Build your first MongoDB App in Ruby @ StrangeLoop 2013

Building your rst
MongoDB Acaon

Agda
Introduction to MongoDB
MongoDB Fundamentals
Running MongoDB
Schema Design
Ruby & Sinatra Crash Course
Building Our First App

@spf13Steve Francia
AKA
Chief Developer Advocate @
responsible for drivers,
integrations, web & docs

* Document
* Open source
* High performance
* Horizontally scalable
* Full featured
MongoDB is a ___________ database

* Not for .PDF & .DOC files
* A document is essentially an associative
array
* Document == JSON object
* Document == PHP Array
* Document == Python Dict
* Document == Ruby Hash
* etc
Documt Database

* MongoDB is an open source
project
* On GitHub
* Licensed under the AGPL
* Commercial licenses available
* Contributions welcome
Op Source

* Written in C++
* Extensive use of memory-mapped files
i.e. read-through write-through memory
caching.
* Runs nearly everywhere
* Data serialized as BSON (fast parsing)
* Full support for primary & secondary indexes
* Document model = less work
High Pfoance

* Ad Hoc queries
* Real time aggregation
* Rich query capabilities
* Traditionally consistent
* Geospatial features
* Support for most programming languages
* Flexible schema
Full Ftured

Depth of Functionality
Scalability&Performance
Memcached
MongoDB
RDBMS
Database ndscape

tp://w.mongodb.org/downloads

K → Value
* One-dimensional storage
* Single value is a blob
* Query on key only
* No schema
* Value cannot be updated, only
replaced
Key Blob

Raonal
* Two-dimensional storage
(tuples)
* Each field contains a single
value
* Query on any field
* Very structured schema (table)
* In-place updates
* Normalization process requires
many tables, joins, indexes, and
poor data locality
Primary
Key

Documt
* N-dimensional storage
* Each field can contain 0, 1,
many, or embedded values
* Query on any field & level
* Flexible schema
* Inline updates *
* Embedding related data has optimal data
locality, requires fewer indexes, has better
performance
_id

user = {
username: 'fred.jones',
first_name: 'fred',
last_name: 'jones',
}
Sta wh an object
(or ay, hash, dict, c)

> db.users.insert(user)
Inst e record
No collection creation needed

> db.users.findOne()
{
"_id" : ObjectId("50804d0bd94ccab2da652599"),
"username" : "fred.jones",
"first_name" : "fred",
"last_name" : "jones"
}
Quying for e us

* _id is the primary key in MongoDB
* Automatically indexed
* Automatically created as an
ObjectId if not provided
* Any unique immutable value could
be used
_id

* ObjectId is a special 12 byte
value
* Guaranteed to be unique across
your cluster
* ObjectId("50804d0bd94ccab2da652599")
|-------------||---------||-----||----------|
ts mac pid inc
ObjectId

Tdaonal scha design
Focuses on data stoge

Documt scha design
Focuses on use

4 Building blocks
of Documt Design

exibi
* Choices for schema design
* Each record can have different fields
* Field names consistent for
programming
* Common structure can be enforced by
application
* Easy to evolve as needed

Ays
* Each field can be:
* Absent
* Set to null
* Set to a single value
* Set to an array of many values
* Query for any matching value
* Can be indexed and each value in the array
is in the index

beed Documts
* An acceptable value is a
document
* Nested documents provide
structure
* Query any field at any level
* Can be indexed

* Object in your model
* Associations with other entities
 Aßociaon
Referencing (Relational) Embedding (Document)
has_one embeds_one
belongs_to embedded_in
has_many embeds_many
has_and_belongs_to_many
MongoDB has both referencing and embedding for universal coverage

Excise 1:
Mod a busineß card

Contacts
{
“_id”: 2,
“name”: “Steven Jobs”,
“title”: “VP, New Product
Development”,
“company”: “Apple Computer”,
“phone”: “408-996-1010”,
“address_id”: 1
}
Rcing
Addresses
{
“_id”: 1,
“street”: “10260 Bandley Dr”,
“city”: “Cupertino”,
“state”: “CA”,
“zip_code”: ”95014”,
“country”: “USA”
}

Contacts
{
“_id”: 2,
Development”,
“address”: {
“zip_code”: ”95014”,
},
“phone”: “408-996-1010”
}
being

Excise 2:
Store a busineß card

Contacts
db.contacts.insert(
{
“_id”: 2,
Development”,
“phone”: “408-996-1010”,
“address_id”: 1
}
)
Insng wh Rce
Addresses
db.addresses.insert(
{
“_id”: 1,
“zip_code”: ”95014”,
}
)

Excise 3:
Re a busineß card

Contacts
c = db.contacts.findOne(
{
}
)
Quying wh Rce
Addresses
db.addresses.findOne(
{
“_id”: c.address_id,
“zip_code”: ”95014”,
}
)

Building a
MongoDB
Acaon

MongoDB has nave bindings
for nr allnguages

Official Support for 12 languages
Community drivers for tons more
Drivers connect to mongo servers
Drivers translate BSON into native types
mongo shell is not a driver, but works like
one in some ways
Installed using typical means (npm, pecl,
gem, pip)
MongoDB dvs

Build your first MongoDB App in Ruby @ StrangeLoop 2013

Building an a in Ruby?
Had to pick a language
Sinatra is very minimal and approachable
Wanted to focus on MongoDB interaction
Ruby gems are awesome
Works well on Windows, OS X & Linux
Seemed like a good idea at the time

hing is an object
1.class
'a'.class
:z.class
class Foo
end
Foo.class
Foo.new.class
# => Fixnum
# => String
# => Symbol
# => Class
# => Foo

Structure
Method
Class
Invocation
def do_stuff(thing)
thing.do_the_stuff
end
class TheThing
def do_the_stuff
puts "Stuff was done!"
end
end
do_stuff(TheThing.new)

Stngs
name = 'World' # => "World"
"Hello, #{name}" # => "Hello, World"
'Hello, #{name}' # => "Hello, #{name}"

Numbs
1 + 1 # => 2
1 + 1.1 # => 2.1
6 * 7 # => 42
6 ** 7 # => 279936
Math.sqrt(65536) # => 256.0
1.class # => Fixnum
(2 ** 42).class # => Fixnum
(2 ** 64).class # => Bignum
1.1.class # => Float

Ays
Array.new
Array.new(3)
[]
a = [1,2,3]
a[0] = 'one'
a
a[-1]
a[1..2]
# => []
# => [nil, nil, nil]
# => []
# => [1, 2, 3]
# => "one"
# => ["one", 2, 3]
# => 3
# => [2, 3]

Hashes
Hash.new
{}
h = {1 => "one", 2 => "two"}
h[1]
h["1"]
h[:one] = "einz"
h[:one]
h.keys
h.values
# => {}
# => {}
# => "one"
# => nil
# => "einz"
# => "einz"
# => [1, 2, :one]
# => ["one", "two", "einz"]

Vaables & Names
CamelCased # Classes, modules
with_underscores # methods, local variables
@instance_variable
@@class_variable
$GLOBAL_VARIABLE

Corol Structuresif condition
# ...
elsif other_condition
# ...
end
unless condition
# ...
end
while
# ...
end

Sinat is...
not Rails
not a framework
a DSL for quickly creating web
applications in Ruby with
minimal effort

Hlo World
# myapp.rb
require 'sinatra'
get '/' do
'Hello world!'
end

TP Acons
In Sinatra, a route is an HTTP method paired with a URL-matching
pattern.
Each route is associated with a block:
get '/' do
.. show something ..
end
post '/' do
.. create something ..
end
put '/' do
.. replace something ..
end
delete '/' do
.. annihilate something ..
end

Roes
Routes are matched in the order they are defined.
The first route that matches the request is invoked.
Route patterns may include named parameters,
accessible via the params hash:
get '/hello/:name' do
# matches "GET /hello/foo" and "GET /hello/bar"
# params[:name] is 'foo' or 'bar'
"Hello #{params[:name]}!"
end
#You can also access named parameters via block parameters:
get '/hello/:name' do |n|
"Hello #{n}!"
end

Spt
Route patterns may also include splat
(or wildcard) parameters, accessible via the
params[:splat] array:
get '/say/*/to/*' do
# matches /say/hello/to/world
params[:splat] # => ["hello", "world"]
end
get '/download/*.*' do
# matches /download/path/to/file.xml
params[:splat] # => ["path/to/file", "xml"]
end

Iroducing e mieu a

Download & Impo e vues
curl -L http://j.mp/StrangeLoopVenues |
mongoimport -d milieu -c venues
wget http://c.spf13.com/dl/StrangeLoopVenues.json
mongoimport -d milieu -c venues StrangeLoopVenues.json
Database
Collection

L’s lk at e vues
> use milieu
switched to db milieu
> db.venues.count()
50
Database

L’s lk at e vues
> db.venues.findOne()
{
"_id" : ObjectId("52335163695c9d31c2000001"),
"location" : {
"address" : "1820 Market St",
"distance" : 85,
"postalCode" : "63103",
"city" : "Saint Louis",
"state" : "MO",
"country" : "United States",
"cc" : "US",
"geo" : [
-90.20761747801353,
38.62893438211461
]
},
"name" : "St. Louis Union Station Hotel- A DoubleTree by Hilton",
"contact" : {
"phone" : "3146215262",
"formattedPhone" : "(314) 621-5262",
"url" : "http://www.stlunionstationhotel.com"
},
"stats" : {
"checkinsCount" : 0,
"usersCount" : 0
}
}

Crng a Geo index
> db.venues.ensureIndex({ 'location.geo' : '2d'})
> db.venues.getIndexes()
[
{
"v" : 1,
"key" : {
"_id" : 1
},
"ns" : "milieu.venues",
"name" : "_id_"
},
{
"v" : 1,
"key" : {
"location.geo" : "2d"
},
"ns" : "milieu.venues",
"name" : "location.geo_"
}
]

Sta wh a skon
/Users/steve/Code/milieu/app/
▸ config/
▸ helpers/
▾ model/
mongodb.rb
mongoModule.rb
user.rb
▾ public/
▸ bootstrap/
▾ css/
styles.css
▸ images/
▾ views/
footer.haml
index.haml
layout.haml
login.haml
navbar.haml
register.haml
user_dashboard.haml
user_profile.haml
venue.haml
venues.haml
app.rb
config.ru
Gemfile
Rakefile
README

Download & Install deps
mkdir milieu
cd milieu
wget http://c.spf13.com/dl/GettingStarted.tgz
tar zxvf GettingStarted.tgz
bundle install
Resolving dependencies...
Using bson (1.9.2)
Using bson_ext (1.9.2)
Using googlestaticmap (1.1.4)
Using tilt (1.4.1)
Using haml (4.0.3)
Using mongo (1.9.2)
Using rack (1.5.2)
Using rack-protection (1.5.0)
Using shotgun (0.9)
Using sinatra (1.4.3)
Using bundler (1.3.5)
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is
installed.

Run a
shotgun
== Shotgun/WEBrick on http://127.0.0.1:9393/
[2013-09-13 21:25:43] INFO WEBrick 1.3.1
[2013-09-13 21:25:43] INFO ruby 2.0.0 (2013-06-27)
[x86_64-darwin12.3.0]
[2013-09-13 21:25:43] INFO WEBrick::HTTPServer#start:
pid=85344 port=9393

Op Brows to locaost:9393

Connecng to MongoDB
require 'mongo'
require './model/mongoModule'
require './model/user'
# Connection code goes here
CONNECTION = Mongo::Connection.new("localhost")
DB = CONNECTION.db('milieu')
# Alias to collections goes here
USERS = DB['users']
VENUES = DB['venues']
CHECKINS = DB['checkins']
model/mongodb.rb

sng Vues
get '/venues' do
# Code to list all venues goes here
@venues = VENUES.░░░░░
haml :venues
end
app.rb

sng Vues
get '/venues' do
# Code to list all venues goes here
@venues = VENUES.find
haml :venues
end
app.rb

sng Vues
.container
.content
%h2 Venues
%table.table.table-striped
%thead
%tr
%th Name
%th Address
%th Longitude
%th Latitude
%tbody
~@venues.each do |venue|
%tr
%td
%a{:href => '/venue/' << venue['_id'].to_s}= venue['name']
%td= venue['location']['address'] ? venue['location']['address'] : '&nbsp'
%td= venue['location']['geo'][0].round(2)
views/venues.haml

sng Vueslocalhost:9393/venues

Paginang Vues
get '/venues/?:page?' do
@page = params.fetch('page', 1).to_i
pp = 10
@venues = VENUES.find.░░░░░(░░░░).░░░░(░░░)
@total_pages = (VENUES.░░░░░.to_i / pp).ceil
haml :venues
end
app.rb
# replaces the prior entry

Paginang Vues
get '/venues/?:page?' do
@page = params.fetch('page', 1).to_i
pp = 10
@venues = VENUES.find.skip((@page - 1) * pp).limit(pp)
@total_pages = (VENUES.count.to_i / pp).ceil
haml :venues
end
app.rb
# replaces the prior entry

.container
.content
%h2 Venues
%table.table.table-striped
%thead
%tr
%th Name
%th Address
%th Longitude
%th Latitude
%tbody
~@venues.each do |venue|
%tr
%td
%a{:href => '/venue/' << venue['_id'].to_s}= venue['name']
%td= venue['location']['address'] ? venue['location']['address'] : '&nbsp'
=pager('/venues')
sng Vues
views/venues.haml

paging rough Vueslocalhost:9393/venues

Crng Uss
Users are a bit special in our app
Not just data
Special considerations for secure
password handling
Not complicated on MongoDB side, but
slightly complicated on Ruby side

Crng Uss
class User
attr_accessor :_id, :name, :email, :email_hash, :salt, :hashed_password,
:collection, :updated_at
def init_collection
self.collection = 'users'
end
def password=(pass)
self.salt = random_string(10) unless self.salt
self.hashed_password = User.encrypt(pass, self.salt)
end
def save
col = DB[self.collection]
self.updated_at = Time.now
col.save(self.to_hash)
end
end
model/user.rb
Inherited from
MongoModule.rb

Crng Uss
post '/register' do
u = User.new
u.email = params[:email]
u.password = params[:password]
u.name = params[:name]
if u.save()
flash("User created")
session[:user] = User.auth( params["email"], params["password"])
redirect '/user/' << session[:user].email.to_s << "/dashboard"
else
tmp = []
u.errors.each do |e|
tmp << (e.join("<br/>"))
end
flash(tmp)
redirect '/create'
end
end
app.rb

Loing in pa 1
configure do
enable :sessions
end
before do
unless session[:user] == nil
@suser = session[:user]
end
end
get '/user/:email/dashboard' do
haml :user_dashboard
end
app.rb

Loing in pa 2
post '/login' do
if session[:user] = User.auth(params["email"], params["password"])
flash("Login successful")
redirect "/user/" << session[:user].email << "/dashboard"
else
flash("Login failed - Try again")
redirect '/login'
end
end
app.rb

Loing in pa 3
def self.auth(email, pass)
u = USERS.find_one("email" => email.downcase)
return nil if u.nil?
return User.new(u) if User.encrypt(
pass, u['salt']) == u['hashed_password']
nil
end
user.rb

Us Dashboard
.container
.content
.page-header
-unless @suser == nil?
%h2="Dashboard"
%br
%image{src: "http://www.gravatar.com/avatar/" <<
@suser.email_hash.to_s << '.png'}
%h3= @suser.name.to_s
-else
redirect '/'
%small
%a{href: "/user/" << @suser.email.to_s << "/profile"} profile
.container#main-topic-nav
views/user_dashboard.haml

Dashboard
localhost:9393/dashboard

nding a us
get '/user/:email/profile' do
u = USERS.░░░░░(
░░░░░ => ░░░░░.░░░░░)
if u == nil
return haml :profile_missing
else
@user = User.new(u)
end
haml :user_profile
end
app.rb

nding a us
get '/user/:email/profile' do
u = USERS.find_one(
"email" => params[:email].downcase)
if u == nil
return haml :profile_missing
else
@user = User.new(u)
end
haml :user_profile
end
app.rb

Crng an INdex
> db.users.ensureIndex({email : 1})
> db.users.getIndexes()
[
{
"v" : 1,
"key" : {
"_id" : 1
},
"ns" : "milieu.users",
"name" : "_id_"
},
{
"v" : 1,
"key" : {
"email" : 1
},
"ns" : "milieu.users",
"name" : "email_1"
}
]

Showing a Vue
get '/venue/:_id' do
object_id = ░░░░░░░░░░░░░░
@venue = ░░░░░░░░░░(
{ ░░░░ => object_id })
haml :venue
end
app.rb

Showing a Vue
object_id = BSON::ObjectId.from_string(params[:_id])
@venue = VENUES.find_one(
{ :_id => object_id })
haml :venue
end
app.rb

Showing a Vue
.row
.col-md-4
%h2= @venue['name'].to_s
%p
=@venue['location']['address'].to_s
%br= @venue['location']['city'].to_s +
' ' + @venue['location']['state'].to_s +
' ' + @venue['location']['postalCode'].to_s
.col-md-8
%image{:src => '' << gmap_url(@venue, {:height =>
300, :width => 450}) }
views/venue.haml

A Vue
localhost:9393/venue/{id}

Nrby Vues
object_id =
BSON::ObjectId.from_string(params[:_id])
@venue = VENUES.find_one({ :_id => object_id })
@nearby_venues = ░░░░░.░░░░░(
{░░░░░ =>{░░░░░=>[ ░░░░░,░░░░░]}}
).░░░░░(4).░░░░░(1)
haml :venue
end
app.rb

Nrby Vues
object_id =
@nearby_venues = VENUES.find(
{ :'location.geo' =>
{ ░░░░░ => [ ░░░░░,░░░░░]
}
}).░░░░░(4).░░░░░(1)
haml :venue
end
app.rb

Nrby Vues
object_id =
{ ░░░░░ => [ ░░░░░,░░░░░]
}
}).limit(4).skip(1)
haml :venue
end
app.rb

Nrby Vues
object_id =
{ :$near => [ @venue['location']['geo'][0],
@venue['location']['geo'][1]]
}
}).limit(4).skip(1)
haml :venue
end
app.rb

...
.row
- @nearby_venues.each do |nearby|
.col-md-3
%h2
%a{:href => '/venue/' + nearby['_id'].to_s}=
nearby['name'].to_s
%p
=nearby['location']['address'].to_s
%br= nearby['location']['city'].to_s +
' ' + nearby['location']['state'].to_s +
' ' + nearby['location']['postalCode'].to_s
%a{:href => '/venue/' + nearby['_id'].to_s}
%image{:src => '' << gmap_url(nearby, {:height
=> 150, :width => 150, :zoom => 17}) }
views/venue.haml
sng Nrby Vues

Nrby Vues
localhost:9393/venue/{id}

Checng in
get '/venue/:_id/checkin' do
user = USERS. ░░░░░_and_░░░░░(░░░░░)
if ░░░░░
░░░░░ ░░░░░ ░░░░░ ░░░░░
else
░░░░░ ░░░░░ ░░░░░ ░░░░░
end
flash('Thanks for checking in')
redirect '/venue/' + params[:_id]
end
app.rb

Checng in
user = USERS.find_and_modify(
:query => ░░░░░,
:update => ░░░░░,
:new => 1)
if ░░░░░
░░░░░ ░░░░░ ░░░░░ ░░░░░
else
░░░░░ ░░░░░ ░░░░░ ░░░░░
end
end
app.rb

Checng in
user = USERS.find_and_modify(
:query => { :_id => @suser._id},
:update => {:$inc =>{ "venues." << object_id.to_s => 1 } },
:new => 1)
if ░░░░░
░░░░░ ░░░░░ ░░░░░ ░░░░░
else
░░░░░ ░░░░░ ░░░░░ ░░░░░
end
end
app.rb

Checng in
user = USERS.find_and_modify(:query => { :_id => @suser._id},
:update => {:$inc =>
{ "venues." << object_id.to_s => 1 } }, :new => 1)
if user['venues'][params[:_id]] == 1
VENUES.update(░░░░░)
else
VENUES.update(░░░░░)
end
end
app.rb

Checng in
user = USERS.find_and_modify(:query => { :_id => @suser._id},
:update => {:$inc =>
{ "venues." << object_id.to_s => 1 } }, :new => 1)
if user['venues'][params[:_id]] == 1
VENUES.update({ :_id => @venue['_id']}, { :$inc =>
{ :'stats.usersCount' => 1, :'stats.checkinsCount' => 1}})
else
VENUES.update({ _id: @venue['_id']},
{ :$inc => { :'stats.checkinsCount' => 1}})
end
end
app.rb

You’ve be he
def user_times_at
if logged_in?
times = 'You have checked in here '
if !@suser.venues.nil? &&
!@suser.venues[params[:_id]].nil? times <<
@suser.venues[params[:_id]].to_s
else
times << '0'
end
times << ' times'
else
times = 'Please <a href='/login'>login</a> to
join them.'
end
end
helpers/milieu.rb

Checn In
%p
%a.btn.btn-primary.btn-large{:href =>
'/venue/' + @venue['_id'].to_s + '/checkin'}
Check In Here
%p
=@venue['stats']['usersCount'].ceil.to_s +
' users have checked in here ' +
@venue['stats']['checkinsCount'].ceil.to_s +
' times'
%p=user_times_at
views/venue.haml

A Vue localhost:9393/venue/{id}

What we’ve led
* Model data for
MongoDB
* Use MongoDB tools
to import data
* Create records from
shell & ruby
* Update records
* Atomic updates
* Create an index
* Create a geo index
* Query for data by
matching
* GeoQueries
* Pagination
* Single Document
Transactions
* Some ruby, sinatra,
haml, etc

Some Ids* Create interface to add venues
* Connect to foursquare
* Login w/twitter
* Badges or Categories
* Enable searching of venues
* Tips / Reviews

E IF YOU KED !
Questions?
http://spf13.com
http://github.com/spf13
@spf13

Build your first MongoDB App in Ruby @ StrangeLoop 2013

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