When the service program signals that a response is available, the request handler replaces the XMLExchange tag with the entire contents response contained in the exchange file. During this process, the request handler also examines the contents of the exchange file for certain request handler tags, and processes those tags before sending the response back to the web client. These tags are useful in controlling information such as the MIME type of the response and other information that may only be determined by the service program. Likewise, the service program may wish to send information in the response that is known only by the request handler; replacement tags are used for this purpose.
When the request handler encounters the end of the SRF file, the response that has been accumulated is sent back to the web client.