ruby-on-rails - rails : How to install CanCan?

Question

我已经安装了 CanCan 并将行 gem 'cancan' 添加到 Gemfile。运行 bundle。

我用代码创建了 app/models/ability.rb:

class Ability
  include CanCan::Ability
  def initialize(user)
    user ||= User.new # guest user (not logged in)
    if user.admin?
      can :manage, :all
    end
  end
end

ActiveAdmin 和 Devise 已安装并插入。

我添加了 if cannot? 到 app/admin/codes.rb:

ActiveAdmin.register Code do
  if cannot? :manage, Code
    flash[:notice] = "Access denied"
    redirect_to '/'
  end

  index do
    column :id
    column :title
    column :author
    column :created_at
    column :updated_at
    column :language
    default_actions
  end
end

rails 无法启动服务器或打开 rails 控制台:

app/admin/codes.rb:2:in `block in <top (required)>': undefined method `cannot?'
for #<ActiveAdmin::ResourceDSL:0x4ae7fe8> (NoMethodError)

我该如何解决？

Answer 1

cancan 方法被添加到所有 Controller 和模型，而不是其他任何东西，因此您需要在 ActiveAdmin 类中手动包含 cancan 方法。考虑遵循此处的模式:

https://github.com/ryanb/cancan/blob/master/lib/cancan/controller_additions.rb

使用类似include CanCan::ControllerAdditions