Hidden gems in Ruby on Rails

Have you heard of a web framework called Ruby on Rails? There're a lot of stuff hidden under the hood of Ruby on Rails that you might not know about, and it might be really useful for you even if you aren't creating a web application. Let's not reimplement the wheel, and see what you can do if you include some part of Rails into your Ruby project.

Presented at RubyConf China 2013 on Oct 27, 2013.

Video is available at http://www.infoq.com/cn/presentations/hidden-gems-inside-those-of-Ruby-on-rails

Transcript

1. Hidden gems in Ruby on Rails
   

   View Slide

2. Prem Sichanugrist
   !
   !
   @sikachu
   /sikachu
   

   View Slide

3. View Slide

4. View Slide

5. ✈
   ️
   *57600x speed
   

   View Slide

6. 
   Flight attendance
   (Can speak Chinese)
   

   View Slide

7. 
   Me
   (Thai)
   Flight attendance
   (Can speak Chinese)
   

   View Slide

8. 
   

   (Cannot speak Chinese)
   Flight attendance
   (Can speak Chinese)
   Me

   

   View Slide

9. View Slide

10. 
    㟬૝ཁҰࠣ㠭佔吗?
    

    View Slide

11. View Slide

12. 
    Yes, I would like some coffee,
    please.
    

    View Slide

13. 
    㟬૝ཁҰࠣ䑊༉҃౶?
    

    View Slide

14. 
    㟬૝ཁҰࠣ䑊༉҃౶?
    

    View Slide

15. 
    Yes, cream and sugar is fine.
    

    View Slide

16. 
    谢谢
    

    View Slide

17. ☕
    

    View Slide

18. 
    䓟ཁෆཁ׃఺ॄ㜮?
    

    View Slide

19. 
    䓟ཁෆཁ׃఺ॄ㜮?
    
    

    View Slide

20. 
    㟬ت欢٣鸡೑҃ૉ৯?
    
    

    View Slide

21. 
    㟬ت欢٣鸡೑҃ૉ৯?
    
    
    

    View Slide

22. 
    㟬ت欢٣鸡೑҃ૉ৯?
    
    
    
    

    View Slide

23. 
    㟬ت欢٣鸡೑҃ૉ৯?
    
    
    
    
    

    View Slide

24. 
    㟬ت欢٣鸡೑҃ૉ৯?
    
    
    
    
    
    

    View Slide

25. View Slide

26. "Let's count how many
    people trying to speak
    Chinese to me"
    

    View Slide

27. "This is going to be fun"
    

    View Slide

28. 
    
    …
    

    View Slide

29. I lost my count
    

    View Slide

30. It feels great!
    

    View Slide

31. 谢谢
    

    View Slide

32. Hidden gems in Ruby on Rails
    

    View Slide

33. View Slide

34. View Slide

35. View Slide

36. View Slide

37. View Slide

38. View Slide

39. View Slide

40. "Rails is HUGE"
    

    View Slide

41. View Slide

42. View Slide

43. Rails is modular
    

    View Slide

44. Pick only part you use
    

    View Slide

45. "I'm not doing web
    application"
    

    View Slide

46. View Slide

47. Use Rails' components
    

    View Slide

48. Actively maintained
    

    View Slide

49. Fully tested
    

    View Slide

50. "I'll implement them myself"
    

    View Slide

51. gem  install  rails
    

    View Slide

52. Rails
    • Action Mailer
    • Action Pack
    • Active Record
    • Active Model
    • Active Support
    • Railties
    

    View Slide

53. Rails
    • Action Mailer
    • Action Pack
    • Active Record
    • Active Model
    • Active Support
    • Railties
    

    View Slide

54. gem  "mail"
    

    View Slide

55. Rails
    • Action Mailer
    • Action Pack
    • Active Record
    • Active Model
    • Active Support
    • Railties
    

    View Slide

56. Action Pack
    

    View Slide

57. Action Dispatch
    Middleware
    

    View Slide

58. [master][~/Projects/rails] ls \
    > actionpack/lib/action_dispatch/middleware
    callbacks.rb public_exceptions.rb ssl.rb
    cookies.rb reloader.rb stack.rb
    debug_exceptions.rb remote_ip.rb static.rb
    exception_wrapper.rb request_id.rb templates
    flash.rb session
    params_parser.rb show_exceptions.rb
    

    View Slide

59. ActionDispatch::ShowException
    Rescue and display the exception message
    

    View Slide

60. ActionDispatch::SSL
    Redirects all non-SSL requests to HTTPS
    

    View Slide

61. ActionDispatch::Static
    Serves static file in the path
    

    View Slide

62. Active Record
    

    View Slide

63. Pick one:
    • Active Record
    • DataMapper
    • Sequel
    • NoSQL varieties
    

    View Slide

64. Don't write raw
    SQL yourself
    

    View Slide

65. http://xkcd.com/327/
    

    View Slide

66. Active Model
    

    View Slide

67. ActiveModel::Model
    

    View Slide

68. Makes PORO acts

    like a model
    (PORO = Plain Old Ruby Object)
    

    View Slide

69. ActiveModel::Model
    • Naming helpers
    • I18n support
    • Validation
    

    View Slide

70. class  Person  
       include  ActiveModel::Model  
       attr_accesssor  :name,  :age  
    end  
       
    person  =  Person.new(name:  "Prem",  age:  27)  
    person.valid?  #=>  true  
    person.name  #=>  "Prem"
    

    View Slide

71. ActiveModel::Model
    • Naming helpers
    • I18n support
    • Validation
    

    View Slide

72. ActiveModel::Validations
    

    View Slide

73. Add validations to PORO
    

    View Slide

74. class  Person  
       include  ActiveModel::Validations  
       
       attr_accessor  :name,  :age  
       validates  :name,  presence:  true  
       validates  :age,  numericality:  true  
    end  
    !
    !
    !
    

    View Slide

75. class  Person  
       include  ActiveModel::Validations  
       
       attr_accessor  :name,  :age  
       validates  :name,  presence:  true  
       validates  :age,  numericality:  true  
    end  
    !
    person  =  Person.new  
    person.name  =  ""  
    person.valid?  #=>  false
    

    View Slide

76. Active Support
    

    View Slide

77. Core Extensions
    

    View Slide

78. String
    

    View Slide

79. String#inquiry
    

    View Slide

80. country  =  'china'  
    country  =  country.inquiry  
    !
    country.china?  #=>  true  
    country.usa?  #=>  false
    

    View Slide

81. String#squish
    

    View Slide

82. very_complex_sql  =  <    SELECT  *  
       FROM  posts  
       WHERE  state='published'  
    SQL  
    !
    #  =>  "    SELECT  *\n    FROM  posts\n    
    WHERE  state='published'\n"
    

    View Slide

83. very_complex_sql  =  <    SELECT  *  
       FROM  posts  
       WHERE  state='published'  
    SQL  
    !
    #  =>  "SELECT  *  FROM  posts  WHERE  
    state='published'"
    

    View Slide

84. String#strip_heredoc
    

    View Slide

85. content  =  <    Hello  
           World!  
    README  
    !
    #=>  "    Hello\n        World!\n"
    

    View Slide

86. class  FancyHello  
       def  initialize(user)  
           if  should_say_hello_to?  user  
               content  =  <                Hello  
                       World!  
               README  
           end  
       end  
    end  
    !
    #=>  "                Hello\n                    World!\
    

    View Slide

87. class  FancyHello  
       def  initialize(user)  
           if  should_say_hello_to?  user  
               content  =  <Hello  
       World!  
    README  
           end  
       end  
    end  
    !
    #=>  "Hello\n    World!\n"
    

    View Slide

88. content  =  <    Hello  
           World!  
    README  
    #=>  "Hello\n    World!\n"
    

    View Slide

89. String#to_date
    String#to_datetime
    String#to_time
    

    View Slide

90. Date.parse('2013-­‐10-­‐27')  
    #=>  Sun,  27  Oct  2013  
    '2013-­‐10-­‐27'.to_date  
    #=>  Sun,  27  Oct  2013  
       
    DateTime.parse('2013-­‐10-­‐27  09:40:00')  
    #=>  Sun,  27  Oct  2013  09:40:00  +0000  
    '2013-­‐10-­‐27  09:40:00'.to_datetime  
    #=>  Sun,  27  Oct  2013  09:40:00  +0000  
       
    Time.parse('09:40:00')  
    #=>  2013-­‐10-­‐27  09:40:00  +0800  
    '09:00:00'.to_time  
    #=>  2013-­‐10-­‐27  09:40:00  +0800
    

    View Slide

91. Hash
    

    View Slide

92. Hash#transform_keys
    

    View Slide

93. hash  =  {  foo:  'foo',  bar:  'bar'  }  
    #=>  {:foo=>"foo",  :bar=>"bar"}  
    !
    hash.transform_keys  {  |key|  
       key.to_s.capitalize  }  
    #=>  {"Foo"=>"foo",  "Bar"=>"bar"}
    

    View Slide

94. Array
    

    View Slide

95. Array#extract_options  
    Array#extract_options!
    

    View Slide

96. Keyword arguments
    Until we all using Ruby 2.0
    

    View Slide

97. #  say_hello("John",  "Jane",  language:  "zh-­‐CN")  
    def  say_hello(*names_or_options)  
       if  names_or_options.last.is_a?(Hash)  
           options  =  names_or_options.pop  
           names  =  names_or_options  
       else  
           options  =  {}  
           names  =  names_or_options  
       end  
       
       case  options[:language]  
       #  ...  
    

    View Slide

98. #  say_hello("John",  "Jane",  language:  "zh-­‐CN")  
    def  say_hello(*names)  
       options  =  names.extract_options!  
         
       case  options[:language]  
       #  ...  
    

    View Slide

99. #  say_hello("John",  "Jane",  language:  "zh-­‐CN")  
    def  say_hello(*names,  language:  "en-­‐US")  
       case  language  
       #  ...  
    !
    !
    

    View Slide

100. Array#in_groups
     

     View Slide

101. %w(1  2  3  4  5  6  7  8  9  10).in_groups(3)  
     #  =>  [  
     #            [1,  2,  3,  4],  
     #            [5,  6,  7,  nil],  
     #            [8,  9,  10,  nil]  
     #        ]
     

     View Slide

102. Array#in_groups_of
     

     View Slide

103. %w(1  2  3  4  5  6  7  8  9  10).in_groups_of(3)  
     #  =>  [  
     #            [1,  2,  3],  
     #            [4,  5,  6],  
     #            [7,  8,  9],  
     #            [10,  nil,  nil]  
     #        ]  
     

     View Slide

104. Object
     

     View Slide

105. Object#in?
     

     View Slide

106. STARTING_POKEMONS  =  %w(Chespin  Fennekin  Froakie)  
        
     if  STARTING_POKEMONS.include?(current_pokemon)  
        #  ...  
     end
     

     View Slide

107. STARTING_POKEMONS  =  %w(Chespin  Fennekin  Froakie)  
        
     if  current_pokemon.in?(STARTING_POKEMONS)  
        #  ...  
     end
     

     View Slide

108. Object#blank?  
     Object#present?
     

     View Slide

109. str  =  nil  
     str.nil?  #=>  true  
     str.empty?  #=>  NoMethodError  
     str.blank?  #=>  true  
     str.present?  #=>  false  
        
     str  =  ""  
     str.nil?  #=>  false  
     str.empty?  #=>  true  
     str.blank?  #=>  true  
     str.present?  #=>  false  
        
     str  =  "Hello"  
     str.nil?  #=>  false  
     str.empty?  #=>  false  
     str.blank?  #=>  false  
     str.present?  #=>  true
     

     View Slide

110. Disclaimer
     

     View Slide

111. Active Support is
     lazy-loaded
     

     View Slide

112. require  "active_support"
     

     View Slide

113. require  "active_support"  
     "Hello".inquiry  
     !
     

     View Slide

114. require  "active_support"  
     "Hello".inquiry  
     #=>  NoMethodError:  undefined  method  
     `inquiry'  for  "Hello":String
     

     View Slide

115. require  "active_support"  
     "Hello".inquiry  
     #=>  NoMethodError:  undefined  method  
     `inquiry'  for  "Hello":String
     
     

     View Slide

116. require  "active_support/all"
     

     View Slide

117. require  "active_support/all"
     
     

     View Slide

118. View Slide

119. View Slide

120. require  "active_support/core_ext/string/inquiry"
     

     View Slide

121. require  "active_support/core_ext/string"
     

     View Slide

122. http://guides.rubyonrails.org
     

     View Slide

123. Thank you!
     Prem Sichanugrist

     (@sikachu)
     http://learn.thoughtbot.com

     20% off promotion Code:
     RUBYCONFCHINA
     I also have some stickers
     

     View Slide