Rails Magic Exposed

Rails Magic Exposed

The Ruby that powers Rails.. LoneStarRubyConf 2012

3b5cb0411cbd1012acab1b60f7ce3606?s=128

Jesse Wolgamott

August 11, 2012
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  1. Rails magic Saturday, August 11, 12

  2. EPFT NBHJD FYJTU Saturday, August 11, 12

  3. MFU`TBTL 4$*&/$& Saturday, August 11, 12

  4. (PPHMF 3FTVMUT Saturday, August 11, 12

  5. Framework Magic Total php (1994) 132000 2.527E+10 java (1995) 45900

    960000000 .net (2002) 4400 250000000 django (2004) 9370 44300000 rails (2005) 7040 20300000 Saturday, August 11, 12
  6. .BHJD3BUJP w1)1 w+BWB w/&5 Saturday, August 11, 12

  7. .BHJD3BUJP w%KBOHP w3BJMT Saturday, August 11, 12

  8. 0 1 2 3 4 php (1994) java (1995) .net

    (2002) django (2004) rails (2005) 0.052 0.478 0.176 2.115 3.468 Magic over Time Frequency / 10000 Saturday, August 11, 12
  9. 0 1 2 3 4 php (1994) java (1995) .net

    (2002) django (2004) rails (2005) Node 0.052 0.478 0.176 2.115 3.468 2.031 A Step Back Saturday, August 11, 12
  10. 0 100 200 300 400 php (1994) .net (2002) rails

    (2005) Meteor.js 0.052 0.478 0.176 2.115 3.468 2.031 345.810 MAGIC of Meteor Saturday, August 11, 12
  11. l"OZTVGpDJFOUMZ BEWBODFE UFDIOPMPHZJT JOEJTUJOHVJTIBCMF GSPNNBHJDz "SUIVS$$MBSL Saturday, August 11, 12

  12. dynamic finders Saturday, August 11, 12

  13. id = params[:customer_id] YourModel.find_by_customer_id id Saturday, August 11, 12

  14. def method_missing(method_id, *arguments) if match = /find_(all_by|by)_([_a-zA-Z]\w*)/. match(method_id.to_s) # find...

    elsif match = /find_or_create_by_([_a-zA-Z] \w*)/. match(method_id.to_s) # find_or_create... else super end end Saturday, August 11, 12
  15. magic columns Saturday, August 11, 12

  16. created_at and updated_at counter_caches type Saturday, August 11, 12

  17. def apply_it(items) items.map do |item| item.apply! if item.respond_to? (:apply!) end

    end Saturday, August 11, 12
  18. Active Record definition Saturday, August 11, 12

  19. class User < ActiveRecord::Base has_many :posts has_many :comments, through: :posts

    validates_presence_of :email end Saturday, August 11, 12
  20. class SuperWo 20.times {|i| puts "This is the #{i}”} def

    wat! puts "hi" end end SuperWo.new.wat! Try it out: http://rubyfiddle.com/riddles/a63dd Saturday, August 11, 12
  21. auto loading Saturday, August 11, 12

  22. Dir.glob('./app/models/*').each do |file| require file end require_relative 'db/setup' require_relative 'models/page'

    require_relative 'models/book' Saturday, August 11, 12
  23. CFDBVTF "DUJWF4VQQPSU %FQFOEFODJFT VSM IUUQSLIJN DPEFSFMPBEJOH Saturday, August 11, 12

  24. # Extremely simple autoloading implementation class Module alias const_missing_without_autoloading const_missing

    def const_missing(const) path = “./#{name.gsub('::', '/')}/#{const}" path.gsub!(/([a-z\d])([A-Z])/,'\1_\2') require path.downcase const_defined?(const) ? const_get(const) : super rescue LoadError => error warn(error.message) super end end Saturday, August 11, 12
  25. "VUP-PBEJO"DUJPO HJUIVCKXP DMPBLFEUZSJPO Saturday, August 11, 12

  26. 4PNVDINPSF Saturday, August 11, 12

  27. class Foo @@foo ||= 42 puts @@foo # 42 end

    # reload... class Foo @@foo ||= 23 puts @@foo # 42 end Saturday, August 11, 12
  28. # reload... Object.send(:remove_const, :Foo) class Foo @@foo ||= 23 puts

    @@foo # 23 end Saturday, August 11, 12
  29. custom ruby Saturday, August 11, 12

  30. NPOLFZQBUDIJOH Saturday, August 11, 12

  31. numbers = (1..100).to_a numbers.first numbers.last numbers.forty_two Saturday, August 11, 12

  32. def forty_two self[41] end "MTPLOPXOBTBDDFTTJOHUIF SFEEJU Saturday, August 11, 12

  33. class Enumerable def standard_dev Math.sqrt(sample_variance) end def sample_variance mean =

    sum.to_f / size.to_f sum{|i| (i-mean)**2} / size end end Saturday, August 11, 12
  34. review Saturday, August 11, 12

  35. EZOBNJD@pOEFST NFUIPE@NJTTJOH Saturday, August 11, 12

  36. NBHJD@DPMVNOT SFTQPOE@UP Saturday, August 11, 12

  37. BS@EFpOJUJPOT DPNQJMF@UJNF@DPEF Saturday, August 11, 12

  38. BVUP@MPBEJOH DPOTU@NJTTJOH Saturday, August 11, 12

  39. NPOLFZ@QBUDIJOH PQFO@DMBTTFT Saturday, August 11, 12

  40. @@jwo ruby off rails Saturday, August 11, 12