I want to split up my routes into different files, where one file contains all routes and the other one the corresponding actions. I currently have a solution to achieve this, however I need to make the app-instance global to be able to access it in the actions. My current setup looks like this:
app.js:
var express = require('express');
var app = express.createServer();
var routes = require('./routes');
var controllers = require('./controllers');
routes.setup(app, controllers);
app.listen(3000, function() {
console.log('Application is listening on port 3000');
});
routes.js:
exports.setup = function(app, controllers) {
app.get('/', controllers.index);
app.get('/posts', controllers.posts.index);
app.get('/posts/:post', controllers.posts.show);
// etc.
};
controllers/index.js:
exports.posts = require('./posts');
exports.index = function(req, res) {
// code
};
controllers/posts.js:
exports.index = function(req, res) {
// code
};
exports.show = function(req, res) {
// code
};
However, this setup has a big issue: I have a database- and an app-instance I need to pass to the actions (controllers/*.js). The only option I could think of, is making both variables global which isn't really a solution. I want to separate routes from the actions because I have a lot of routes and want them in a central place.
What's the best way to pass variables to the actions but separate the actions from the routes?
Use req.app, req.app.get('somekey')
The application variable created by calling express() is set on the request and response objects.
Node.js supports circular dependencies.
Making use of circular dependencies instead of require('./routes')(app) cleans up a lot of code and makes each module less interdependent on its loading file:
var app = module.exports = express(); //now app.js can be required to bring app into any file
//some app/middleware setup, etc, including
app.use(app.router);
require('./routes'); //module.exports must be defined before this line
var app = require('../app');
app.get('/', function(req, res, next) {
res.render('index');
});
//require in some other route files...each of which requires app independently
require('./user');
require('./blog');
Example from their new generator:
Writing the route:
https://github.com/expressjs/generator/blob/master/templates/js/routes/index.js
Adding/namespacing it to the app:
https://github.com/expressjs/generator/blob/master/templates/js/app.js#L24
There are still usecases for accessing app from other resources, so circular dependencies are still a valid solution.
Like I said in the comments, you can use a function as module.exports. A function is also an object, so you don't have to change your syntax.
app.js
var controllers = require('./controllers')({app: app});
controllers.js
module.exports = function(params)
{
return require('controllers/index')(params);
}
controllers/index.js
function controllers(params)
{
var app = params.app;
controllers.posts = require('./posts');
controllers.index = function(req, res) {
// code
};
}
module.exports = controllers;
For database separate out Data Access Service that will do all DB work with simple API and avoid shared state.
Separating routes.setup looks like overhead. I would prefer to place a configuration based routing instead. And configure routes in .json or with annotations.
Let's say that you have a folder named "contollers".
In your app.js you can put this code:
console.log("Loading controllers....");
var controllers = {};
var controllers_path = process.cwd() + '/controllers'
fs.readdirSync(controllers_path).forEach(function (file) {
if (file.indexOf('.js') != -1) {
controllers[file.split('.')[0]] = require(controllers_path + '/' + file)
}
});
console.log("Controllers loaded..............[ok]");
... and ...
router.get('/ping', controllers.ping.pinging);
in your controllers forlder you will have the file "ping.js" with this code:
exports.pinging = function(req, res, next){
console.log("ping ...");
}
And this is it....