userRouter.go

// all Go executables need a main package
package main

// importing packages
// log : loggin status and errors
// net/http : http package for REST API
import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/gorilla/mux"
)

func params(w http.ResponseWriter, r *http.Request) {
	pathParams := mux.Vars(r)
	w.Header().Set("Content-Type", "application/json")

	userID := 0
	var err error
	if val, ok := pathParams["userID"]; ok {
		userID, err = strconv.Atoi(val)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte(`{"message": "need a number"}`))
			return
		}
	}

	commentID := -1
	if val, ok := pathParams["commentID"]; ok {
		commentID, err = strconv.Atoi(val)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte(`{"message": "need a number"}`))
			return
		}
	}

	query := r.URL.Query()
	location := query.Get("location")

	w.Write([]byte(fmt.Sprintf(`{"userID": %d, "commentID": %d, "location": "%s" }`, userID, commentID, location)))
}