Node.js with Expressweb application framework for node

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What is Express?

get '/' do redirect to('/hello/World')end get '/hello/:name' do "Hello #{params[:name]}!"end

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● Node.js web framework

● Sinatra-inspired

Getting started

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● npm install express

var express = require('express');

var app = express();

app.get('/hello', function(req, res){

res.send('Hello World');

});

app.listen(3000);

console.log('Listening on port 3000');

Getting started #2

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● npm install -g express

● express --sessions --css stylus --ejs myapp

● create : myapp

create : myapp/package.json

create : myapp/app.js

create : myapp/public

create : myapp/public/javascripts

create : myapp/public/images

create : myapp/public/stylesheets

create : myapp/public/stylesheets/style.styl

create : myapp/routes

create : myapp/routes/index.js

create : myapp/views

create : myapp/views/index.ejs

Configuration

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Used to separate production/development/etc... configurations (based on NODE_ENV)

// all environmentsapp.configure(function(){ app.set('title', 'Rescue');})

// development onlyapp.configure('development', function(){ app.set('mongoUrl', 'localhost/dev');})

// production onlyapp.configure('production', function(){ app.set('mongoUrl', 'n.n.n.n/prod');})

Middlewares

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● logging, auth, gzip, csrf protection, session management, etc...

● called sequentially, next() callback can trigger the next middleware

//built-in middlewaresapp.use(express.logger());app.use(express.compress());app.use(express.methodOverride());app.use(express.bodyParser());

//custom error handlingapp.use(function onError(err, req, res, next) { //do something with the error next(err);});

Routing

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app.VERB(path, [callback...], callback)

● GET, POST, PUT, DELETE, PATCH● [callback...] are middlewares

app.get(/^\/commits\/(\w+)(?:\.\.(\w+))?$/, function(req, res){

var from = req.params[0];

var to = req.params[1] || 'HEAD';

res.send('commit range ' + from + '..' + to);

});

Sessions

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● With middlewaresapp.use(express.cookieParser()); app.use(express.cookieParser('some secret'));

● For authentication use:○ Passportjs○ Everyauth

Rendering

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● With template engines: Mustache(hogan), Jade, EJS...

● Layout, views, partials● Variables are passed to the render engine

app.get('/', function(req, res) { res.locals = { title: 'Title', }; return res.render( 'index', { partials: { part: 'part', } } );});

Rendering #2

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● part.html<h1>{{ title }}</h1>

● index.html{{> part}} Hello world!