

17.3.1 Problem

You want a sending movie to receive confirmation that the communication was successfully received.

17.3.2 Solution

Configure the receiving movie to return a receipt to the sending movie.

17.3.3 Discussion

If you need to confirm that a communication was received, you can have the receiving movie send a message back to the original sending movie. Here are the steps for confirming receipt of a communication:

The following is an example of some code from a sending movie and a receiving movie.

First, the receiving movie code:

// Create the receiving code to listen on the "_myConnection" channel.
lc = new LocalConnection(  );
lc.connect("_myConnection");
lc.myMethod = function (  ) {
  // In addition to whatever other code goes in the 
  // receiving method, add this code to issue a receipt 
  // back to the sending movie over the "myConnectionReceipt" channel. 
  // The this keyword refers to the current local connection object.
  this.send("_myConnectionReceipt", "onReceipt");
};

Then, the sending movie code:

// Create the local connection object for sending over the "_myConnection" channel.
sending_lc = new LocalConnection(  );
sending_lc.send("_myConnection", "myMethod");

// Tell the local connection to listen on the "_myConnectionReceipt" channel for the
// receipt broadcast by the receiving movie.
sending_lc.connect("_myConnectionReceipt");

// Define the onReceipt(  ) method that gets called from the receiving movie.
sending_lc.onReceipt = function (  ) {
  _root.output_txt.text = "received";
};

The key point is that the name of the channel on which a local connection object listens (using connect( )) must be the same as the name of the channel over which another movie's local connection object sends a message (using send( )). Also, notice that the two movies do not communicate back and forth over the same channel. This is because a movie ignores any broadcasts over any channel to which it is also listening. So we establish two one-way channels because a single channel is not two-way in practice.

17.3.4 See Also

Recipe 17.1