node.js practical guide to serverside javascript
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This document provides an overview of Node.js and how to build server-side JavaScript applications with it. Some key points covered include: - Node.js uses a single-threaded non-blocking I/O model that handles multiple requests concurrently using callbacks and an event loop. - Common Node.js modules like Express make it easy to build REST APIs and web servers. Express uses middleware for common tasks like routing, static files, authentication etc. - Testing Node.js applications can be done with frameworks like Mocha and Chai to write unit and integration tests, and the Request library to mock HTTP requests.
![express deep dive
middleware concept
request middleware
middleware
middleware
middleware
app.router
GET /
POST /profile
middleware
middleware
middleware
middleware
middleware
middleware
app.use(middleware);
app.use(middleware);
app.use(middleware);
app.use(express.router)
app.get('/',
middleware,
middleware,...,middleware)
app.post('/profile',
middleware,
middleware,...,middleware)
app.use(middleware);
app.use(middleware);
app.use(middleware);
authorization
app.get('/user/:id',
userAccessOnly,
featureAccess('getUser'),
getUser);
!
app.delete('/user/:id',
userAccessOnly,
featureAccess('deleteUser'),
deleteUser);
!
app.put('/profile',
userAccessOnly,
featureAccess('editProfile'),
validateProfile,
editProfile);
if(!req.user.features[feature]){
return
next(err.notAutorized())
}
if(!req.user){
return
next(err.noAuth());
}
next();
var
uid
=
req.param('id');
Users.delete(uid,
userGone);
function
userGone(err){
if(err)
next(err);
res.json({message:"OK"});
}](https://image.slidesharecdn.com/nodejs-lesson-130917054854-phpapp01/85/node-js-practical-guide-to-serverside-javascript-18-320.jpg)
node.js practical guide to serverside javascript
- 1. node.js practical guide to javascript on server
- 4. single threaded/non blocking OS thread f() f() f() f() f() iocall1 iocall2 callback1 callback2
- 5. heavy functions block server node worker worker worker worker so
- 6. what you shouldn't do with node? • real real time :) • data bending
- 7. without streams filesystem web nodeserver nodeserver filesystem web with streams readStream.pipe(writeStream) //file.pipe(response); fs.read('filename', function(data){ response.end(data); })
- 8. modules module.exports = function () {} ! all modules should be a single function var fs = require('fs'); fs.readFile('filename', function(data){console.log(data)}) npm install express -‐-‐save { "name":"pkgname", "version": "0.3.0", "author": "Eldar Djafarov <djkojb@gmail.com>", "dependencies":{ "express":"3.4.0" } }
- 9. npm scripts //use npm scripts { "scripts":{ "start":"node start.js", "test":"node test.js", "build":"grunt build", "build":"node ./node_modules/grunt-‐cli/.bin/grunt build" } } $ npm start // starts an app $ npm test // runs tests $ npm run build // builds an app
- 10. express deep dive simple nodejs server var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-‐Type': 'text/plain'}); res.end('Hello Worldn'); }).listen(1337, '127.0.0.1'); console.log('Server running at http://127.0.0.1:1337/'); simple express server var express = require('express'); var app = express(); app.use(function middleware(req, res, next){ // do stuff next(); }); app.get('/', function(req, res, next){ res.end('Hello Worldn'); }); app.listen(1337);
- 11. opinionated top level app architecture SPA REST API DB Angularjs or backbone node.js express mongoose mongodb
- 12. express rendering add engine app.engine('jade', require('jade').__express); app.engine('html', require('ejs').renderFile); render templates res.render('index', function(err, html){ res.send(html); }); res.render('user', { name: 'Tobi' }, function(err, html){ res.send(html); });
- 13. express deep dive middleware concept function middleware(req, res, next){ doAsyncStuff(asyncStuffDone); function asyncStuffDone(err, data){ if(err){ next(err); } next(); } } middleware middleware middleware middleware request response
- 14. express deep dive middleware concept request middleware middleware middleware middleware app.router GET / POST /profile middleware middleware middleware middleware middleware middleware app.use(middleware); app.use(middleware); app.use(middleware); app.use(express.router) app.get('/', middleware, middleware,...,middleware) app.post('/profile', middleware, middleware,...,middleware) app.use(middleware); app.use(middleware); app.use(middleware);
- 15. express deep dive middleware concept request middleware static middleware middleware app.router GET / POST /profile middleware middleware middleware middleware middleware middleware app.use(middleware); app.use(middleware); app.use(middleware); app.use(express.router) app.get('/', middleware, middleware,...,middleware) app.post('/profile', middleware, middleware,...,middleware) app.use(middleware); app.use(middleware); app.use(middleware); app.use(middleware); ! app.use(express.static('./public')); ! app.use(middleware); app.use(middleware); ! app.use('/static',express.static('./public')); ! app.use(middleware); or serve public with /static
- 16. express deep dive middleware concept request middleware middleware middleware middleware app.router GET / POST /profile middleware middleware middleware middleware middleware error middleware app.use(middleware); app.use(middleware); app.use(middleware); app.use(express.router) app.get('/', middleware, middleware,...,middleware) app.post('/profile', middleware, middleware,...,middleware) app.use(middleware); app.use(middleware); app.use(middleware); module.exports = function(err, req, res, next){ if(err){ if(err.isError){ return res.json(err.code, {err.reason}); } } res.json(500, { message: 'Something is terribly wrong' }); }
- 17. express deep dive middleware concept request middleware middleware auth middle middleware app.router GET / POST /profile middleware middleware middleware middleware middleware middleware app.use(middleware); app.use(middleware); app.use(middleware); app.use(express.router) app.get('/', middleware, middleware,...,middleware) app.post('/profile', middleware, middleware,...,middleware) app.use(middleware); app.use(middleware); app.use(middleware); authentication function authentication(req, res, next){ getUserBySessionId(req.session.uid, gotUser); function gotUser(err, user){ if(err) return next(err); if(!user){ req.user = "guest"; }else{ req.user = user; } next(); } }
- 18. express deep dive middleware concept request middleware middleware middleware middleware app.router GET / POST /profile middleware middleware middleware middleware middleware middleware app.use(middleware); app.use(middleware); app.use(middleware); app.use(express.router) app.get('/', middleware, middleware,...,middleware) app.post('/profile', middleware, middleware,...,middleware) app.use(middleware); app.use(middleware); app.use(middleware); authorization app.get('/user/:id', userAccessOnly, featureAccess('getUser'), getUser); ! app.delete('/user/:id', userAccessOnly, featureAccess('deleteUser'), deleteUser); ! app.put('/profile', userAccessOnly, featureAccess('editProfile'), validateProfile, editProfile); if(!req.user.features[feature]){ return next(err.notAutorized()) } if(!req.user){ return next(err.noAuth()); } next(); var uid = req.param('id'); Users.delete(uid, userGone); function userGone(err){ if(err) next(err); res.json({message:"OK"}); }
- 19. testing Use mocha + chai + request describe("User passes authentication", function(){ before(function(done){ request.post('/api/auth', {form:{login:login, pwd:password}}, authDone); function authDone(err, response, body){ expect(response).to.have.property('statusCode', 200); done(); } }) describe("GET /api/users tries to get all users", function(){ var users; before(function(done){ request.get('/api/users', gotUsers); function gotUsers(err, response, data){ users = data; } }) it('returned data should be json', function(){ users = JSON.parse(users); expect(users).to.be.an('object'); }); it('there should be > 5 users', function(){ expect(users).to.have.length.above(5); }) ... }) })
- 20. RESTful webservices Resources are nouns HTTP request types are verbs resource POST create GET read PUT update DELETE delete /dogs create new dog list dogs bulk update dogs bulk remove dogs /dogs/:id error read dog update dog if exists else error delete dog GET /dogs?color=red&state=running&location=park Complex stuff optional after ‘?’ sign bitly.com/restfulApi
- 21. environment Use flation/nconf module var APP_ENV = process.env.APP_ENV||'development'; nconf = require('nconf'); nconf.argv() .env() .file({file:'./config/'+APP_ENV+'.config.json'}); nconf.get('app:host'); nconf.get('app:port'); nconf.get('security:salt');