Locals in ExpressJS

Using Local Variables in Express

ExpressJS allows you to define "locals" which are variables available to the view in multiple places and in multiple ways. Here are a few examples.

	// using the res.local syntax
	app.all('*', function(req, res, next) {
	db.logs.findOne(function(err, logs) {
	if (err) return console.log("Error: ", err);
	res.local('count', logs.count);
	res.local('edit', false);
	next();
	});
	});
	// alternatively the res.locals syntax
	app.all('*', function(req, res, next) {
	db.logs.findOne(function(err, logs) {
	if (err) return console.log("Error: ", err);
	res.locals({
	'count': logs.count,
	'edit': false
	});
	next();
	});
	});
	// finally, as the second argument to a render call
	app.get('/reviews/add', function(req, res) {
	res.render('view.html', {
	review: {
	rating: 0,
	title: "This is the place.",
	article: "This is your review.",
	images: [],
	slug: "your-url"
	}
	});
	});
	// in the first two cases you can confirm which variables
	// have been set simply by inspect the _locals variable
	console.log("Locals: ", res._locals);

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