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:


• 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]




shutl mongob usergroup talk jan 2013

Technology

shutl accent grey

shutl main red

query proxy objects

shutl accent red

destroy triggers callbacks

ruby data types

index multiple keys

dark colour background