Node: how to implement isLoggedIn before all routes?
I want to write a helper function isLoggedIn that is used to judge if any user is logged in, if you are logged in set res.locals.is_logged_in = true.
var isLoggedIn = function(req, res, next) {
User.findById(sessions.user_id, function(err, user) {
if (err) throw err;
return !user ? false : true;
});
};
then before all routes I write
.use(express.static(path.join(__dirname, '/public')))
.use(express.static(path.join(__dirname, '/bower_components')))
.use(flash)
.use(function(req, res, next) {
if (isLoggedIn(req, res, next)) {
res.locals.is_logged_in = true;
res.locals.current_user = '/users/' + req.user._id;
} else {
res.locals.is_logged_in = false;
}
res.locals.showTests = app.get('env') !== 'production' &&
req.query.test === '1';
next();
});
var routes = require('./routes/routes.js');
app.use('/', routes.staticPages());
app.use('/', routes.sessions(sessionHelper));
app.use('/users', routes.users(sessionHelper));
But I figured out that findById is an asynchronous function, so I can't get the correct behavior this way.
I tried
var isLoggedIn = function(callback) {
User.findById(sessions.user_id, function(err, user) {
if (err) throw err;
callback(user);
});
};
.use(function(req, res, next) {
sessionHelper.isLoggedIn(function(user) {
if (!user) {
console.log("no");
res.locals.is_logged_in = false;
} else {
console.log("yes");
res.locals.is_logged_in = true;
res.locals.current_user = '/users/' + req.user._id;
}
});
res.locals.showTests = app.get('env') !== 'production' &&
req.query.test === '1';
next();
});
This doesn't work either: in some routes I print res.locals.is_logged_in , I get the value "undefined" . How can I solve this problem?
+3
source to share
1 answer
You need an asynchronous call. In your case, you have to use a callback:
.use(function(req, res, next) {
sessionHelper.isLoggedIn(function(user) {
if (!user) {
console.log("no");
res.locals.is_logged_in = false;
} else {
console.log("yes");
res.locals.is_logged_in = true;
res.locals.current_user = '/users/' + req.user._id;
}
next(); // next MUST be here in order to continue AFTER db query
});
res.locals.showTests = app.get('env') !== 'production' &&
req.query.test === '1';
//next(); // remove this from here, as it makes it continue without waiting for db query
});
+1
source to share