Node.js

Express.js + MongoDB

Sudo Soldiers
02.20.2014

Hi, I’m Karan.

• CS, UW
• Open web evangelist
• http://www.goel.im
• @TheKaranGoel

Sudo Soldiers

• https://www.facebook.com/groups/uwhackers/
• https://github.com/SudoSoldiers/
• http://students.washington.edu/uwsudo/
• uwsudo@uw.edu

On the menu

• Node.js
• Express.js
• MongoDB
• Live coding a web app

So, node.js?

• It's just Javascript.
• Server side JS on Google’s V8
• Write scalable web apps
• Single threaded
• Everything is asynchronous
• All I/O is non-blocking

What can you do with node.js

• JSON API's
• Single page apps
• Scalable web apps
• Interact with filesystems
• Data streaming
• Heavy computations
• General scripting

Who uses node.js

• Google
• Yahoo
• PayPal
• LinkedIn
• AirBnb
• A TON of startups

Projects, Applications, and Companies Using Node

Synchronous code

var data = readFromDatabase();
print(data);
doSomethingUnrelated();
					

Asynchronous code

readFromDatabase({
	print(data);
}
doSomethingUnrelated();
					

What Node isn't

• Full stack web framework
• MVC framework
• Pre-bundled with Database

Event loop

• Code runs in an "event loop"
• Stops only when no event listeners found

Hello world

cd p3/source/1/
node server.js
					

ExpressJS

• Web application framework for node
• Inspired by Sinatra (ruby)
• Provides high-level API access to Node
• npm install -g express

Hello world in ExpressJS

var express = require('express');

var app = express();

app.get('/hello.txt', function(req, res){
	res.send('Hello World');
});

app.listen(1337);
console.log('Listening on port 1337');
					

Connect Middleware

• Middleware is basically a function which accepts request and response objects and a next function.
• Connect is the heart of Express

express --help

  Usage: express [options] [dir]

  Options:

    -h, --help          output usage information
    -V, --version       output the version number
    -s, --sessions      add session support
    -e, --ejs           add ejs engine support (defaults to jade)
    -J, --jshtml        add jshtml engine support (defaults to jade)
    -H, --hogan         add hogan.js engine support
    -c, --css   add stylesheet  support (less|stylus) (defaults to plain css)
    -f, --force         force on non-empty directory
					

express -s
(cd p3/source/2)
npm install
node app.js
					

MongoDB

• NoSQL database
• Well documented, huge community
• Databases = Databases
• Collections = Tables
• Documents = Rows
• Nested documents

A Document

{
    _id: 1234,
    author: { name: "Bob Davis", email : "bob@bob.com" },
    date: { $date: "2010-07-12 13:23UTC" },
    location: [ -121.2322, 42.1223222 ],
    comments: [
       { user: "jgs32@hotmail.com",
         upVotes: 22,
         downVotes: 14,
         text: "Great point! I agree" },
       { user: "holly.davidson@gmail.com",
         upVotes: 421,
         downVotes: 22,
         text: "You are a moron" }
    ]
}
						

Quickstart

mongod 	// start the mongo server
mongo 	// start the CLI
help 	// show help contents
					

show collections
use newdb 	// make the DB on the fly
show collections 	// show the collections in the DB
db.collection1.save({1: 'a', 2: 'b'});
db.collection1.find(); 	// return all documents
db.collection1.find({1: 'a'}); 	// search for documents
					

Mongoose

• Mongoose extends native drivers to Node.js
• Define your own schema (models)

• npm install mongoose

Ok so let's make something

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What next

• MEAN stack
• Node is hard, but very fun
• Practice, a lot!

Resources

That is all.

@TheKaranGoel

Questions?