Given together with Miguel Vega at the Open Source Health Care Alliance Conference (OSHCA) 2007

1. 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/

7. + =

13. 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 .

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

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

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

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

27. 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_

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

29. 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"]

30. 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

31. 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

38. ActiveRecord

39. 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'

40. 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 => [ &quot; name LIKE ? &quot; , &quot; The other guy &quot; ] # SELECT * FROM patients WHERE name = 'The other guy'

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

42. 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

43. 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

44. Or what people like to call Convention over Configuration

45. 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)

46. 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

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

51. 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 >