add users to the handlers

context.go

@@ -3,12 +3,14 @@ package main
 import (
 	"code.google.com/p/gorilla/sessions"
 	"labix.org/v2/mgo"
+	"labix.org/v2/mgo/bson"
 	"net/http"
 )
 
 type Context struct {
 	Database *mgo.Database
 	Session  *sessions.Session
+	User     *User
 }
 
 func (c *Context) Close() {
@@ -22,8 +24,18 @@ func (c *Context) C(name string) *mgo.Collection {
 
 func NewContext(req *http.Request) (*Context, error) {
 	sess, err := store.Get(req, "gostbook")
-	return &Context{
+	ctx := &Context{
 		Database: session.Clone().DB(database),
 		Session:  sess,
-	}, err
+	}
+	if err != nil {
+		return ctx, err
+	}
+
+	//try to fill in the user from the session
+	if uid, ok := sess.Values["user"].(bson.ObjectId); ok {
+		err = ctx.C("users").Find(bson.M{"_id": uid}).One(&ctx.User)
+	}
+
+	return ctx, err
 }

handlers.go

@@ -1,6 +1,9 @@
 package main
 
-import "net/http"
+import (
+	"errors"
+	"net/http"
+)
 
 func hello(w http.ResponseWriter, req *http.Request, ctx *Context) (err error) {
 	//set up the collection and query
@@ -15,17 +18,23 @@ func hello(w http.ResponseWriter, req *http.Request, ctx *Context) (err error) {
 	}
 
 	//execute the template
-	return T("index.html").Execute(w, entries)
+	return T("index.html").Execute(w, map[string]interface{}{
+		"entries": entries,
+		"ctx":     ctx,
+	})
 }
 
 func sign(w http.ResponseWriter, req *http.Request, ctx *Context) (err error) {
+	//we need a user to sign to
+	if ctx.User == nil {
+		err = errors.New("Can't sign without being logged in")
+		return
+	}
+
 	entry := NewEntry()
-	entry.Name = req.FormValue("name")
+	entry.Name = ctx.User.Username
 	entry.Message = req.FormValue("message")
 
-	if entry.Name == "" {
-		entry.Name = "Some dummy who forgot a name"
-	}
 	if entry.Message == "" {
 		entry.Message = "Some dummy who forgot a message."
 	}
@@ -40,5 +49,28 @@ func sign(w http.ResponseWriter, req *http.Request, ctx *Context) (err error) {
 }
 
 func loginForm(w http.ResponseWriter, req *http.Request, ctx *Context) (err error) {
-	return T("login.html").Execute(w, nil)
+	return T("login.html").Execute(w, map[string]interface{}{
+		"ctx": ctx,
+	})
+}
+
+func login(w http.ResponseWriter, req *http.Request, ctx *Context) error {
+	username, password := req.FormValue("username"), req.FormValue("password")
+
+	user, e := Login(ctx, username, password)
+	if e != nil {
+		ctx.Session.AddFlash("Invalid Username/Password")
+		return loginForm(w, req, ctx)
+	}
+
+	//store the user id in the values and redirect to index
+	ctx.Session.Values["user"] = user.ID
+	http.Redirect(w, req, reverse("index"), http.StatusSeeOther)
+	return nil
+}
+
+func logout(w http.ResponseWriter, req *http.Request, ctx *Context) error {
+	delete(ctx.Session.Values, "user")
+	http.Redirect(w, req, reverse("index"), http.StatusSeeOther)
+	return nil
 }

http.go

@@ -12,6 +12,7 @@ func (h handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	ctx, err := NewContext(req)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
 	}
 	defer ctx.Close()
 
@@ -20,11 +21,13 @@ func (h handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	err = h(buf, req, ctx)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
 	}
 
 	//save the session
 	if err = ctx.Session.Save(req, buf); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
 	}
 
 	//apply the buffered response to the writer

main.go

@@ -3,8 +3,10 @@ package main
 import (
 	"code.google.com/p/gorilla/pat"
 	"code.google.com/p/gorilla/sessions"
+	"encoding/gob"
 	"fmt"
 	"labix.org/v2/mgo"
+	"labix.org/v2/mgo/bson"
 	"net/http"
 	"os"
 )
@@ -23,6 +25,10 @@ func reverse(name string, things ...interface{}) string {
 	return u.Path
 }
 
+func init() {
+	gob.Register(bson.ObjectId(""))
+}
+
 var store sessions.Store
 var session *mgo.Session
 var database string
@@ -40,6 +46,8 @@ func main() {
 
 	router = pat.New()
 	router.Add("GET", "/login", handler(loginForm)).Name("login")
+	router.Add("GET", "/logout", handler(logout)).Name("logout")
+	router.Add("POST", "/login", handler(login))
 	router.Add("GET", "/", handler(hello)).Name("index")
 	router.Add("POST", "/sign", handler(sign)).Name("sign")
 

templates/index.html

@@ -6,7 +6,7 @@ <h1>Guestbook</h1>
     <p>Hello, and welcome to my guestbook, because it's 1997!</p>
 
     <ul class="guests">
-        {{ range . }}
+        {{ range .entries }}
         <li>
             <blockquote>{{ .Message }}</blockquote>
             <p>- <cite>{{ .Name }}</cite>, <time>{{ .Timestamp }}</time></p>
@@ -15,12 +15,13 @@ <h1>Guestbook</h1>
     </ul>
 
     <hr>
-    <a href="{{ reverse "login" }}">login</a>
-    <hr>
-
+    {{ if .ctx.User }}
     <form action="{{ reverse "sign" }}" method="POST">
-        <p>Name: <input type="text" name="name"></p>
+        <p>Name: {{ .ctx.User.Username }} (<a href="{{ reverse "logout" }}">Logout</a>)</p>
         <p>Message: <textarea name="message" rows="10" cols="40"></textarea></p>
         <p><button>Sign</button></p>
     </form>
+    {{ else }}
+        <h1>Please <a href="{{ reverse "login" }}">login</a> to sign.</h1>
+    {{ end }}
 {{ end }}

templates/login.html

@@ -2,6 +2,11 @@
 
 {{ define "content" }}
     <h1>Login</h1>
+
+    {{ range .ctx.Session.Flashes }}
+        <h2>{{ . }}</h2>
+    {{ end }}
+
     <form action="{{ reverse "login" }}" method="POST">
         <p>Username: <input type="text" name="username"></p>
         <p>Password: <input type="password" name="password"></p>

user.go

@@ -24,7 +24,7 @@ func (u *User) SetPassword(password string) {
 
 //Login validates and returns a user object if they exist in the database.
 func Login(ctx *Context, username, password string) (u *User, err error) {
-	err = ctx.C("users").Find(bson.M{"username": username}).One(u)
+	err = ctx.C("users").Find(bson.M{"username": username}).One(&u)
 	if err != nil {
 		return
 	}