When you start to integrate data into a Flex application, you have to solve the problem of how to get data into the Flex runtime environment. As shown in earlier chapters, data can be embedded into the application using hard-coded MXML or ActionScript, or by integrating data into the application with the
<mx:Model> tag. These strategies, however, only work for data that's both small and static.
For existing data that's retrieved from a server-based resource, such as a database or an XML file, you can use Remote Procedure Call (RPC) components such as HTTPService (Chapter 21), WebService (Chapter 23), and RemoteObject (Chapters 24, 27, and 28).
And then there's data that comes from the user. Unless an application is used exclusively with static data or content retrieved from a server at runtime, a data-centric application must collect data from the user. In this chapter, I describe the use of the following tools for building data entry form components:
The Form, FormHeading, and FormItem components for laying out a data entry form
Validator components to validate a user's data entry
Custom value object and event classes to share data with the rest of the application
This chapter also includes tutorials that allow you to integrate many of the techniques described in preceding chapters, including the use of containers and controls (Chapter 8 and Chapter 9), creating custom MXML components (Chapter 5), modeling data with custom ActionScript classes ...