So I am new to go and I currently try to build a little REST-API using chi (and I love it). Yesterday I run into a problem, that I cannot quite understand.
In my little test-project I have a main.go file which contains the main function with router instantiation, adding middlewares and starting the server:
func main() {
router := chi.NewRouter()
// Middleware
router.Use(middleware.RequestID)
router.Use(middleware.RealIP)
router.Use(middleware.Logger)
router.Use(middleware.Recoverer)
// Routes
router.Post("/login", users.Login)
router.Post("/register", users.Register)
router.With(users.LoginRequired).Route("/users", func(r chi.Router) {
r.Get("/{user_id}", users.GetUser)
})
// Start Server
port := ":8080"
log.Printf("Server starting at port %v\n", port)
log.Fatal(http.ListenAndServe(port, router))
}
First the problem didn't exist because I defined all the handler functions within my main.go file and the GetUser-function worked as expected and returned a user from my "Database" (array with 3 users):
func GetUser(w http.ResponseWriter, r *http.Request) {
uID := chi.URLParam(r, "user_id") // Problem when not in main -> uID = ""
id, err := strconv.Atoi(uID)
if err != nil {
log.Printf("Error while parsing int: %v\n", err)
// TODO: return error 400
}
user := DataBase[id-1]
response, err := json.Marshal(user)
if err != nil {
log.Printf("Error while marshalling user: %v\n", err)
}
w.Write(response)
}
As soon as I moved this function out of the main.go file into another package called users the chi.URLParam function returns an empty string and cannot find the URLParam anymore. I read it has something to do with the context, but I cannot wrap my head around that I have to place functions inside the main-file if I want to use the chi functions.
Am I missing something?
UPDATE
As requested I removed everything except the GetUser function. My main.go file currently looks like this:
package main
import (
"encoding/json"
"log"
"net/http"
"strconv"
"github.com/MyUserName/MyProjectName/internals/users"
"github.com/go-chi/chi/v5"
)
func GetUser(w http.ResponseWriter, r *http.Request) {
id, err := strconv.Atoi(chi.URLParam(r, "user_id"))
if err != nil {
log.Printf("Error while parsing int: %v\n", err)
// TODO: return error 400
}
log.Printf("ID=%v, Current Database=%v\n", id, users.DataBase)
user := users.DataBase[id-1]
response, err := json.Marshal(user)
if err != nil {
log.Printf("Error while marshalling user: %v\n", err)
}
w.Write(response)
}
func main() {
router := chi.NewRouter()
// Routes
router.Get("/users/{user_id}", GetUser)
// Start Server
port := ":8080"
log.Printf("Server starting at port %v\n", port)
log.Fatal(http.ListenAndServe(port, router))
}
and my users package looks like this:
package users
import (
"encoding/json"
"log"
"net/http"
"strconv"
"github.com/MyUserName/MyProjectName/internals/models"
"github.com/go-chi/chi"
)
var (
DataBase = make([]models.User, 0)
)
func GetUser(w http.ResponseWriter, r *http.Request) {
id, err := strconv.Atoi(chi.URLParam(r, "user_id"))
if err != nil {
log.Printf("Error while parsing int: %v\n", err)
// TODO: return error 400
}
log.Printf("ID=%v, Current Database=%v\n", id, DataBase)
user := DataBase[id-1]
response, err := json.Marshal(user)
if err != nil {
log.Printf("Error while marshalling user: %v\n", err)
}
w.Write(response)
}
func init() {
initUser := []models.User{
{
ID: 1,
UserName: "john",
Password: "doe",
},
{
ID: 2,
UserName: "max",
Password: "mustermann",
},
{
ID: 3,
UserName: "jane",
Password: "doe",
},
}
for _, user := range initUser {
DataBase = append(DataBase, user)
}
log.Println("Initializing Database")
}
When I use the function from the users package it does not work and is still an empty string, if I use the function from the main.go file it works.
UPDATE
So apparently I am to stupid to import the same packages twice. In my main file I used "github.com/go-chi/chi/v5" and in my users package I used "github.com/go-chi/chi". Using the same resolved the issue, thanks a lot
