Actionscript Cookbook

Chapter 16. Storing Persistent Information

Introduction

You already know how to work with data that is stored in memory as long as a Flash movie is open. In fact, almost all data you work with in ActionScript is of this type. But what if you want to be able to store data between Flash movie sessions? Or what if you want to be able to share data between Flash movies running on the same client, or even on different clients? To accomplish these feats, we’ll need to look at how we can store and transmit data outside of the Flash Player.

This chapter addresses both client-side and server-side data. First, we’ll examine client-side data. Prior to Flash 6, the only way to store persistent data on the client was with complex techniques that invoked external JavaScript functions to read and write cookies. However, Flash 6 introduced local shared objects to ActionScript, making it possible to store and retrieve persistent data on the client without the use of these other, complicated techniques.

We’ll also take a closer look at server-side data. Prior to Flash 6, server-side data manipulation was limited to invoking server-side scripts (using loadVariables( ) or an XML object) to read and write data to text files and/or databases on the server. The problem was, of course, that this functionality required that you had the necessary scripts on the server. While this kind of functionality still has its place (although the LoadVars class supercedes the older loadVariables( ) method), this chapter ...