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?
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;
// app.js
let db = ...; // your db object initialized
const contextMiddleware = (req, res, next) => {
req.db=db;
next();
};
app.use(contextMiddleware);
// routes.js It's just a mapping.
exports.routes = [
['/', controllers.index],
['/posts', controllers.posts.index],
['/posts/:post', controllers.posts.show]
];
// app.js
var { routes } = require('./routes');
routes.forEach(route => app.get(...route));
// You can customize this according to your own needs, like adding post request
The final app.js:
// app.js
var express = require('express');
var app = express.createServer();
let db = ...; // your db object initialized
const contextMiddleware = (req, res, next) => {
req.db=db;
next();
};
app.use(contextMiddleware);
var { routes } = require('./routes');
routes.forEach(route => app.get(...route));
app.listen(3000, function() {
console.log('Application is listening on port 3000');
});
Another version: you can customize this according to your own needs, like adding post request
// routes.js It's just a mapping.
let get = ({path, callback}) => ({app})=>{
app.get(path, callback);
}
let post = ({path, callback}) => ({app})=>{
app.post(path, callback);
}
let someFn = ({path, callback}) => ({app})=>{
// ...custom logic
app.get(path, callback);
}
exports.routes = [
get({path: '/', callback: controllers.index}),
post({path: '/posts', callback: controllers.posts.index}),
someFn({path: '/posts/:post', callback: controllers.posts.show}),
];
// app.js
var { routes } = require('./routes');
routes.forEach(route => route({app}));
If you want to pass an app-instance to others in Node-Typescript :
Option 1:
With the help of import (when importing)
//routes.ts
import { Application } from "express";
import { categoryRoute } from './routes/admin/category.route'
import { courseRoute } from './routes/admin/course.route';
const routing = (app: Application) => {
app.use('/api/admin/category', categoryRoute)
app.use('/api/admin/course', courseRoute)
}
export { routing }
Then import it and pass app:
import express, { Application } from 'express';
const app: Application = express();
import('./routes').then(m => m.routing(app))
Option 2: With the help of class
// index.ts
import express, { Application } from 'express';
import { Routes } from './routes';
const app: Application = express();
const rotues = new Routes(app)
...
Here we will access the app in the constructor of Routes Class
// routes.ts
import { Application } from 'express'
import { categoryRoute } from '../routes/admin/category.route'
import { courseRoute } from '../routes/admin/course.route';
class Routes {
constructor(private app: Application) {
this.apply();
}
private apply(): void {
this.app.use('/api/admin/category', categoryRoute)
this.app.use('/api/admin/course', courseRoute)
}
}
export { Routes }
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....
Or just do that:
var app = req.app
inside the Middleware you are using for these routes. Like that:
router.use( (req,res,next) => {
app = req.app;
next();
});
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.
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.
Source: Stackoverflow.com