Develop Reference

Express node.js - understanding routing

I have this about.js route and it works fine but I don't understand how / in router.get() would work while /about wouldn't?
var express = require('express');
var router = express.Router();
router.get('/', function(req, res, next) {
res.render('about', { title: 'About' });
});
module.exports = router;
----------------- UPDATE ----------------------
It's basically what I got out of the box after installing express.js
except the about lines.
I expected router.get('/about' ...) in about.js would work but it threw an error and it worked with / instead and that's what bugs me.
app.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var routes = require('./routes/index');
var users = require('./routes/users');
var about = require('./routes/about');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
app.use('/about', about);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;

The problem
When you define a route on your app.js as you did with app.use('/about', about);. You are already telling express that you expect requests to hit http://yourserver/about route.
If you try to define /about again inside your about.js with:
router.get('/', function(req, res, next) {
res.render('about', { title: 'About' });
});
What you're doing is tellig the Express that you will hit a /about inside your firstly declared /about. So it will expect requests on this route: http://yourserver/about/about
The solution
It's actually what you're using. Define a root route inside your about.js as:
router.get('/', function(req, res, next) {
res.render('about', { title: 'About' });
});
This way your app will be:
Modular since you're using different files for different routes (about.js, users.js)
Easier to read
With simplier routes inside each file, since you don't need to type /about everytime you wish to create a new route.
If you wish a http://yourserver/about/help simply add a handler inside your route file about.js as here:
router.get('/help', function(req, res, next) {
res.render('help', { title: 'Help' });
});

If you want the route /about work then you have to create another route:
router.get('/about', function(req, res, next) {
res.render('about-page', { title: 'About' });
});
because / will only work for the home page.

Index page changed after clicking on the "Home" link

I'm using node.js, express and angular.js to make a personal blog. There is a link on the index page: Home. (It's in the layout.jade file as follows)
Everything is fine when I loaded the index page using the address http://localhost:8000/, ng-view loaded my contents correctly. But when I clicked the Home link, all the contents in ng-view just disappeared, I've been digging for a long time, but still couldn't figure out why.
My codes are as follows.
app.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var routes = require('./routes/index');
var api = require('./routes/api');
var fs = require('fs');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: false
}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/api', api);
app.get('/partials/:name', function (req, res) {
var name = req.params.name;
//res.render('partials/' + name);
res.render('partials/' + name);
});
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
routes/index.js (this is express routes, not angular.js)
var express = require('express');
var router = express.Router();
/* GET home page. */
router.get('/', function(req, res, next) {
res.render('index', { title: 'My Blog' });
});
module.exports = router;
routes.js (angular.js)
angular.module('blogApp', ['ngRoute']).
config(['$routeProvider', function($routeProvider) {
$routeProvider.
when('/', {
templateUrl: 'partials/index',
controller: IndexCtrl
});
}]);
index.jade
extends layout
block content
#main
#content
.ng-view
#side
...(omitted)
block scripts
link(rel='stylesheet', type='text/css', href='/stylesheets/index.css')
layout.jade
doctype html
html(ng-app='blogApp')
head
title=title
base(href='/')
link(rel='stylesheet', type='text/css', href='/stylesheets/vendors/bootstrap.min.css')
link(rel='stylesheet', type='text/css', href='/stylesheets/vendors/bootstrap-theme.css')
link(rel='stylesheet', type='text/css', href='/stylesheets/layout.css')
script(src='/javascripts/vendors/jquery-1.11.3.min.js')
script(src='/javascripts/vendors/jquery.form.js')
script(src='/javascripts/vendors/angular.js')
script(src='/javascripts/vendors/angular-route.js')
script(src='/javascripts/vendors/bootstrap.js')
script(src='/javascripts/vendors/satellizer.js')
script(src='/javascripts/views/login.js')
script(src='/javascripts/angular/controllers.js')
script(src='/javascripts/angular/routes.js')
body
#container
hgroup.header
h1 My Blog
#menu
ul
li
a(href='/') Home //Here is the link
li.nav-login
a(href='login') Login
block content
block scripts

You could try replacing the href attribute from the element with ng-href.
Home
to
<a ng-href="#/"> Home </a>
I think this will fix your problem.
and if you still having the same problem you could do a trick to make it possible by changing your routes.js as follows,
angular.module('blogApp', ['ngRoute']).
config(['$routeProvider', function($routeProvider) {
$routeProvider.
when('/', {
templateUrl: 'partials/index',
controller: IndexCtrl
})
.otherwise('/');
}]);
then try with any link in href ;)

Match your href for your home link to your actual local host url.
` Home

Node Express Routing Problems

I´m currently trying to render my .ejs-templates with some variables, but I´m kinda stuck and can`t help myself. I´ve installed express over the express-generator with compass and ejs.
In my routes/index.js
var express = require('express');
var router = express.Router();
/* GET home page. */
router.get('/', function(req, res, next) {
res.write('Hello World')
res.end();
});
module.exports = router;
So I want to render <%= name %> in index.ejs (views/index.ejs) with the name Jack. In a few tutorials it should work this way, but it just don`t works for me.
I got an error telling me that the variable name is not defined. Would be very nice, if you guys could tell me, what I´m doing wrong or what I´ve missed.
I´m using ejs the first time and just can`t figure out my mistake =/
This is my app.js server-file
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var http = require("http");
var routes = require('./routes/index');
var users = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(require('node-compass')({mode: 'expanded'}));
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
regards,
Cab
edit: I figured out that the rendering of the variable title works, but all the other variables don`t work. I can imagine, that I can only access some kind of global variables and title is one of them =/
edit2: Found out, that my routing isnt working properly ... so the rendering isnt working ofc. But can`t figure out my mistake =/

If you have split your project up into different modules then you need to export those modules so they are available in other parts of your app.
For example you have separate route modules where you are defining your routes. For these to be available to the rest of your app then you need to make them available using the module.exports command.
so at the end of routes/index.js you need to have
module.exports = router;
The end of the express page on routing gives an example

Basic nodejs route resulting in 404

I am trying to create two separate routes in NodeJS, I am using the express framework and angular on the client side. I am currently able to render my index page successfully by visiting localhost:3000/ although when I try to render the login page by visiting localhost:3000/login I am getting a GET /login 404 error and not sure why b/c I set it up extremely similar to the index route. Not sure if I missed something.
This my app.js
//require dependencies
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
//require routes but do not user yet
var routes = require('./routes/index');
var login = require('./routes/login');
//start app
var app = express();
// view engine setup - default views directory
app.set('views', path.join(__dirname, 'views'));
app.locals.delimiters = '<% %>';
app.set('view engine', 'hjs'); //use hogan templating for views
// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(require('less-middleware')(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/login', login);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
routes/login.js
var express = require('express');
var router = express.Router();
router.get('/login', function(req, res){
res.render('login');
});
module.exports = router;
views/login.hjs
<!DOCTYPE html>
<html>
<head>
</head>
<body>
HELLO WORLD
</body>
</html>
Visiting localhost:3000/login renders the following:
{{ message }}
{{ error.status }}
{{ error.stack }}

When writing app.use('/login', login), you are telling Express to use your router under the namespace : '/login'; Therefore, all routes defined into login.js don't need this prefix.
Try to access localhost:3000/login/login ;)
Then, just change your router to:
router.get('/', function(req, res){
res.render('login');
});

file upload in express js giving problems again

Though I have read quite a few questions being answered on stackoverflow, I'm still unable to get it to work even after a couple of days of trying. It's my first week with express and node and so I don't know if I'm doing the small things right. I basically want to upload a file and later on save it to the file system, however, I'm unable to proceed with req.files giving me undefined. Please see my code below.
This is my app.js
var express = require('express');
var path = require('path');
var favicon = require('static-favicon');
var logger = require('morgan');
var routes = require('./routes/index');
var users = require('./routes/users');
var upload = require('./routes/upload.js');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(favicon());
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
app.use('/upload', upload);
/// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
/// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
This is my routes/upload.js
var express = require('express');
var router = express.Router();
/* GET home page. */
router.get('/', function(req, res) {
console.log("");
console.log(req.files);
res.send('this is the page you get upon doing file upload');
});
module.exports = router;
This is my views/homepage.jade
doctype html
html
head
title= title
link(rel='stylesheet', href='/stylesheets/style.css')
body
p select file to upload
form(action="upload", method="get", enctype="multipart/form-data")
input(type="file", name="displayImage")
input(type="submit")
At the moment, I'm hearing a lot of terms like multer, connect-busboy, bodyParser being deprecated from express4 etc but with no real idea on how to proceed. Please advise me on how I can proceed and what code should be added.
Thanks.

You need a middleware module that can parse your uploaded file.
Like such:
https://github.com/expressjs/multer
https://github.com/mscdex/connect-busboy
Then use the middleware in your index.js, like:
app.use(multer({ dest: './uploads/'}))
or
app.use(busboy());

A number of modules were removed from Express in 4.0 and are now separate packages you have to include. The easiest way to get started with it is to use express-generator to generate the scaffolding for you. This will include and require the correct packages for parsing cookies, and the request body. It doesn't include a file parser however. I put together an example using multer and put it on Github for you to reference.
After you clone it, you can run npm install, and then npm start.
One other thing you were doing incorrectly that I fixed was using app.get for your upload handler. You can't use GET to upload a file. In my example I changed this to a POST request. Here are the relevant snippets.
app.js
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var multer = require('multer');
var routes = require('./routes/index');
var users = require('./routes/users');
var upload = require('./routes/upload');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');
app.use(multer({ dest: './uploads/'}))
// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
app.use('/upload', upload);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
module.exports = app;
index.jade
extends layout
block content
h1= title
p select file to upload
form(action='upload', method='post', enctype='multipart/form-data')
input(type='file', name='displayImage')
input(type='submit')