Building web apps with Express

Building web apps with Express Andy Appleton @appltn http://appleton.me

Express is a simple web application framework http://expressjs.com/

...built on Connect, the middleware framework http://www.senchalabs.org/connect/

Connect provides a bunch of handy utilities for dealing with
HTTP requests

var app = connect() .use(connect.logger('dev')) .use(connect.static('public')) .use(function(req, res){ res.end('hello world\n');
}) .listen(3000);

But anyway, Express

$ npm install -g express Install express globally

$ npm install -g express Init a new express app
in ./awesome-demo $ express awesome-demo

$ npm install -g express Install the app’s dependencies with
npm $ express awesome-demo $ cd awesome-demo && npm install

$ npm install -g express Run it! $ express awesome-demo
$ cd awesome-demo && npm install $ node app.js >> Express server listening on port 3000

var express = require('express'); ... var app = express();

// Get & set an app property app.set('name', 'value'); //
Use a middleware function app.use(myMiddlewareFunction()); // Respond to an HTTP request app.get('/path', callbackFn); app.post('/path', callbackFn); app.put('/path', callbackFn); // ...etc

Routing

app.get('/', routes.index); app.get('/users', routes.users.index); app.get('/users/:id', routes.users.show); app.post('/users/:id', routes.users.create); app.put('/users/:id', routes.users.update);

Handling a route // /users routes.index = function(req, res) {
res.send('Hello Bath'); }; // /users/:id routes.users.show = function(req, res) { var userId = req.params.id; res.send('Your userId is ' + userId); };

Rendering HTML templates

Rendering HTML templates routes.index = function(req, res) { res.render('index'); };
routes.users.show = function(req, res) { var userId = req.params.id; res.render('users/show', { id: userId }); };

doctype 5 html head ... body block content extends layout
block content h1= title p Welcome to #{title} ./views/layout.jade ./views/index.jade

"dependencies": { ... "hbs": "*" } ./package.json $ npm install
./app.js app.configure(function(){ ... app.set('view engine', 'hbs'); ... }); app.configure(function(){ ... app.set('view engine', 'jade'); ... });

<!DOCTYPE html> <html> <head>...</head> <body> {{{body}}} </body> </html> ./views/layout.hbs ./views/index.hbs
<h1>{{title}}</h1> <p>Welcome to {{title}}</p>

routes.index = function(req, res) { res.render('index'); }; routes.users.show = function(req,
res) { var userId = req.params.id; res.render('users/show', { id: userId }); };

Sessions

// must come before router app.use(express.cookieParser('secret')); app.use(express.session()); app.use(app.router); Session support
is middleware

routes.users.show = function(req, res) { req.session.id || (req.session.id = 1);
res.render('users/show', { id: req.session.id }); };

Andy Appleton @appltn http://appleton.me

Building web apps with Express

Building web apps with Express

Andy Appleton

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