ActAsPermissionControllable

Control user / admin permissions with cancancan.

Easily integrate cancancan into your application with permission control of every controller action.

Installation

Add this line to your application's Gemfile:

gem 'act_as_permission_controllable'

And then execute:

$ bundle

Or install it yourself as:

$ gem install act_as_permission_controllable

Migration

Add a permissions JSONB field to your model:

rails g migration AddPermissionsToAdmins permissions:jsonb

Add default: {}, nil: false:

class AddPermissionsToAdmins < ActiveRecord::Migration[5.1]
  def change
    add_column :admins, :permissions, :jsonb, default: {}, nil: false
  end
end

Model

Add act_as_permission_controllable to your model:

class Admin < ApplicationRecord
  act_as_permission_controllable # methods added: ban, permit, assign_permissions, can?
end

Create app/models/ability.rb:

class Ability
  include ActAsPermissionControllable::Ability
end

Controller

Add grant_permission to your base controller. Controllers inherited from it will need authorization. You can rescue from CanCan::AccessDenied error to show permission error message. You also need to define current_ability for cancancan to work.

class Admin::BaseController < ApplicationController

  # ... other code ...

  grant_permission

  rescue_from CanCan::AccessDenied do |exception|
    respond_to do |format|
      format.json {
        render json: { message: exception.message }, status: 403
      }
      format.html {
        render 'act_as_permission_controllable/forbidden', layout: 'admin', status: 403, locals: { exception: exception }
      }
    end
  end

  private

    def current_ability
      @current_ability ||= Ability.new(current_admin)
    end

  # ... other code ...
end

If you don't want a controller to check user permission, use skip_grant_permission.

class Admin::HomeController < Admin::BaseController
  skip_grant_permission
end

If your controller has different index page:

class Admin::AdminsController < Admin::BaseController
  grant_permission index: :welcome

  def welcome
  end
end

To edit permissions on the web page, add actions to your routes:

resources :admins do
  member do
    match :permissions, via: [ :get, :post ]
  end
end

And in your controller:

class Admin::AdminsController < Admin::BaseController
  # ... other code ...

  def permissions
    if request.post?
      @admin.assign_permissions(params.fetch(:actions, []))
      if @admin.save
        flash[:notice] = 'OK!'
      else
        flash[:error] = 'ERROR!'
      end
      redirect_to params[:referer].presence || permissions_admin_admin_path(@admin)
      return
    end

    render 'act_as_permission_controllable/permissions'
  end

  # ... other code ...
end

View

You can use controllable_nav_items to list permitted pages for current user:

<ul class="nav navbar-nav">
  <% controllable_nav_items do |item| %>
    <%= content_tag :li, class: (name = item.controller_name) == controller.controller_name ? 'active' : nil do %>
      <%= link_to item.i18n_name, (url_for(controller: name, action: item.index) rescue nil) %>
    <% end %>
  <% end %>
</ul>

I18n

You can customize the names of each controller action and the order of each controller:

# config/locales/aapc.en.yml
en:
  act_as_permission_controllable:
    order:
      - Admin::OrdersController
      - Admin::SettingsController
      - Admin::AdminsController
    controllers:
      Admin::AdminsController:   'Admins'
      Admin::OrdersController:   'Orders'
      Admin::SettingsController: 'Settings'
    actions:
      Admin::AdminsController:
        permissions: 'View and Set Permissions'
      Admin::OrdersController:
        export: 'Export Orders'

Methods

ban(subject, *actions) and permit(subject, *actions)

# permit multiple actions of a controller
Admin.find(1).permit(:user, :create, :update, :destroy).save

# permit all actions in user controller
Admin.find(1).permit(:user, :all).save

# ban all except some permissions
Admin.find(1).ban(:all).permit(:settings, :update).save

# permit all except some permissions
Admin.find(1).permit(:all).ban(:admin, :permissions).save

# you can use controller class name as subject
Admin.find(1).ban(:all).permit('Admin::SettingsController', :update).save

can?(action, subject)

if current_admin.can?(:destroy, :user)
  # admin can destroy user
end

Example

You can run the app in test/dummy directory and visit http://admin.localhost.com:3000.

Contributing

You can open issues or pull requests on GitHub.

License

The gem is available as open source under the terms of the MIT License.