Refactoring towards Component-based Rails Architectures @ RailsConf 2014

You have a big Rails app and are feeling the pains? Stories are hard to deliver, code is hard to refactor, and your tests take a looong time? Getting you and your codebase out of this situation requires you to stop developing a "Rails application” and start refactoring towards your domain. I will discuss how and where you refactor towards a more structured and manageable application, a component-based Rails architecture.

Transcript

1. Big Rails
   

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2. https://github.com/josh-jacobson/Wedloom
   

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3. Refactoring towards Component-
   based Rails Architectures
   Stephan Hagemann
   !
   Pivotal Labs
   Boulder, CO
   

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4. Component-based Rails architectures
   

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5. #cbra
   

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8. github.com/shageman/the_next_big_thing
   

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9. Teaser
   Email
   Signup
   Annoyance
   Event
   Counter
   Rails Container
   

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10. Proxy
    Partner API
    Rails Container
    Registration
    Internal API
    

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11. Availability and
    Booking
    Rails Travel Site
    Payment
    Gateway
    Conversion
    Tracking
    

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12. Rails TV Shows with Social Network
    Global Admin Show Admin
    SMS Interface
    Social Network
    Publisher
    Admin UI
    Users and
    Channels
    

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14. WAT?
    

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15. Because it helps
    

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16. How to write #cbra?
    github.com/shageman/the_next_big_thing
    !
    http://pivotallabs.com/tag/rails-application-suites/
    !
    confreaks.com/presenters/790-stephan-hagemann
    confreaks.com/presenters/784-ben-smith
    !
    https://leanpub.com/cbra
    

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17. Big Rails
    

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19. How Big?
    find . -iname "*.rb" -type f -exec cat {} \; | wc -l
    

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20. How Big?
    gist.github.com/shageman/11185993
    

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23. Growing size
    

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26. Exploding complexity
    Size
    Possible
    Interactions
    

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27. Versions of Large
    VS
    

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30. Size
    Possible
    Interactions
    Reduced (Exploding) complexity
    

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32. the rich get richer and the poor get
    

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33. - “Ain't We Got Fun?” - Gus Kahn, Raymond B. Egan
    the rich get richer and the poor get—children!
    

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34. Preferential Attachment
    

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35. Entities (sorted by size)
    Size
    

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36. Big Open-Source Rails Apps
    browsercms!
    calagator!
    canvas-lms!
    citizenry!
    diaspora
    opencongress!
    opengovernment!
    portlandcrime!
    railscollab!
    rubygems.org
    locomotivecms!
    fat_free_crm!
    fulcrum!
    loc_counts!
    onebody
    skyline!
    snorby!
    spot-us!
    spree!
    teambox
    tracks
    

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37. What About Code?
    find . -iname "*.rb" -type f -exec wc -l {} \; | sort -rn
    

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38. What About Code?
    https://gist.github.com/shageman/11190909
    

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41. user.rb
    

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43. ActiveRecord Associations
    

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44. has_many
    

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45. users model
    

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46. id name home
    1 Kate Chicago
    2 Pete Boulder
    3 Ian Boulder
    4 Sam Chicago
    users table
    users model
    

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47. id name code
    1 red #FF0000
    2 green #00FF00
    3 blue #0000FF
    4 yellow #FFFF00
    colors table
    colors model
    

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48. How many has many?
    ack " has_many " -c | awk -F ":" '{print $2,$1}' | grep -v "0" | sort -rn
    

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49. How many has many?
    https://gist.github.com/shageman/11191030
    

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52. user.rb
    

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56. we can do better
    

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61. SOLID
    

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62. Single Responsibility Principle
    

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63. Things that don’t belong
    

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64. SRP - where?
    Method
    Class
    Module
    Yes!
    Yes!
    

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65. SRP - where?
    Method
    Class
    Namespace
    Yes!
    Yes!
    

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66. Mixins
    

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67. SRP - where?
    Method
    Class
    Namespace
    Component
    Application
    Now you can!
    Yes!
    Yes!
    You should! … Anyone?
    You should!
    

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68. Components over SOAs
    1 repo
    1 test suite (and splittable!)
    1 deployment
    no additional versioning constraints
    easier refactorings between parts
    

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69. Within a SOA componentize your apps
    

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70. Refactoring towards #cbra
    

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72. Teasing out App Component
    Extracting Functional Component
    

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73. https://leanpub.com/cbra
    

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74. Teasing out App Component
    

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75. Teasing out App Component
    0. Got tests?
    

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76. Teasing out App Component
    1. Find a vertical that makes sense on its own
    V
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    M
    

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77. Teasing out App Component
    2. Namespace controllers, views, and models
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78. Teasing out App Component
    2. Namespace controllers, views, and models
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    M
    

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79. Teasing out App Component
    3. Hunt down other dependencies
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    M
    

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80. Teasing out App Component
    4. Move all namespaced code into an engine
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81. Teasing out App Component
    4b. rails plugin new MY_NEW_COMPONENT --full --mountable
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82. Teasing out App Component
    Step 3. PROFIT!
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    M
    

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83. Teasing out App Component
    PROTIP: Special Case
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    M
    

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84. Extracting Functional Component
    

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85. Extracting Functional Component
    0. Got tests?
    

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86. Extracting Functional Component
    1. Find functional component
    

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87. Extracting Functional Component
    2. bundle gem MY_NEW_COMPONENT
    

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88. Extracting Functional Component
    3. move all files into gem (and namespace)
    

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89. Extracting Functional Component
    4. move the other stuff the gem needs
    

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90. Extracting Functional Component
    5. Require the gem from your app
    

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91. Extracting Functional Component
    6. Add shims/ports/adapters to make the app happy
    

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92. Extracting Functional Component
    Step 3. PROFIT!
    

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94. I will help
    @shageman
    

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97. Thanks!
    @shageman
    

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