Ruby on Rails

Ruby on Rails By Miguel Vega [email_address] http://www.upstrat.com/ and Ezwan Aizat bin Abdullah Faiz [email_address] http://rails.aizatto.com/ http://creativecommons.org/licenses/by/3.0/

Who Am I?
Miguel Vega
1 ½ years doing Ruby and Rails
PHP before then
Started a company (upstrat) just to have an excuse to use rails.

Who Am I?
Multiple Names
Ezwan Aizat Bin Abdullah Faiz
Aizat Faiz
aizatto
That scrubby looking guy on the screen
Student
Free and Open Source (FOSS) Enthusiast
Local FOSS Champion
http://foss.org.my
Web Developer
Ruby on Rails
LAMP

What is
Ruby on Rails?

Built on
Ruby Programming Language

Web Application Framework

Wait!
Unexpected
Side Effect!

Why Ruby?

A great man once said
Often people, especially computer engineers, focus on the machines .
They think,
“By doing this, the machine will run faster .
By doing this, the machine will run more effectively .
By doing this, the machine will something something something ”

They are focusing on machines . But in fact we need to focus on humans , on how humans care about doing programming or operating the application of the machines. We are the masters . They are the slaves .

By doing this,
the machine will something something something

We are the masters ,
they are the slaves
Yukihiro Matsumoto
Creator of Ruby

They are the SLAVES!

and I think we keep forgetting that

Ruby brings...

Large Increase in Productivity

How?
Non traditional programming style

Everything is an Object string = String .new 5 .times do puts " Hello World " end # Hello World # Hello World # Hello World # Hello World # Hello World

Everything is an Object 1 .upto( 100 ) { | i | puts i } # 1 # 2 # 3 # ... # 100 3.141_592_65 .ceil # 4 2.71828182845905 .floor # 2

Blocks (aka Closures) patients.each do | patient | if patient.ill? physician.examine patient else patient.jump_for_joy! end end

Blocks (aka Closures) hello = Proc .new do | string | puts " Hello #{string.upcase}" end hello.call ' Aizat ' # Hello AIZAT hello.call ' World ' # Hello WORLD

Open Classes class String def sanitize self .gsub( / [^a-z1-9]+ /i , ' _ ' ) end end puts " Ruby gives you alot of $$$ yo! " .sanitize # Ruby_gives_you_alot_of_yo_

Open Classes class Array def rand self [ Kernel ::rand(size)] end end puts %w[ a b c d e f g ] .rand # "e"

Open Classes class Array def shuffle size.downto( 1 ) { | n | push delete_at( Kernel ::rand(n)) } self end end puts %w[ a b c d e f g ] .shuffle.inspect # ["c", "e", "f", "g", "b", "d", "a"]

Open Classes class Numeric def seconds self end def minutes self .seconds * 60 end def hours self .minutes * 60 end def days self .hours * 24 end def weeks self .days * 7 end alias second seconds alias minute minutes alias hour hours alias day days alias week weeks end

Open Classes 1 .second # 1 1 .minute # 60 7.5 .minutes # 450.0 3 .hours # 10800 10.75 hours # 38700 24 .hours # 86400 31 .days # 2678400 51 .weeks # 30844800 365 .days # 31536000 Time .now # Thu May 10 12:10:00 0800 2007 Time .now - 5 .hours # Thu May 10 07:10:00 0800 2007 Time .now - 3 .days # Mon May 07 12:10:00 0800 2007 Time .now - 1 .week # Thu May 03 12:10:00 0800 2007

This is how Rails does its magic

and more...

What is Rails?
Convention over Configuration

MVC
Model View Controller

M VC

ActiveRecord
Object Relation Mapping (ORM)
Class to Table, Object to Row
CRUD simple
Database Agnostic

ActiveRecord

ActiveRecord::Base#find class Patient < ActiveRecord :: Base end Patient .find( 1 ) # SELECT * FROM patients WHERE id = 1 Patient .find_by_name ' Miguel Vega ' # SELECT * FROM patients WHERE name = 'Miguel Vega' Patient .find_by_date_of_birth ' 1986-07-24 ' # SELECT * FROM patients WHERE date_of_birth = '1986-07-24' Patient .find_by_name_and_date_of_birth ' Miguel Vega ' , ' 1986-07-24 ' # SELECT * FROM patients WHERE name = 'Miguel Vega' AND date_of_birth = '1986-07-24'

ActiveRecord::Base#find Patient .count # SELECT COUNT(*) AS count Patient .find :all , :order => ' name DESC ' # SELECT * FROM patients ORDER BY name DESC Patient .find :all , :conditions => [ " name LIKE ? " , " The other guy " ] # SELECT * FROM patients WHERE name = 'The other guy'

Models class Patient < ActiveRecord :: Base end class Encounter < ActiveRecord :: Base end class Physican < ActiveRecord :: Base end

Associations class Patient < ActiveRecord :: Base has_many :encounters has_many :physicans , :through => :encounters end class Encounter < ActiveRecord :: Base belongs_to :patient belongs_to :physician end class Physican < ActiveRecord :: Base has_many :encounters has_many :patients , :through => :encounters end

Smart Defaults class Patient < ActiveRecord :: Base has_many :encounters , :class_name => ' Encounter ' , :foreign_key => ' patient_id ' has_many :physicans , :through => :encounters , :class_name => ' Physician ' , :foreign_key => ' physician_id ' end class Encounter < ActiveRecord :: Base belongs_to :patient , :class_name => ' Patient ' , :foreign_key => ' patient_id ' belongs_to :physician , :class_name => ' Physician ' , :foreign_key => ' physician_id ' end class Physican < ActiveRecord :: Base has_many :encounters , :class_name => ' Encounter ' , :foreign_key => ' patient_id ' has_many :patients , :through => :encounters , :class_name => ' Patient ' , :foreign_key => ' patient_id ' end

Or what people like to call Convention over Configuration

Associations p = Patient .find :first # SELECT * FROM patients LIMIT 1 p.encounters.count # SELECT COUNT(*) AS count FROM encounters WHERE (patient_id = 1) p.encounters.find :condition => [ ' date <= ? ' Time .now - 12 .weeks] # SELECT * FROM encounters WHERE date <= '2007-02-13 16:19:29' AND (patient_id = 1)

Validations class Patient < ActiveRecord :: Base has_many :encounters has_many :physicans , :through => :encounters validates_presence_of :name validates_inclusion_of :gender , :in => [ ' male ' , ' female ' ] validates_email_of :email validates_numericality_of :age validates_confirmation_of :password end

MV C

ActionController
Separation of business logic and presentation
Ideally there should be no logic in the view

ActionController class PatientController < ApplicationController def index @patient = Patient .find :first @title = ' Patient Detail ' @homepage_title = " Patient: #{@patient.name}" end end

M V C

View < html > < head > < title > <%= @title %> </ title > </ head > < body > < h1 > <%= @homepage_title %> </ h1 > < b > Patient: </ b > < dl > < dt > Name </ dt > < dd > <%= @patient .name %> </ dd > </ dl > <%= render :partial => ' patient_details ' %> </ body > </ html >

Why Rails?

Convention over Configuration

Easy SQL
ActiveRecord::Base#find

Easy SQL
Even through associations

RAD/RID
Rapid Application Development
Rapid Iterative Development

Testing Framework
Built in Unit, Function, Integration testing

Awesome Plugin Structure

Simpler and Nicer looking Code

Web 2.0 Ready
Tagging, Folksonomy, Ajax, REST

Simply RESTful

DRY
Don't Repeat Yourself

DRY
Saves time
Easier to manage
Reusable Code
Best of all...

You don't look like a
code monkey

Most Importantly

Because it's
FUN

Questions?

Thank you
amcvega@gmail.com - aizat.faiz@gmail.com
Images used are from Tango Desktop Project http://tango.freedesktop.org/

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Ruby on Rails

by Aizat Faiz on May 12, 2007

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Ruby on Rails — Presentation Transcript