handler.go

func (api ProductsAPI) Create() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var product models.Product

		if r.Method != http.MethodPost {
			code := http.StatusMethodNotAllowed
			httpError := common.NewError(common.HTTPFriendlyStatus(code), code)
			common.SendErrorResult(w, httpError)
			return
		}

		if err := json.NewDecoder(r.Body).Decode(&product); err != nil {
			code := http.StatusBadRequest
			httpError := common.NewError(common.HTTPFriendlyStatus(code), code)
			common.SendErrorResult(w, httpError)
			return
		}

		data := fmt.Sprintf("%s: Created!\n", api.Text)
		common.SendSuccessResult(w, data)
	}
}

response.go

.....

//SendErrorResult ...
func SendErrorResult(res http.ResponseWriter, err error) {
	res.Header().Set("content-type", "application/json")
	encoder := json.NewEncoder(res)
	encoder.SetEscapeHTML(false)
	obj, ok := err.(interface{ Status() int })
	if ok == true {
		res.WriteHeader(obj.Status())
	}
	m := func(r string) string {
		if r == "" {
			return r
		}
		return strings.ToUpper(string(r[0])) + string(r[1:])
	}(err.Error())
	encoder.Encode(APIErrorMessage{"error", m})
}