On the server, request handlers are invoked on incoming requests immediately after all of the transport handlers have been invoked; on the client, they are invoked immediately before the transport handlers are invoked. See Figure 8.

On the server, the first request handler to get invoked is always the SOAP message handler generated by HydraExpress. This handler parses the SOAP message and makes parts of the message available through methods of the rwsf::CallInfo object associated with the request. You can create additional handlers, as described later in this chapter.