Shutl mongob usergroup talk jan 2013

MongoDB and Ruby

domain modeling with MongoMapper

Wednesday, 23 January 13

Volker Pacher

senior developer @shutl

@vpacher

http://github.com/vpacher






• SaaS platform


• SaaS platform

• we provide an API for carriers and merchants


• SaaS platform


• customers can chose between a delivery either:


• SaaS platform


• customers can chose between a delivery either: within 90 minutes of purchase


• SaaS platform


• customers can chose between a delivery either: within 90 minutes of purchase or a 1 hour window of their choice


• SaaS platform


• customers can chose between a delivery either: within 90 minutes of purchase or a 1 hour window of their choice (same day or any day)


• SaaS platform



• fastest delivery to date 14:00 min


• SaaS platform




• customers: Argos, Maplins, DrEd.com ...


• SaaS platform





• json api


• SaaS platform





• json api

•built with sinatra, jruby, neo4j and mongodb



5 Branding Guidelines

Logo Colours

The primary logo below contains the full title – Shutl. Wherever possible the rocket

should be present on the logo in Shutl Red as shown. It can also appear in black

where budget is a restraint.

Black on white Reverse (white) on darker tones

red on white red on lighter tones

Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:

The black logo should never

appear on in any ‘dark’ colour

background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%

Shutl Colour Palette:

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%


• install mongodb with brew install mongodb

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%



• in your gemfile:

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%




• gem ‘mongo’

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%




• gem ‘mongo’

• gem ‘bson’

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%




• gem ‘mongo’

• gem ‘bson’

• gem ‘bson_ext’

Let’s get going:



Logo Colours






Shutl Main Red:

Pantone 485 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Black:

Pantone BLACK

C0 M0 Y0 K0100

Please note:



background.

Shutl Accent Red:

Pantone 484 C

C0 M100 Y99 K4

R208 G31 B40

HEX D01F28

Shutl Accent Grey:

Pantone BLACK

C0 M0 Y0 K70

@ 70%




• gem ‘mongo’

• gem ‘bson’

• gem ‘bson_ext’

• run bundle install

Let’s get going:


MongoMapper


MongoMapper

• http://mongomapper.com/


http://mongomapper.com/


MongoMapper


• written by John Nunemaker (github)




MongoMapper


• written by John Nunemaker (github)

• code at https://github.com/jnunemaker/

mongomapper




https://github.com/jnunemaker/mongomapper




Alternatives:


Alternatives:

• Mongoid: http://mongoid.org/en/mongoid/index.html


http://mongoid.org/en/mongoid/index.html


Alternatives:


• MongoODM: https://github.com/carlosparamio/mongo_odm




https://github.com/carlosparamio/mongo_odm


Alternatives:


• MongoODM: https://github.com/carlosparamio/mongo_odm

• MongoModel: http://www.mongomodel.org/






http://www.mongomodel.org/

http://www.mongomodel.org/

installation:


installation:



installation:


• gem ‘mongo_mapper’


installation:


• gem ‘mongo_mapper’

• run bundle install


include MongoMapper

MongoMapper.connection = Mongo::Connection.new('localhost', 27017)MongoMapper.database = ‘development’

MongoMapper.database.authenticate('username','password')

db initialization:


class User include MongoMapper::Document

key :name, String, required: true key :age, Integer

one :address many :notes

timestamps!end

First document:


embedded document:

class Note include MongoMapper::EmbeddedDocument

key :text, Stringend


create a document:

user = User.new(name:'James Chester')user.notes.build(text:'a note')

user.save!

User.where(:name => 'James Chester').first


What is an embedded document?



• a document has it’s own collection in the database (table)




• an embedded document can only reside inside a document

or another embedded document






• the alternative in sql without join table would be to serialize






• the alternative in sql without join table would be to serialize

• in MongoDB it is possible to query inside embedded

documents and structures and also to index inside them


When to use embedded and when not to



• only embed when the document will be shown in the

context of the parent document





• if you need to access to the documents on it’s own use

associations (i.e. all notes)





• if you need to access to the documents on it’s own use

associations (i.e. all notes)

• they work the same way but declare a normal document

instead of an embedded one


{ id: '50fd8a786bcb608e1c000002',name: 'James Chester',address: {},notes: [ { id: '50fd8b246bcb608e1c000003', text: 'a note'}

]}


types:


types:

• mongomapper supports the ruby data types:

Integer, Float, String, Array, Hash, Object, Time, NilClass


types:



• additionally mongomapper adds support for:

Binary, Boolean, Date, ObjectId and Set


types:



• additionally mongomapper adds support for:

Binary, Boolean, Date, ObjectId and Set

• ability to add custom types


custom types:

class UpcaseString def self.to_mongo(value) value.nil? ? nil : value.to_s.upcase end

def self.from_mongo(value) to_mongo(value) endend


finding a document:


finding a document:

• find by id: User.find(‘50fd8a726bcb608e1c000001’)


finding a document:


• find by field: User.first(:name => 'James')


finding a document:



• query inside embedded document or structure (Hash)

User.all(‘address.postcode’ => 'EC2A 4HJ')


finding a document:



• query inside embedded document or structure (Hash)

User.all(‘address.postcode’ => 'EC2A 4HJ')

• finders are:

.find, .all, .first, .last, .paginate


dynamic querying:


dynamic querying:

• MongoMapper uses plucky to the allow the construction of query

proxy objects that only get executed when needed


dynamic querying:



• https://github.com/jnunemaker/plucky


https://github.com/jnunemaker/plucky


dynamic querying:




• User.where(:created_at.gte => 3.days.ago).sort(:created.desc)




dynamic querying:




• User.where(:created_at.gte => 3.days.ago).sort(:created.desc)• .where, .count, .field, .sort/.order, .limit,

.skip, .offset




operators:


operators:

• all mongodb operators can be used directly in mongomapper


operators:


• http://docs.mongodb.org/manual/reference/operators/


http://docs.mongodb.org/manual/reference/operators/


operators:



• User.where(:age => {:$gt => 20, :$lt => 45})




operators:




• or shorthand:




operators:




• or shorthand:

• User.where(:age.gt => 25)




destroy/delete:


destroy/delete:

• destroy triggers callbacks, delete does not


destroy/delete:


• User.destroy(‘50fd8a786bcb608e1c000002’)


destroy/delete:



• User.destroy_all


destroy/delete:



• User.destroy_all

• User.destroy_all(:age.gt => 25)


validations:

MongoMapper uses Rails ActiveModel:Validations

http://api.rubyonrails.org/classes/ActiveModel/Validations.html




class User include MongoMapper::Document

key :name, String, required: true key :age, Integer validates_numericality_of :age

validates :age_larger_18

def age_larger_18 errors.add( :age, "too young") if age < 18 endend


shorthands available:

:required – Boolean:unique – Boolean:numeric – Boolean:format – Regexp:in – Array:not_in – Array:length – Integer, Range, or Hash


indexes:


indexes: • put indexes into the initializer



• index on single field:

User.ensure_index(:name)





• index multiple keys:

User.ensure_index([[:name, 1], [:age, -1]])







• the order of keys is important in compound indexes








• unique index:

User.ensure_index [[:name, 1]], :unique => true








• unique index:

User.ensure_index [[:name, 1]], :unique => true• delete index: User.drop_index(:name)


using the decorator/presenter pattern for schemaless dbs

mongoDB

controller

retrieves object

decorator

‘decorates’ object for presentation

view

passes decorated object to view


Volker Pacher

[email protected]@vpacher

shutl.co.uk@shutl

Any questions?


mailto:[email protected]




Technology

Shutl mongob usergroup talk jan 2013