Applications built with the Flex framework are commonly both dynamic and data-centric: They use, present, and allow users to modify data that's imported at runtime from a server-based data store (or, in the case of desktop applications running on AIR, a local database).
Flash Player and the Adobe Integrated Runtime don't have the ability to communicate directly with server-based data storage applications such as database and LDAP servers. Instead, they're designed to communicate with middleware application servers using a variety of protocols.
The Flex framework includes three Remote Procedure Call (RPC) components that allow you to integrate your Flex applications with common application server products. Of these, the
HTTPService component has the most flexibility in terms of the format of messages that are exchanged between the client and server at runtime. Unlike the other RPC components, you can use the HTTP Service component with any application server, because it exchanges data in the form of simple HTTP parameters and XML of any flavor.
In this chapter, I describe the use of the
HTTPService component to retrieve data from a Web server at runtime. I also cover how to send data from a Flex application to a dynamic application server using HTTP requests that are similar to those that are sent from a Web browser using a hyperlink or a data entry form.
To use the sample code for this chapter, import the chapter21.
zip Flex project archive ...