Separation of logic from request handlers

gistfile1.js

// mylogic.js
var MyLogic = {
	_currentAccount: null,
	
	fetchAccountByID: function(id) {
		// fetch account from database, use promises to reject/resolve
	},
	setCurrentAccount: function(account) {
		MyLogic._currentAccount = account;
	}
	getCurrentAccount: function(account) {
		return MyLogic._currentAccount;
	}
	viewAccount: function(account)
		account = account || MyLogic.getCurrentAccount();
		return Promise.resolve()
			.then(function() {
				if (!account) {
					throw new Error('No account found');
				}
				return {
					account: account,
					users: ['test user 1']
				};
			});
	}
};

module.exports = MyLogic;

// MyController.js

var myLogic = require('./mylogic');

module.exports = {
	paramID: function(req, res, next) {
		mylogic.fetchAccountById(req.param.accountID)
			.then(function(account) {
				myLogic.setCurrentAccount(account);
				next();
			})
			.catch(function(err) {
				next(err);
			}).done();
	},
	view: function(req, res, next) {
		myLogic.viewAccount(myLogic.getCurentAccount())
			.then(viewmodel) {
				res.render('account', viewmodel);
			})
			.catch(function(err) {
				res.render('account/error', {
					error: err.message
				});
			}).done();
	}
}

// routes.js

app.param('accountID', mycontroller.paramID);
app.get('/accounts/:accountID', mycontroller.view);