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
2. Prem Sichanugrist ! ! @sikachu /sikachu
5. ✈ ️ *57600x speed
6. Flight attendance (Can speak Chinese)
7. Me (Thai) Flight attendance (Can speak Chinese)
8. 
 (Cannot speak Chinese) Flight attendance (Can speak Chinese) Me

10. 㟬૝ཁҰࠣ㠭佔吗?
12. Yes, I would like some coffee, please.
13. 㟬૝ཁҰࠣ䑊༉҃౶?
14. 㟬૝ཁҰࠣ䑊༉҃౶?
15. Yes, cream and sugar is fine.
16. 谢谢
17. ☕
18. 䓟ཁෆཁ׃఺ॄ㜮?
19. 䓟ཁෆཁ׃఺ॄ㜮?
20. 㟬ت欢٣鸡೑҃ૉ৯?
21. 㟬ت欢٣鸡೑҃ૉ৯?
22. 㟬ت欢٣鸡೑҃ૉ৯?
23. 㟬ت欢٣鸡೑҃ૉ৯?
24. 㟬ت欢٣鸡೑҃ૉ৯?
26. "Let's count how many people trying to speak Chinese to me"
27. "This is going to be fun"
28. …
29. I lost my count
30. It feels great!
31. 谢谢
32. Hidden gems in Ruby on Rails
40. "Rails is HUGE"
43. Rails is modular
44. Pick only part you use
45. "I'm not doing web application"
47. Use Rails' components
48. Actively maintained
49. Fully tested
50. "I'll implement them myself"
51. gem  install  rails
52. Rails • Action Mailer • Action Pack • Active Record • Active Model • Active Support • Railties
53. Rails • Action Mailer • Action Pack • Active Record • Active Model • Active Support • Railties
54. gem  "mail"
55. Rails • Action Mailer • Action Pack • Active Record • Active Model • Active Support • Railties
56. Action Pack
57. Action Dispatch Middleware
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
59. ActionDispatch::ShowException Rescue and display the exception message
60. ActionDispatch::SSL Redirects all non-SSL requests to HTTPS
61. ActionDispatch::Static Serves static file in the path
62. Active Record
63. Pick one: • Active Record • DataMapper • Sequel • NoSQL varieties
64. Don't write raw SQL yourself
65. http://xkcd.com/327/
66. Active Model
67. ActiveModel::Model
68. Makes PORO acts
 like a model (PORO = Plain Old Ruby Object)
69. ActiveModel::Model • Naming helpers • I18n support • Validation
70. class  Person      include  ActiveModel::Model      attr_accesssor  :name,  :age   end       person  =  Person.new(name:  "Prem",  age:  27)   person.valid?  #=>  true   person.name  #=>  "Prem"
71. ActiveModel::Model • Naming helpers • I18n support • Validation
72. ActiveModel::Validations
73. Add validations to PORO
74. class  Person      include  ActiveModel::Validations          attr_accessor  :name,  :age      validates  :name,  presence:  true      validates  :age,  numericality:  true   end   ! ! !
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
76. Active Support
77. Core Extensions
78. String
79. String#inquiry
80. country  =  'china'   country  =  country.inquiry   ! country.china?  #=>  true   country.usa?  #=>  false
81. String#squish
82. very_complex_sql  =  <<-­‐SQL      SELECT  *      FROM  posts      WHERE  state='published'   SQL   ! #  =>  "    SELECT  *\n    FROM  posts\n     WHERE  state='published'\n"
83. very_complex_sql  =  <<-­‐SQL.squish      SELECT  *      FROM  posts      WHERE  state='published'   SQL   ! #  =>  "SELECT  *  FROM  posts  WHERE   state='published'"
84. String#strip_heredoc
85. content  =  <<-­‐README      Hello          World!   README   ! #=>  "    Hello\n        World!\n"
86. class  FancyHello      def  initialize(user)          if  should_say_hello_to?  user              content  =  <<-­‐README                  Hello                      World!              README          end      end   end   ! #=>  "                Hello\n                    World!\
87. class  FancyHello      def  initialize(user)          if  should_say_hello_to?  user              content  =  <<-­‐README   Hello      World!   README          end      end   end   ! #=>  "Hello\n    World!\n"
88. content  =  <<-­‐README.strip_heredoc      Hello          World!   README   #=>  "Hello\n    World!\n"
89. String#to_date
    String#to_datetime
    String#to_time
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
91. Hash
92. Hash#transform_keys
93. hash  =  {  foo:  'foo',  bar:  'bar'  }   #=>  {:foo=>"foo",  :bar=>"bar"}   ! hash.transform_keys  {  |key|      key.to_s.capitalize  }   #=>  {"Foo"=>"foo",  "Bar"=>"bar"}
94. Array
95. Array#extract_options   Array#extract_options!
96. Keyword arguments Until we all using Ruby 2.0
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]      #  ...  
98. #  say_hello("John",  "Jane",  language:  "zh-­‐CN")   def  say_hello(*names)      options  =  names.extract_options!            case  options[:language]      #  ...  
99. #  say_hello("John",  "Jane",  language:  "zh-­‐CN")   def  say_hello(*names,  language:  "en-­‐US")      case  language      #  ...   ! !
100. Array#in_groups
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]   #        ]
102. Array#in_groups_of
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]   #        ]  
104. Object
105. Object#in?
106. STARTING_POKEMONS  =  %w(Chespin  Fennekin  Froakie)       if  STARTING_POKEMONS.include?(current_pokemon)      #  ...   end
107. STARTING_POKEMONS  =  %w(Chespin  Fennekin  Froakie)       if  current_pokemon.in?(STARTING_POKEMONS)      #  ...   end
108. Object#blank?   Object#present?
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
110. Disclaimer
111. Active Support is lazy-loaded
112. require  "active_support"
113. require  "active_support"   "Hello".inquiry   !
114. require  "active_support"   "Hello".inquiry   #=>  NoMethodError:  undefined  method   `inquiry'  for  "Hello":String
115. require  "active_support"   "Hello".inquiry   #=>  NoMethodError:  undefined  method   `inquiry'  for  "Hello":String
116. require  "active_support/all"
117. require  "active_support/all"
120. require  "active_support/core_ext/string/inquiry"
121. require  "active_support/core_ext/string"
122. http://guides.rubyonrails.org
123. Thank you! Prem Sichanugrist
 (@sikachu) http://learn.thoughtbot.com
 20% off promotion Code: RUBYCONFCHINA I also have some stickers