gorillamux1.go

package main
import (
    "encoding/json"
    "fmt"
    "net/http"
    "github.com/gorilla/mux"
)
type User struct {
    ID        string `json:"id"`
    Lastname  string `json:"lastname"`
    Firstname string `json:"firstname"`
    Age       int    `json:"age"`
    Email     string `json:"email"`
}
var users = []User{}
func main() {
    r := mux.NewRouter()
    usersR := r.PathPrefix("/users").Subrouter()
    usersR.Path("").Methods(http.MethodGet).HandlerFunc(getAllUsers)
    usersR.Path("").Methods(http.MethodPost).HandlerFunc(createUser)
    usersR.Path("/{id}").Methods(http.MethodGet).HandlerFunc(getUserByID)
    usersR.Path("/{id}").Methods(http.MethodPut).HandlerFunc(uptdateUser)
    usersR.Path("/{id}").Methods(http.MethodDelete).HandlerFunc(deleteUser)
    fmt.Println("Start listening")
    fmt.Println(http.ListenAndServe(":8080", r))
}
func getAllUsers(w http.ResponseWriter, r *http.Request) {
    w.Header().Add("Content-Type", "application/json")
    if err := json.NewEncoder(w).Encode(users); err != nil {
        fmt.Println(err)
        w.WriteHeader(http.StatusInternalServerError)
    }
}
func getUserByID(w http.ResponseWriter, r *http.Request) {
    id := mux.Vars(r)["id"]
    index := indexByID(users, id)
    if index < 0 {
        w.WriteHeader(http.StatusNotFound)
        return
    }
    w.Header().Add("Content-Type", "application/json")
    if err := json.NewEncoder(w).Encode(users[index]); err != nil {
        fmt.Println(err)
        w.WriteHeader(http.StatusInternalServerError)
    }
}
func uptdateUser(w http.ResponseWriter, r *http.Request) {
    id := mux.Vars(r)["id"]
    index := indexByID(users, id)
    if index < 0 {
        w.WriteHeader(http.StatusNotFound)
        return
    }
    u := User{}
    if err := json.NewDecoder(r.Body).Decode(&u); err != nil {
        w.WriteHeader(http.StatusBadRequest)
        return
    }
    users[index] = u
    w.Header().Add("Content-Type", "application/json")
    if err := json.NewEncoder(w).Encode(&u); err != nil {
        fmt.Println(err)
        w.WriteHeader(http.StatusInternalServerError)
    }
}
func deleteUser(w http.ResponseWriter, r *http.Request) {
    id := mux.Vars(r)["id"]
    index := indexByID(users, id)
    if index < 0 {
        w.WriteHeader(http.StatusNotFound)
        return
    }
    users = append(users[:index], users[index+1:]...)
    w.WriteHeader(http.StatusOK)
}
func createUser(w http.ResponseWriter, r *http.Request) {
    u := User{}
    if err := json.NewDecoder(r.Body).Decode(&u); err != nil {
        w.WriteHeader(http.StatusBadRequest)
        return
    }
    users = append(users, u)
    response, err := json.Marshal(&u)
    if err != nil {
        fmt.Println(err)
        w.WriteHeader(http.StatusInternalServerError)
        return
    }
    w.Header().Add("Content-Type", "application/json")
    w.WriteHeader(http.StatusCreated)
    w.Write(response)
}
func indexByID(users []User, id string) int {
    for i := 0; i < len(users); i++ {
        if users[i].ID == id {
            return i
        }
    }
    return -1
}