This document provides an overview of Node.js and Express. It discusses that Node.js is a JavaScript runtime for building asynchronous and event-driven servers. It allows JavaScript to run outside browsers for IO operations. The document also covers key aspects of the Node.js ecosystem like NPM, Connect middleware, and the popular web framework Express. It includes demos of building asynchronous servers, routing, templates, and integrating data models in Express apps.

1. Node.js
Express Yourself: Building Web
Applications with Node.js and Express
Yaniv Rodenski - @YRodenski

2. About me:
• Senior Architect @ Sela
• Windows Azure MVP
• Co-manager of the Windows Azure
Community
• Co-author of Developing Windows Azure and
Web Services (MOC 20487)
• Developing software professionally since 1997

3. About 1997:

4. About 1997:
Script-based server side
Shared hosting environment
Browser wars
New HTML standard that will
“Change the World”
This guy was the PM of Israel

5. Agenda
• What is Node.js
• The Importance of Being Asynchronous
• NPM
• Connect Middleware
• Express

6. What is Node.js
• A JavaScript runtime that is designed for
asynchronous IO operations
• Very lightweight and fast
• In use by a growing number of companies:

7. The Node.js Ecosystem
• Node.js has a rapidly growing ecosystem:
– Web frameworks:
• Express.js
• Socket.io
– Database support:
• MongoDB
• SQL Server
– Hosting and Cloud environments:
• IIS, Azure
• Forever.js
• Joyent, Heroku

8. Demo
Hello Node.js

9. Synchronous server operations
// GET api/countries
public string Get()
{
var client = WebRequest.Create("http://.../");
var response = client.GetResponse();
var stream = response.GetResponseStream();
var reader = new StreamReader(stream);
return reader.ReadToEnd();
}

10. Synchronous Server Operations
Client
DBServer
Client

11. Same-Same but Different
// GET api/countries
Public async Task<string> Get()
{
var client = new HttpClient();
var response = await client.GetAsync("http://...");
return await response.Content.ReadAsStringAsync();
}

12. Asynchronous Server Operations
Client
DBServer
Client

13. Demo
Async server in Node.js

14. Async JavaScript with Node.js
• Node.js is asynchronous by design
• Most IO operations have no synchronous API
• This is crucial since Node.js (or rather V8) has
a single thread

15. Node Package Manager (NPM)
• The Node Package Manager (NPM) provides a
management mechanism for modules
• Download and install
• Version management
• Deployment

16. Demo
Getting Express.js

17. Connect Middleware
• Node.js http module provides bare-bones HTTP server
functionality
• Connect middleware (by Sencha Labs) provides an expandable
pipeline on top of Node.js's httpServer
• You can add any functionality to the pipeline by calling the use
method, and passing a method:
server.use(function(req, res, next){
// some code
next();
})

18. Demo
Simple HTTP server using connect

19. Out-of-the-Box Middleware
Components
• Logging
• Body parser (JSON/forms)
• Cookies
• Error handling
• Session management
• Basic authentication

20. Demo
Using Cookies and Sessions

21. ExpressJS
• ExpressJS is a web application framework
inspired by Ruby’s Sinatra
• Provides a model-view-route architecture

22. Routing
• Routing is one of the pillars of ExpressJS
• To create a route use the app.verb
convention:
app.get('route',function(req,res){
});
app.post('route',function(req,res){
});
app.all('route',function(req,res){
});

23. Demo
Simple routing

24. Routing and Parameters
• Express supports parameters as part of the URI
• Declare a parameter in the URI using a
placeholder
• Access query-string parameters using req.query
• Use regular expression

25. Demo
Passing Parameters to Routes

26. Configuring Express
• Express provides the configure method to perform
configuration:
• Setting up Connect middleware
• Setting up application level variables using
app.set

27. Views
• Views are a template-based UI mechanism
• Express supports many view-engines
including:
• Jade
• JSHtml
• EJS

28. Jade
• Jade is Express’s default view engine
• It is based on Haml in order to provide a clean
syntax for generating HTML
• Tab based
• Full support for HTML

29. Demo
Basic Jade Template

30. Mixing Up JavaScript & Jade
• Jade fully supports JavaScript using the script
element:
• Linking to external JS files
• Embedding in-line JavaScript

31. Demo
Jade and bootstrap

32. Blocks
• In most applications, a number of UI
components are used throughout the
application
• Blocks provide a way to declare a common
layout that is shared among views

33. Demo
Using Blocks

34. ModelModel
• Express provides a mechanism to insert data-
models into views
• The rendering of the complete artifact is up to
the view engine

35. Demo
Rendering Data with Jade

36. Summary
• Node.js allows JavaScript
to run outside of browsers
and perform IO
• Asynchronous by nature
• Lightweight, fast and
extremely cool
• Rich ecosystem for
building JavaScript-based
servers

37. What’s next
• ExpressJS can be used to
use the MVR/MVC
patterns in web
applications
• Currently there are
1688 projects in NPM
which use Express: Sails,
Express.io, etc.
• All you need is a text
editor and a command line