MVC

GitBook allows you to organize your book into chapters, each chapter is stored in a separate file like this one.

Apa itu MVC Design Pattern

Mengapa MVC

pada bab 3 kita akan membuat struktur aplikasi sesuai konsep MVC

• copy folder 02-config dan paste dengan nama 03-mvc

• pastikan semua import yang mengarah ke 02-config diubah ke 03-mvc

• buat folder controllers, models, repositories, dan libraries

• pindahkan semua func struct dan var ke file controllers/userController.go, sehingga fi file main.go hanya ada func main() beserta import yang dibutuhkan.

• jangan lupa tambahkan import 03-mvc/controllers di file main.go

sehingga isi dari file main.go jadi seperti ini:

package main

import (
    "github.com/gorilla/mux"
    "net/http"
    "github.com/jacky-htg/api-go/02-config-file/config"
    "github.com/jacky-htg/api-go/03-mvc/controllers"
)

func main() {
    router := mux.NewRouter()

    router.HandleFunc("/api/users", controllers.GetUsersEndPoint).Methods("GET")
    router.HandleFunc("/api/users", controllers.CreateUserEndPoint).Methods("POST")
    router.HandleFunc("/api/users/{id}", controllers.GetUserEndPoint).Methods("GET")

    http.ListenAndServe(config.GetString("server.address"), router)
}

dari file controllers/userController.go pindahkan type User ke file models/user.go

package models

import "time"

type User struct {
    ID            int64
    Name        string
    Email       string
    CreatedAt   time.Time
    UpdateAt    time.Time
    DeletedAt   time.Time
}

import models, dan ubah semua baris User menjadi models.user
pindahkan semua operasi data ke file repositories/userRepository.go

package repositories

import (
    "time"
    "github.com/jacky-htg/api-go/03-mvc/models"
)

var users []models.User

func GetUsers()([]models.User) {
    return users
}

func CreateUser(user models.User)(models.User) {
    user.ID         = int64(len(users)+1)
    user.CreatedAt  = time.Now()

    users = append(users, user)
    return user
}

func GetUser(id int64)(models.User) {
    for _, v := range users {
        if v.ID == id {
            return v
        }
    }

    return models.User{}
}

panggil fungsi2 di userRepository.go di controllers/userCOntroller.go

package controllers

import (
    "encoding/json"
    "net/http"
    "strconv"
    "github.com/gorilla/mux"
    "github.com/jacky-htg/api-go/03-mvc/models"
    "github.com/jacky-htg/api-go/03-mvc/repositories"
)

func GetUsersEndPoint(w http.ResponseWriter, _ *http.Request) {
    json.NewEncoder(w).Encode(repositories.GetUsers())
}

func CreateUserEndPoint(w http.ResponseWriter, req *http.Request) {
    var user models.User

    user.Name   = req.FormValue("name")
    user.Email  = req.FormValue("email")

    // Validation
    if len(user.Name) == 0 {
        json.NewEncoder(w).Encode("Please suplay valid name")
        return
    }

    if len(user.Email) == 0 {
        json.NewEncoder(w).Encode("Please suplay valid email")
        return
    }

    json.NewEncoder(w).Encode(repositories.CreateUser(user))
}

func GetUserEndPoint(w http.ResponseWriter, req *http.Request) {
    params := mux.Vars(req)
    id, _  := strconv.ParseInt(params["id"], 10, 64)

    json.NewEncoder(w).Encode(repositories.GetUser(id))
}

terakhir kita kan memindahkan handling error ke dalam file libraries/generic.go

buat file libraries/generic.go yang berisi :

package libraries

import "fmt"

func CheckError(err error){
    if err != nil {
        fmt.Println(err.Error())
        panic(err.Error())
    }
}

buka file config/config.go dan ubah handling error dg memanggil fungsi CheckError()

package config

import (
    "github.com/spf13/viper"
    "github.com/jacky-htg/api-go/03-mvc/libraries"
)

func init() {
    viper.SetConfigFile("./config/config.json")
    err := viper.ReadInConfig()
    libraries.CheckError(err)
}

func GetString(key string)(string) {
    return viper.GetString(key)
}

func GetInt(key string)(int) {
    return viper.GetInt(key)
}