ActionScript for Flash MX: The Definitive Guide, Second Edition

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Chapter 17

CHAPTER 17

Building a Flash Form

Like HTML, Flash supports fill-in forms that can transfer user input to a server-side

application or script. In this chapter, we’ll see how to capture user input and use the

Flash MX LoadVars class to communicate with a server-side Perl script. You can use

these techniques to save high scores for a video game or retrieve stock ticker data

from a server.

The Flash Form Data Cycle

Before we delve into the particulars, let’s take a macroscopic look at the typical steps

in a form submission process:

1. Flash receives data as user input.

2. Flash prepares data for submission to the web server (collects and validates vari-

ables).

3. Flash sends data to the web server via HTTP (or, optionally, HTTPS).

4. The web server receives data and passes it to a server-side data-handling applica-

tion (e.g., Perl script, PHP script, Cold Fusion, or ASP).

5. The data-handling application parses and processes the submitted data.

6. The data-handling application passes the results to the web server, which sends

the results to Flash.

7. Flash stores and, optionally, displays the results.

Therefore, a functioning Flash form requires:

• A front end (what the user sees)

• Some Flash scripting that submits the form’s contents to a server-side script or

application

• A server-side ...