REST API モックサーバー

以下の動画を参考に作成してみた。

Golang REST API With Mux

package main 

import (
	"encoding/json"
	"log"
	"net/http"
	"math/rand"
	"strconv"
	"github.com/gorilla/mux"
)

// Book Struct (Model)
type Book struct {
	ID		string	`json:"id"`
	Isbn	string	`json:"isbn"`
	Title	string	`json:"title"`
	Author	*Author	`json:"author"`
}

// Author Struct
type Author struct {
	Firstname	string `json:"firstname`
	Lastname	string `json:"lastname`
}

// Init books ar as slice Book struct
var books []Book

func main() {
	// Init Router
	r := mux.NewRouter()

	// Mock Data - @todo implement DB
	books = append(books, Book{ID: "1", Isbn:"448753", Title: "Book One", Author: &Author{Firstname: "John", Lastname:"Doe"}})
	books = append(books, Book{ID: "2", Isbn:"846946", Title: "Book Two", Author: &Author{Firstname: "Steve", Lastname:"Smith"}})

	// Route Hundlers/ Endpoints
	r.HandleFunc("/api/books", getBooks).Methods("GET")
	r.HandleFunc("/api/books/{id}", getBook).Methods("GET")
	r.HandleFunc("/api/books", createBook).Methods("POST")
	r.HandleFunc("/api/books/{id}", updateBook).Methods("PUT")
	r.HandleFunc("/api/books/{id}", deleteBook).Methods("DELETE")

	log.Fatal(http.ListenAndServe(":8080", r))

}

// Get All Books
func getBooks(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/json")
	json.NewEncoder(w).Encode(books)
}

// Get Single Book
func getBook(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/json")
	params := mux.Vars(r) //Get params
	// Loop through books and find with id
	for _, item := range books {
		if item.ID == params["id"] {
			json.NewEncoder(w).Encode(item)
			return
		}
	}
	json.NewEncoder(w).Encode(&Book{})
}

// Create a New Book
func createBook(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/json")
	var book Book 
	_ = json.NewDecoder(r.Body).Decode(&book)
	book.ID = strconv.Itoa(rand.Intn(10000000))	// Mock ID - not safe
	books = append(books, book)
	json.NewEncoder(w).Encode(book)
}

// Update Book
func updateBook(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/json")
	params := mux.Vars(r)
	for index, item := range books {
		if item.ID == params["id"] {
			books = append(books[:index], books[index+1:]...)
			var book Book 
			_ = json.NewDecoder(r.Body).Decode(&book)
			book.ID = params["id"]
			books = append(books, book)
			json.NewEncoder(w).Encode(book)
			return
		}
	}
	json.NewEncoder(w).Encode(books)
}

// Delete Book
func deleteBook(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/json")
	params := mux.Vars(r)
	for index, item := range books {
		if item.ID == params["id"] {
			books = append(books[:index], books[index+1:]...)
			break
		}
	}
	json.NewEncoder(w).Encode(books)
}