I've created a node application with express. I try to separate the following layers which will give me the ability to test the application with unit testing...
The problem is that I don't know how to call to the router.js file which will stops in the post/get/delete application.
The server.js file looks as follows
http = require('http'),
app = require('./app')(),
http.createServer(app).listen(app.get('port'), function (err) {
console.log('Express server listening on port ' + app.get('port'));
});
This is the app.js file
var express = require('express'),
logger = require('morgan'),
bodyParser = require('body-parser'),
routesApp = require('./ro/route');
module.exports = function () {
var app = express();
app.set('port', process.env.PORT || 3005);
app.use(logger('dev'));
app.use(function (req, res, next) {
res.set('APP', 'User app');
next();
});
app.use(bodyParser.json());
app.use(routesApp);
return app;
};
This is the router.js, which will route the call to other module according to the http type like post/delete/get etc...
var handleGet = require('../controller/handleGet');
var handlePost = require('../controller/handlePost');
var express = require('express');
module.exports = function (app) {
var appRoute = express.Router();
app.use(appRoute);
appRoute.route('*')
.post(function (req, res) {
handlePost(req, res);
})
.get(function (req, res) {
handleGet(req, res)
})
Currently I've two questions:
How to make it work since when in debug It dump in
app.use(appRoute); on the router.js file?
The error is TypeError: undefined is not a function
Is it good way to structure the node app like in my post? I want to seperate all this layers like SOC, I'm fairly new to node and express and I try to build it to be modular and testable...
How to make it work since when in debug It dump in app.use(appRoute); on the router.js file? The error is TypeError: undefined is not a function
This fails because you don't pass app into the module when you require it in app.js, you would need to do something like
app.use(routesApp(app)); // <- this hurts my eyes :(
Is it good way to structure the node app like in my post?I want to sperate all this leyrs like SOC,I fairly new to node and express and I try to build it to be modular and testable...
Your definitely on the right track, keeping things separated is generally always a good idea. Testing is definitely one of the big pluses but it also helps with other things like maintainability & debugging.
Personally, I would make use of the bin directory for any start up script configuration
bin/www
var app = require('./app');
app.set('port', process.env.PORT || 3005);
var server = app.listen(app.get('port'), function() {
console.log('Express server listening on port ' + app.get('port'));
});
This will help decouple your express app from all the environment setup. This should keep your app.js clean and only contain app-related config
app.js
var express = require('express')
, app = express()
, logger = require('morgan')
, bodyParser = require('body-parser')
, routes = require('./routes.js');
app.use(logger('dev'));
app.use(function (req, res, next) {
res.set('APP', 'User app');
next();
});
app.use(bodyParser.json());
app.use('/', routes);
...
module.exports = app;
Then finally, your routes.js should do nothing but handle your URLs
routes.js
var express = require('express')
, router = express.Router()
, handleGet = require('../controller/handleGet')
, handlePost = require('../controller/handlePost');
router.get('/', handleGet);
router.post('/', handlePost);
...
module.exports = router;
Related
I am new to Node.js. After watching many explanatory videos and and reading the Node.js docs, I started developing the site while respecting an MVC structure. The node server seems to work but the display on the front shows Cannot GET /. Here is the Browser Screenshot and the MVC structure of the project
index.js code :
'use strict';
/* eslint-env node, es6 */
const express = require('express');
const app = express();
app.set('view engine', 'ejs');
const PORT = process.env.PORT || 4242;
app.use('/', require('./routes/home_route'));
app.listen(PORT, () => {
console.log(`serveur démaré: localhost:${PORT}`);
});
home_controller.js code :
'use strict';
const homeView = (req, res) => {
res.render("home_view", {
} );
}
module.exports = { homeView };
home_route.js code :
'use strict';
const express = require('express');
const { homeView } = require('../controllers/home_controller');
const router = express.Router();
router.get('/home', homeView);
module.exports = router;
And home_view.ejs is just html. I don't understand where my mistake is, the code seems correct to me. Thank you in advance for your answers.
The problem is that you don't have any route handler for /. You are only handling /home. What you are saying with this line app.use('/', require('./routes/home_route')); is that every time I receive a request on /, I passe it to that router inside home_route.js, which only handles /home.
One way to solve this is to redirect the request you get on / to /home which is already handled. For that change home_route.js to:
const express = require('express');
const { homeView } = require('../controllers/home_controller');
const router = express.Router();
router.get('/home', homeView);
router.get('/', (req, res)=> res.redirect('/home')); // line I added
module.exports = router;
so I'm trying to make a simple "route system", that would handle requests and send them to a certain controller.
The problem is that I can't even handle any route, because I get
Cannot GET /
error in response.
app.js
const express = require('express')
const router = require('./routes/routes')
const app = express()
const port = 3000
app.engine('.html', require('ejs').__express)
app.set('view engine', 'html')
router.load()
app.listen(port, () => {
console.log(`Waiting on :${port}`)
})
routes.js
const express = require('express')
const app = express()
// Route config
const routes = {
['/']: {
controller: 'index',
method: 'get'
},
}
// Load routes
const load = () => {
for (const route in routes) {
app[routes[route].method](route, (req, res) => {
// Do something
})
}
}
exports.load = load
You don't use your router file in app.js, try that:
app.js
const express = require('express')
const router = require('./routes/routes')
const app = express()
const port = 3000
app.engine('.html', require('ejs').__express)
app.set('view engine', 'html')
app.use('/', router);
router.load()
app.listen(port, () => {
console.log(`Waiting on :${port}`)
})
routes.js
var express = require('express');
var router = express.Router();
router.get('/', function(req, res, next) { res.send({ success: true }); });
module.exports = router;
It's useless and unreadeable create an array whit your all your routes.
My suggestion is to try use command by terminal express my_app for generate the base structure and try to use it or at least read for see how it's work.
You seem to be lacking the context for how the routing system works within Express.
As a starting point, please create a project with the below structure, and try creating your own route to ensure you have a grasp on how to utilize them properly.
Create a new project folder
cd into the project folder from within your terminal
run npm init -y
Run npm i express dotenv
Create a file named app.js in the root of your project folder and place the below code inside of it:
require('dotenv').config();
const express = require('express');
const app = express();
app.use(express.json({limit: '30mb', extended: true}));
app.use(express.urlencoded({ extended: true }));
app.listen(process.env.PORT || 3000, () => {console.log('Server successfully started')});
app.get('/', (req, res) => {
return res.send('Hello, World!');
});
Create a new folder named routes
Create a new file named test.js and place it inside of the routes folder
Place the below code in the test.js file.
const router = require('express').Router();
router.get('/', (req, res) => {
return res.send('Hello from your custom route!');
});
module.exports = router;
Go back into your app.js file and add the below lines of code to the bottom of the file
const testRoute = require('./routes/test');
app.use('/test', testRoute);
In your terminal, run node app.js
Make a GET request to http://localhost:3000/test by navigating to it with your browser, or by using a REST client, such as Postman.
Once you have completed these steps, you should understand the basic concept of Express routing.
You can use the router combined with Express Middleware to re-route your user to the proper controller based on the endpoint they are trying to access / the data they are trying to send.
Please test with this code
const express = require('express')
const app = express();
app.get('/', (req, res) => {
res.json({"message": "Welcome! it's working"});
});
The complete code is here on Github
app.js
var express = require("express");
var app = express();
var path = require('path');
var db = require('./db');
var bodyParser = require('body-parser');
app.listen(80);
app.set('view engine', 'jade');
app.set('views', "./views");
// app.get('/', _GetMainPage);
// app.get('/sites', _GetSites);
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.urlencoded({ extended: true })); // Support encoded bodies
app.use(bodyParser.json()); // Support json encoded bodies
app.use(require('./controllers'));
./controllers/index.js
var express = require('express');
var router = express.Router();
router.use('/', require('./sites'));
router.use('/site', require('./site'));
module.exports = router;
./controllers/sites.js
var express = require('express');
var router = express.Router();
var site = require('../models/site');
router.get('/', function(req, res) {
site.getAll(function(err, rows){
if(err) {
res.send(err);
return;
}
res.render('sites', { sites : rows });
});
});
./controllers/site.js
var express = require('express');
var router = express.Router();
var site = require('../models/site');
router.get('/site', function(req, res) {
// console.log("get /site received. req.body: " + req.body);
res.render('site', {
site: {
name : req.params.name
}
});
});
module.exports = router;
When I request localhost/site I get a response saying:
Cannot GET /site
localhost/ works perfectly
I have been looking at this for a while and can't find the problem yet. If there is anything I can add, let me know. Thanks.
Thank you to the person that commented with the answer:
What happens if you navigate to /site/site? Your site.js route is relative to the route you provided in use. So it should be router.get('/' ... not router.get('/site' ...
The ./controllers/site route is already being routed to /site. On top of this I was calling router.get('/site', ...). This means it was actually routing to /site/site.
The solution is to just use router.get('/', ...) in the site.js file instead.
This really helped me, thank you.
Basically, the root path in the sub-app is defined in your core app where you mount it via the app.use() method.
the best example I can find from app.mountpath docs is here:
https://expressjs.com/en/4x/api.html#express.router
The app.mountpath property contains one or more path patterns on which a sub-app was mounted.
var express = require('express');
var app = express(); // the main app
var admin = express(); // the sub app
admin.get('/', function (req, res) {
console.log(admin.mountpath); // /admin
res.send('Admin Homepage');
});
app.use('/admin', admin); // mount the sub app
It is similar to the baseUrl property of the req object, except
req.baseUrl returns the matched URL path, instead of the matched
patterns.
If a sub-app is mounted on multiple path patterns, app.mountpath
returns the list of patterns it is mounted on, as shown in the
following example.
var admin = express();
admin.get('/', function (req, res) {
console.log(admin.mountpath); // [ '/adm*n', '/manager' ]
res.send('Admin Homepage');
});
var secret = express();
secret.get('/', function (req, res) {
console.log(secret.mountpath); // /secr*t
res.send('Admin Secret');
});
admin.use('/secr*t', secret); // load the 'secret' router on '/secr*t', on the 'admin' sub app
app.use(['/adm*n', '/manager'], admin); // load the 'admin' router on '/adm*n' and '/manager', on the parent app
I have this code:
var express = require("express");
var app = express();
var path = require("path");
app.use(express.static(__dirname + '/public'));
app.get('/',function(req,res){
res.sendFile(path.join(__dirname+'/views/index.html'));
res.set('Access-Control-Allow-Origin', '*');
}).listen(3000);
console.log("Running at Port 3000");
app.get('/test', function(req, res) {
res.json(200, {'test': 'it works!'})
})
I will have many services (like the test one), and I don't want to have them all on the same file.
I read in another question in Stack Overflow, that I can require other files like this: var express = require("./model/services.js"); And in that file write all the services, but it's throwing app is not defined when I start Node.
How can I separate codes?
You can define your routes in different files say test-routes.js like this:
module.exports = function (app) {
app.get('/test', function(req, res) {
res.json(200, {'test': 'it works!'})
})
}
Now in your main file say server.js you can import your route file like this:
var express = require("express");
var app = express();
var path = require("path");
app.use(express.static(__dirname + '/public'));
app.get('/',function(req,res){
res.sendFile(path.join(__dirname+'/views/index.html'));
res.set('Access-Control-Allow-Origin', '*');
}).listen(3000);
console.log("Running at Port 3000");
// import your routes
require('./test-routes.js')(app);
your test.js should look something like:
var express = require('express');
var router = express.Router();
router.get('/test', function (req, res) {
res.json(200, {'test': 'it works!'});
});
module.exports = router;
and the app.js (assuming other is some other route defined similarly to test.js):
var test = require("./routes/test.js");
var other = require("./routes/other.js");
...
//all your code for creating app
...
app.use('/test', test);
app.use('/other', other);
I have loads of router.get functions in my code which I think, could be reduced to a single switch-case function. Here is what I have tried:
function handlerA(req, res) {}
function handlerB(req, res) {}
var routes = {
'/url-one': handlerA,
'/url-two': handlerB
}
router.get('/*', function(req, res) {
var url = req.url;
if (routes[url]) {
routes[url](req, res);
}
});
This works but also, significantly slows my application. Is there any other solution which would not hit the performance of my app?
Thanks
Is there a reason you don't want to use router.get functions? I would guess express.js is internally performing the same logic that you are doing anyway. You are just replacing get functions with handlers.
If you are using similar logic between multiple routes, that may be worth abstracting.
I usually go with a setup like this:
app.js
routes.js
api/
user/
index.js
user.controller.js
user.model.js
image/
index.js
image.controller.js
image.model.js
/api/user/index.js:
var express = require('express');
var controller = require('./user.controller');
var router = express.Router();
router.get('/', controller.index);
router.post('/', controller.create);
module.exports = router;
/api/user/user.controller.js:
var User = require('./user.model');
exports.index = function(req, res) {
// Show list of users
};
exports.create = function (req, res, next) {
// Create user
};
/routes.js:
module.exports = function(app) {
// Insert routes below
app.use('/api/users', require('./api/user'));
app.use('/api/images', require('./api/image'));
// All undefined asset or api routes should return a 404
app.route('/:url(api|auth|components|app|bower_components|assets)/*')
.get(errors[404]);
// All other routes should redirect to the index.html
app.route('/*')
.get(function(req, res) {
res.sendfile(app.get('appPath') + '/index.html');
});
};
And lastly, the /app.js:
// Set default node environment to development
process.env.NODE_ENV = process.env.NODE_ENV || 'development';
var express = require('express');
var mongoose = require('mongoose');
var config = require('./config/environment');
// Connect to database
mongoose.connect(config.mongo.uri, config.mongo.options);
// Populate DB with sample data
if(config.seedDB) { require('./config/seed'); }
// Setup server
var app = express();
var server = require('http').createServer(app);
require('./config/express')(app);
require('./routes')(app);
// Start server
server.listen(config.port, config.ip, function () {
console.log('Express server listening on %d, in %s mode', config.port, app.get('env'));
});
// Expose app
exports = module.exports = app;
Most of this is directly from the Yeoman Generator Angular-Fullstack and it has a really nice setup!