User Authentication on MEAN stack application - node.js

Question

I am building an API using the MEAN stack and am working on the login and signup functions.
And I want to respond with a json string as follows
{
success: 0,
message: ""
}
success:1 for successful login and 0 otherwise.
My authenticate.js is as follows
module.exports = function(passport){
//log in
router.post('/login', passport.authenticate('login', {
//success
//failure
}));
//sign up
router.post('/signup', passport.authenticate('signup', {
//success
//failure
}));
//log out
router.get('/signout', function(req, res) {
req.logout();
res.redirect('/');
});
return router;
}
My passport.init.js middleware is as follows
var mongoose = require('mongoose');
var User = mongoose.model('User');
var LocalStrategy = require('passport-local').Strategy;
var bCrypt = require('bcrypt-nodejs');
module.exports = function(passport){
// Passport needs to be able to serialize and deserialize users to support persistent login sessions
passport.serializeUser(function(user, done) {
console.log('serializing user:',user.username);
done(null, user._id);
});
passport.deserializeUser(function(id, done) {
User.findById(id, function(err, user) {
console.log('deserializing user:',user.username);
done(err, user);
});
});
passport.use('login', new LocalStrategy({
passReqToCallback : true
},
function(req, username, password, done) {
// check in mongo if a user with username exists or not
User.findOne({ 'username' : username },
function(err, user) {
// In case of any error, return using the done method
if (err)
return done(err);
// Username does not exist, log the error and redirect back
if (!user){
console.log('User Not Found with username '+username);
return done(null, false);
}
// User exists but wrong password, log the error
if (!isValidPassword(user, password)){
console.log('Invalid Password');
return done(null, false); // redirect back to login page
}
// User and password both match, return user from done method
// which will be treated like success
return done(null, user);
}
);
}
));
passport.use('signup', new LocalStrategy({
passReqToCallback : true // allows us to pass back the entire request to the callback
},
function(req, username, password, done) {
// find a user in mongo with provided username
User.findOne({ 'username' : username }, function(err, user) {
// In case of any error, return using the done method
if (err){
console.log('Error in SignUp: '+err);
return done(err);
}
// already exists
if (user) {
console.log('User already exists with username: '+username);
return done(null, false);
} else {
// if there is no user, create the user
var newUser = new User();
// set the user's local credentials
newUser.username = username;
newUser.password = createHash(password);
// save the user
newUser.save(function(err) {
if (err){
console.log('Error in Saving user: '+err);
throw err;
}
console.log(newUser.username + ' Registration succesful');
return done(null, newUser);
});
}
});
})
);
var isValidPassword = function(user, password){
return bCrypt.compareSync(password, user.password);
};
// Generates hash using bCrypt
var createHash = function(password){
return bCrypt.hashSync(password, bCrypt.genSaltSync(10), null);
};
};
Please help me out in passing the JSON string accordingly

Answer 1

Using Express, all you have to do is to execute res.json inside any controller, passing it any JavaScript object. Express will automatically convert it to JSON and return it to the user.
return res.json({ success: 0, message: '' }