ActionScript for Flash MX: The Definitive Guide, Second Edition

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Chapter 17: Building a Flash Form

Sending Data to the Server

To send the value of input_txt to echo.pl, we’ll create the custom functions initForm(),

shown in Example 17-1, and submitForm(), shown in Example 17-2. The initForm()

function creates one instance of the LoadVars class to send our data (

dataSender) and

another to receive echo.pl’s response (

dataReceiver). The initForm( ) function also

assigns a callback function to

dataReceiver’s onLoad( ) handler, which executes when

echo.pl’s reply arrives. The callback function displays the reply in the

response clip.

Notice that initForm( ) creates a global variable used to refer to the form’s timeline.

Hence, all our references to the

response clip are fully qualified.

The submitForm( ) function, shown in Example 17-2, gathers the data and transmits

it to echo.pl.

Example 17-1. The initForm( ) function

/*

* Function: initForm( )

* Desc: Creates LoadVars objects for sending and

* receiving data to and from the server.

* Parameters: None.

*/

function initForm ( ) {

// Create a reference to the form timeline.

_global.form_mc = this;

// Create the LoadVars objects.

// One to send...

dataSender = new LoadVars( );

// ...and one to receive.

dataReceiver = new LoadVars( );

// Assign a callback function to the dataReceiver's onLoad handler. ...