chore: add error messages to login form of example (#284)

Author: kheftel

examples/login/app.js

@@ -9,6 +9,7 @@ const bodyParser = require('body-parser');
 const mongoose = require('mongoose');
 const passport = require('passport');
 const LocalStrategy = require('passport-local').Strategy;
+const flash = require('connect-flash');
 
 const app = express();
 
@@ -23,6 +24,7 @@ app.use(bodyParser.json());
 app.use(bodyParser.urlencoded({extended: false}));
 app.use(cookieParser());
 app.use(session({keys: ['secretkey1', 'secretkey2', '...']}));
+app.use(flash());
 
 app.use(express.static(path.join(__dirname, 'public')));
 

examples/login/package-lock.json

@@ -7,6 +7,7 @@
   },
   "dependencies": {
     "body-parser": "^1.19.0",
+    "connect-flash": "^0.1.1",
     "cookie-parser": "^1.4.4",
     "cookie-session": "^1.1.0",
     "debug": "^4.1.1",

examples/login/package.json

@@ -25,12 +25,12 @@ router.post('/register', function(req, res, next) {
 });
 
 router.get('/login', function(req, res) {
-  res.render('login', {user: req.user});
+  res.render('login', {user: req.user, message: req.flash('error')});
 });
 
-router.post('/login', passport.authenticate('local'), function(req, res) {
-  res.redirect('/');
-});
+router.post('/login', passport.authenticate('local', { failureRedirect: '/login', failureFlash: true }), function(req, res) {
+    res.redirect('/');
+  });
 
 router.get('/logout', function(req, res) {
   req.logout();

examples/login/routes.js

@@ -3,6 +3,8 @@ extends layout
 block content
   h2 Log In
 
+  if message != ''
+    .alert.alert-error #{message}
   form(action="/login",method="post")
     div
       label Username