Express: pass variable to main layout - express

Question

I'm starting to learn Express and I'm stuck trying to pass a variable in my default layout, that gets loaded every time I render a view, so I don't have to pass it every time I res.render something, like below:
router.get('/', function(req, res, next) {
res.render('home', { title: 'title1', 'isuser':req.user});
});
router.get('/loggedin',function(req,res){
res.render('loggedin', {title: 'title2', 'isuser':req.user});
});
router.get('/register', isLoggedIn, function(req,res)
{
res.render('register', {title: 'title3', 'isuser':req.user});
});
I don't want to pass isuser every time I render, that's why I want to just pass it to my main layout so the information is used automatically.
The default layout isn't explicitly rendered in code (with res.render) but acts like a frame for all rendered views and gets loaded automatically. In my case I use handlebars and I load the default layout like so, in my main app.js:
app.engine('handlebars', expbhs({defaultLayout:'defaultLayout'}));

Answer 1

In Node, you can simply create endpoints server-side, like this:
app.get('login/', function(request, response){
response.render('loginpage', { any data you need });
});
app.get('logout/', function(request, response){
response.render('logoutpage', { any data you need });
});
loginpage and logoutpage are in your views folder and can be jade, handlebars, or any other template. The data to be filled in can be passed as shown above, possibly extracted from the request.
In your HTML you can simply link to your 'login' page (not '/login'), and this should then return your login page.

Answer 2

I realize this question is a couple years old, but I had the exact same question. I think the OP is using express-handlebars (given the "expbhs" abbreviation), so this documentation should be relevant: https://www.npmjs.com/package/express-handlebars#helpers
When you create your instance of express-handlebars, you can pass it some parameters such as defaultLayout and a list of helper functions to generate the data you want to insert into your template.
In my case, I was trying to display the current year in the main template's footer (which appears on every page). Like OP, I did not want to pass this data into every single route.
var handlebars = require('express-handlebars').create({
defaultLayout:'main',
helpers: {
year: function() {
return new Date().getFullYear();
}
}
});
This results in displaying the year where I've written {{year}} in main.handlebars. Hope this helps someone else.