lets-go:11.6 authz again

snippetbox/cmd/web/helpers.go

@@ -17,8 +17,8 @@ func (app *application )newTemplateData(r *http.Request) templateData {
 	return templateData{
 		CurrentYear:     time.Now().Year(),
 		Flash:           app.sessionManager.PopString(r.Context(), "flash"),
+		IsAuthenticated: app.isAuthenticated(r),
 	}
-
 }
 
 // render ...
@@ -81,3 +81,7 @@ func (app *application) decodePostForm(r *http.Request, dst any) error {
 
 	return nil
 }
+
+func (app *application) isAuthenticated(r *http.Request) bool {
+	return app.sessionManager.Exists(r.Context(), "authenticatedUserID")
+}

snippetbox/cmd/web/middleware.go

@@ -46,3 +46,16 @@ func secureHeaders(next http.Handler) http.Handler {
 		next.ServeHTTP(w, r)
 	})
 }
+
+func (app *application) requireAuthentication(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !app.isAuthenticated(r) {
+			http.Redirect(w, r, "/user/login", http.StatusSeeOther)
+			return
+		}
+
+		w.Header().Add("Cache-Control", "no-store")
+
+		next.ServeHTTP(w, r)
+	})
+}

snippetbox/cmd/web/routes.go

@@ -27,13 +27,16 @@ func (app *application) routes() http.Handler {
 
 	router.Handler(http.MethodGet, "/", dynamic.ThenFunc(app.home))
 	router.Handler(http.MethodGet, "/snippet/view/:id", dynamic.ThenFunc(app.snippetView))
-	router.Handler(http.MethodGet, "/snippet/create", dynamic.ThenFunc(app.snippetCreate))
-	router.Handler(http.MethodPost, "/snippet/create", dynamic.ThenFunc(app.snippetCreatePost))
 	router.Handler(http.MethodGet, "/user/signup", dynamic.ThenFunc(app.userSignup))
 	router.Handler(http.MethodPost, "/user/signup", dynamic.ThenFunc(app.userSignupPost))
 	router.Handler(http.MethodGet, "/user/login", dynamic.ThenFunc(app.userLogin))
 	router.Handler(http.MethodPost, "/user/login", dynamic.ThenFunc(app.userLoginPost))
-	router.Handler(http.MethodPost, "/user/logout", dynamic.ThenFunc(app.userLogoutPost))
+
+	protected := dynamic.Append(app.requireAuthentication)
+
+	router.Handler(http.MethodGet, "/snippet/create", protected.ThenFunc(app.snippetCreate))
+	router.Handler(http.MethodPost, "/snippet/create", protected.ThenFunc(app.snippetCreatePost))
+	router.Handler(http.MethodPost, "/user/logout", protected.ThenFunc(app.userLogoutPost))
 
 	standard := alice.New(app.recoverPanic, app.logRequest, secureHeaders)
 

snippetbox/cmd/web/templates.go

@@ -14,6 +14,7 @@ type templateData struct {
 	Snippets        []models.Snippet
 	Form            any
 	Flash           string
+	IsAuthenticated bool
 }
 
 // humanDate ...

snippetbox/ui/html/partials/nav.tmpl

@@ -2,14 +2,19 @@
     <nav>
       <div>
         <a href="/">Home</a>
+        {{if .IsAuthenticated}}
         <a href="/snippet/create">Create Snippet</a>
+        {{end}}
       </div>
       <div>
-        <a href="/user/signup">Signup</a>
-        <a href="/user/login">Login</a>
+        {{if .IsAuthenticated}}
         <form action="/user/logout" method="POST">
           <button>Logout</button>
         </form>
+        {{else}}
+        <a href="/user/signup">Signup</a>
+        <a href="/user/login">Login</a>
+        {{end}}
       </div>
     </nav>
 {{end}}