Consuming your Golang APIs
We’re going to build on our previous frontend example to add some functions to GET and POST from a simple backend service. The source code can be found inside the chapter9/backend folder; it focuses on two simplified functions that do little more than return a fixed string for GET and a reversed string based on the POST request that we sent.
The appGET() function provides the functionality to perform a GET operation, while the appPOST() function provides it for a POST operation:
func appGET() http.HandlerFunc {
    type ResponseBody struct {
        Message string
    }
    return func(rw http.ResponseWriter, req *http.Request) {
        log.Println("GET", req)
        json.NewEncoder(rw).Encode(ResponseBody{
        ...
