Programming Flex 2

Chapter 16. Remote Data Communication

Remote data communication occurs at runtime. It does not reside strictly in the client, but requires network connections to send and receive data between the client and the server. Flex applications support a variety of remote data communication techniques built on standards. There are three basic categories of Flex application remote data communication:

HTTP request/response-style communication

This category consists of several overlapping techniques. Utilizing the Flex framework HTTPService component or the Flash Player API URLLoader class, you can send and load uncompressed data such as text blocks, URL encoded data, and XML packets. You can also send and receive SOAP packets using the Flex framework WebService component. And you can use a technology called Flash Remoting to send and receive AMF packets, which use a binary protocol that is similar to SOAP (but considerably smaller). Each technique achieves the similar goal of sending requests and receiving responses using HTTP or HTTPS.

Real-time communication

This category consists of persistent socket connections. Flash Player supports two types of socket connections: those that require a specific format for packets (XMLSocket) and those that allow raw socket connections (Socket). In both cases, the socket connection is persistent between the client and the server, allowing the server to push data to the client--something not possible using standard HTTP request/response-style techniques.