DCI with Ruby

DCI の使い方を考える

Transcript

1. DCI with
   Ruby
   わかった気になる DCI
   

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2. こんにちは！
   ロージーです！
   

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3. Dec
   21 Dec
   22 Dec
   23
   今日はこの4日間で僕が学んだ DCI の話をします
   (クリスマスなんて知ったこっちゃねぇ)
   Dec
   24
   

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4. 1. What is DCI
   

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5. Data
   Context
   Interaction
   データ
   文脈
   挙動
   

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7. 全然わかんない！
   教えて！マスター＝センセイ！
   

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8. Ruby on Rails: The Bad Parts
   https://vimeo.com/50568777
   

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9. DCI and the application builds
   our mental models
   https://vimeo.com/51957143
   

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10. The Right Way to Code DCI in Ruby
    http://mikepackdev.com/blog_posts/24-the-right-way-to-code-dci-in-ruby
    

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11. and Github Repositories
    Alias DCI
    https://github.com/rebo/alias_dci
    DCI-Sample
    https://github.com/vsavkin/DCI-Sample
    DCI
    https://github.com/rubyworks/dci
    

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12. Data
    ex: User
    Behavior
    ex: Customer
    Story
    ex: Buy the Item
    Data Context Interaction
    

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13. 2. Where is Logics
    

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14. 『ユーザーが商品を買う』
    というロジックはどこにあるべきか論
    

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15. 例をご用意しました
    『ユーザーがアイテムを買う』
    User
    has_many :purchases
    Purchase
    belongs_to :user
    belongs_to :item
    Item
    has_many :purchases
    

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16. Case 1: Model
    class User
    def buy_item(item)
    self.purchases.create(item: item)
    end
    end
    https://gist.github.com/285ec33e6cfceb0ba0cf#file-case_1_model-rb
    

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17. Case 2: Controller
    class PurchasesController
    def create
    item = Item.find(params[:item_id])
    current_user.purchases.create(item: item)
    end
    end
    https://gist.github.com/285ec33e6cfceb0ba0cf#file-case_2_controller-rb
    

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18. Case 3: DCI
    class BuyItemContext
    def initialize(user, item)
    @user = user
    @item = item
    @user.extend(Customer)
    end
    def process
    @user.buy(item)
    end
    end
    module Customer
    def buy(item)
    self.purchases.create(item: item)
    end
    end
    https://gist.github.com/285ec33e6cfceb0ba0cf#file-case_3_dci-rb
    

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19. このサイズだと判断が難しいと思うけれど
    とりあえずコントローラにあるのはヤバそうな気配がする
    

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20. User#buy_item
    は、正しいのか
    

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21. Wikipedia 曰く
    Model View Controllerページ
    Model
    ͦͷΞϓϦέʔγϣϯ͕ѻ͏ྖҬͷσʔλͱखଓ͖ʢϏδωεϩδοΫ -
    γϣοϐϯάͷ߹ܭֹ΍ૹྉΛܭࢉ͢ΔͳͲʣΛදݱ͢ΔཁૉͰ͋Δɻ·
    ͨɺσʔλͷมߋΛviewʹ௨஌͢Δͷ΋modelͷ੹೚Ͱ͋Δʢmodelͷมߋ
    Λ௨஌͢ΔͷʹObserver ύλʔϯ͕༻͍ΒΕΔ͜ͱ΋͋Δʣɻ
    ଟ͘ͷΞϓϦέʔγϣϯͰ͸σʔλͷ֨ೲʹӬଓతͳهԱͷ࢓૊Έʢσʔ
    λϕʔεͳͲʣ͕࢖ΘΕ͍ͯΔɻMVCͷ֓೦Ͱ͸ɺσʔλͷʢUIҎ֎ͷʣ
    ೖग़ྗ͸औΓѻΘͳ͍ͷͰɺσʔλΞΫηε΋ຊདྷMVCͷ֓೦ͷൣᙝΛ௒
    ͑Δ΋ͷͰ͸͋Δ͕ɺ׶͍͑ͯ͑͹modelͷதʹӅṭ͞ΕΔͱߟ͑ΒΕΔɻ
    

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22. 正しいみたい！
    

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24. お疲れ様でした！
    まだ続きます
    

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25. 3. be Fat
    

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26. # Redmine - project management software
    # Copyright (C) 2006-2012 Jean-Philippe Lang
    #
    # This program is free software; you can redistribute it and/or
    # modify it under the terms of the GNU General Public License
    # as published by the Free Software Foundation; either version 2
    # of the License, or (at your option) any later version.
    #
    # This program is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    # GNU General Public License for more details.
    #
    # You should have received a copy of the GNU General Public License
    # along with this program; if not, write to the Free Software
    # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
    require "digest/sha1"
    class User < Principal
    include Redmine::SafeAttributes
    # Different ways of displaying/sorting users
    USER_FORMATS = {
    :firstname_lastname => {
    :string => '#{firstname} #{lastname}',
    :order => %w(firstname lastname id),
    :setting_order => 1
    },
    :firstname_lastinitial => {
    :string => '#{firstname} #{lastname.to_s.chars.first}.',
    :order => %w(firstname lastname id),
    :setting_order => 2
    },
    :firstname => {
    :string => '#{firstname}',
    :order => %w(firstname id),
    :setting_order => 3
    },
    :lastname_firstname => {
    :string => '#{lastname} #{firstname}',
    :order => %w(lastname firstname id),
    :setting_order => 4
    },
    :lastname_coma_firstname => {
    :string => '#{lastname}, #{firstname}',
    :order => %w(lastname firstname id),
    Redmine
    app/models/user.rb
    

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27. Token.delete_all ['user_id = ?', id]
    Watcher.delete_all ['user_id = ?', id]
    WikiContent.update_all ['author_id = ?', substitute.id], ['author_id = ?', id]
    WikiContent::Version.update_all ['author_id = ?', substitute.id], ['author_id = ?', id]
    end
    # Return password digest
    def self.hash_password(clear_password)
    Digest::SHA1.hexdigest(clear_password || "")
    end
    # Returns a 128bits random salt as a hex string (32 chars long)
    def self.generate_salt
    Redmine::Utils.random_hex(16)
    end
    end
    class AnonymousUser < User
    validate :validate_anonymous_uniqueness, :on => :create
    def validate_anonymous_uniqueness
    # There should be only one AnonymousUser in the database
    errors.add :base, 'An anonymous user already exists.' if AnonymousUser.exists?
    end
    def available_custom_fields
    []
    end
    # Overrides a few properties
    def logged?; false end
    def admin; false end
    def name(*args); I18n.t(:label_user_anonymous) end
    def mail; nil end
    def time_zone; nil end
    def rss_key; nil end
    def pref
    UserPreference.new(:user => self)
    end
    # Anonymous user can not be destroyed
    def destroy
    false
    end
    end
    Redmine
    app/models/user.rb
    706 lines
    

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28. Token.delete_all ['user_id = ?', id]
    Watcher.delete_all ['user_id = ?', id]
    WikiContent.update_all ['author_id = ?', substitute.id], ['author_id = ?', id]
    WikiContent::Version.update_all ['author_id = ?', substitute.id], ['author_id = ?', id]
    end
    # Return password digest
    def self.hash_password(clear_password)
    Digest::SHA1.hexdigest(clear_password || "")
    end
    # Returns a 128bits random salt as a hex string (32 chars long)
    def self.generate_salt
    Redmine::Utils.random_hex(16)
    end
    end
    class AnonymousUser < User
    validate :validate_anonymous_uniqueness, :on => :create
    def validate_anonymous_uniqueness
    # There should be only one AnonymousUser in the database
    errors.add :base, 'An anonymous user already exists.' if AnonymousUser.exists?
    end
    def available_custom_fields
    []
    end
    # Overrides a few properties
    def logged?; false end
    def admin; false end
    def name(*args); I18n.t(:label_user_anonymous) end
    def mail; nil end
    def time_zone; nil end
    def rss_key; nil end
    def pref
    UserPreference.new(:user => self)
    end
    # Anonymous user can not be destroyed
    def destroy
    false
    end
    end
    Redmine
    app/models/user.rb
    706 lines
    

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29. コードがすごく汚いとかではない
    (むしろいい方だと思う)
    

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30. じゃあなんで太るのか
    

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31. たいてい参照されるケースが多すぎる
    (User がやたら太るのはその理由)
    

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32. 90%のユーザーストーリーで必要のない
    振る舞いを抱え続けている
    

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33. 常に必要のない振る舞いは
    適宜与えてあげればいい
    

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34. それって、DCIでは？
    

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35. 4. Rails with DCI
    

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36. 現状の Rails で DCI をするには
    1. dci gem を頑張って使う(微妙)
    2. DCI-Sample みたいに自分で頑張る(辛い)
    3. user.extend(Customer) しまくる(妥当)
    4. ESM に gem 化をお願いする(どうなん)
    

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37. AOP
    じゃダメなの？
    

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38. 僕の理解が間違ってなければ AOP って
    #alias_method_chain
    なのでは
    

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39. もう自作したほうが早いのでは？
    

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40. Dicer
    https://github.com/rosylilly/dicer
    作ってみた
    

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41. WIP
    まだ実用に耐えない
    僕にお酒を飲ませると実装が進みます！
    

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42. 5. the Future
    

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43. Rails 4
    ちょっと見たけど、
    こういう問題への解決策の提示はなかった
    

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44. このままだと、主要モデルが太り続けるのは
    間違いない
    

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45. こんだけ喋ったけど
    僕もまだいい方法が思いつかない
    

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46. モデルダイエット勉強会誰かやりませんか＞＜
    (僕 DCI の勉強進めて DCI の話します)
    

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47. 応質
    答疑
    Question
    https://speakerdeck.com/rosylilly/dci-with-ruby
    

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