TodoApps

todo.go

package main

import (
	"github.com/gorilla/mux"
	"net/http"
	"github.com/codegangsta/negroni"
	"encoding/json"
	"strconv"
	"time"
	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

type Todo struct  {
	Id int `json:"id"`
	Name string `json:"name"`
	Completed bool `json:"completed"`
}

type MyHandler struct {
	MongoSession *mgo.Session
}

func (h *MyHandler) CompleteTodo(res http.ResponseWriter, req *http.Request)  {
	req.ParseForm()
	id, err := strconv.Atoi(req.FormValue("id"))

	if err != nil {
		panic(err)
	}

	complete, err := strconv.ParseBool(req.FormValue("complete"))

	if err != nil {
		panic(err)
	}

	c := h.MongoSession.DB("project").C("todo")
	todo := &Todo{}
	err = c.Find(bson.M{"id": id}).One(todo)

	if err != nil {
		j, _ := json.Marshal(bson.M{"error": 404, "message": "not found"})
		res.Write(j)
		return
	}

	todo.Completed = complete
	c.Update(bson.M{"id": id}, todo)

	j, _ := json.Marshal(todo)
	res.Write(j)
}

func (h *MyHandler) DeleteTodo(res http.ResponseWriter, req *http.Request)  {
	id, err := strconv.Atoi(req.URL.Query().Get("id"))

	if err != nil {
		panic(err)
	}

	c := h.MongoSession.DB("project").C("todo")

	todo := &Todo{}
	err = c.Find(bson.M{"id" : id}).One(todo)

	if err != nil {
		j, _ := json.Marshal(bson.M{"error": 404, "message": "not found"})
		res.Write(j)
		return
	}

	c.Remove(bson.M{"id": id})

	j, err := json.Marshal(todo)
	res.Write(j)
}

func (h *MyHandler) AddTodo(res http.ResponseWriter, req *http.Request)  {
	req.ParseForm()

	// generate ID based on timestamp
	id := time.Now().Nanosecond()

	todo := &Todo{Id: id, Name: req.FormValue("name"), Completed: false}
	json, err := json.Marshal(todo)

	if err != nil {
		panic(err)
	}

	c := h.MongoSession.DB("project").C("todo")
	err = c.Insert(todo)

	if err != nil {
		panic(err)
	}

	res.Write(json)
}

func main() {
	session, err := mgo.Dial("localhost")
	
	if err != nil {
		panic(err)
	}

	ctx := &MyHandler{MongoSession: session}

	defer session.Close()

	r := mux.NewRouter()
	r.HandleFunc("/todo", ctx.AddTodo).Methods("POST")
	r.HandleFunc("/todo", ctx.DeleteTodo).Methods("DELETE")
	r.HandleFunc("/todo", ctx.CompleteTodo).Methods("PUT")
	n := negroni.Classic()

	n.Use(negroni.HandlerFunc(func(res http.ResponseWriter, req *http.Request, next http.HandlerFunc) {
		res.Header().Add("Content-Type", "application/json")
		next(res, req)
	}))

	n.UseHandler(r)
	n.Run(":8000")
}