Listener Pattern
The extension API leverages a listener pattern to deliver callbacks to extension points to allow injecting custom logic.
A call made to the traffic manager is an invocation to a series of tasks. Each step in the workflow accomplishes a specific task to fulfill the call. The current API release only allows customization of the tasks prior to invoking the API server (pre-process) and post receipt of the response from the API server (post-process). The callback API handling these extensions is called a Processor.
The pre-process step allows a processor to receive a fully-formed HTTP request targeted to the API server. The processor is allowed to alter the headers or the body of the request prior to the request being made to the server. Upon completion of the request and receiving the response the Traffic Manager allows the processor to alter the response content and headers prior to the response flowing back through a series of exit tasks out to the client.