業務場景

假定系統中存在 developer hacker designer startup 四種角色，且每種角色具獨立的權限需求。倘全部定義於ability.rb則未免過於臃腫而不可讀。

解決方案

基於角色維度進行ability.rb的切分如下：

# app/models/ability.rb
class Ability
  include CanCan::Ability

  def initialize(user)
    user ||= User.new
    if user.id.present?
      self.merge Abilities::LoginedUserAbility.new(user)
      self.merge Abilities.const_get("#{user.role}_ability".classify).new(user) if user.role.present?
    else
      self.merge Abilities::GuestAbility.new
    end
  end

end

# app/models/abilities/logined_user_ability.rb
module Abilities
  class LoginedUserAbility
    include CanCan::Ability
    def initialize(user)
     # ...
    end
  end
end

# app/models/abilities/developer_ability.rb
module Abilities
  class DeveloperAbility
    include CanCan::Ability
    def initialize(user)
     # ...
    end
  end
end

其餘角色同上

原文首發於我的博客 https://blog.boris.tech/posts/fu-za-luo-ji-xia-jie-ou-cancancan-de-ability-mo-xing