DeviseCan
Why devise_can gem?
By device_can gem you'll get functionality of devise,cancancan and user_role_association that make your development easy.
Installation
Add this line to your application's Gemfile:
gem 'devise_can'And then execute:
$ bundle
Or install it yourself as:
$ gem install devise_can
Usage
You need to follow all given steps i.e.
Generate devise component
rails generate devise:install
Now add require 'devise' to your config/application.rb
rails generate devise user
This will generate devise model with name User, you can either generate views and controller as well by following command:
rails generate devise:views
rails generate devise:controllers users
Generate association component
rails generate association user_role
It'll generate two models with name Role and UserRole
class Role < ActiveRecord::Base
has_many :user_roles
has_many :users,through: :user_roles
validates :name,presence: true
end
class UserRole < ActiveRecord::Base
belongs_to :user
belongs_to :role
validates :user,presence: true
validates :role,presence: true
validates_uniqueness_of :user_id, scope: :role_id
end
Add association into model User i.e.
has_many :user_roles
has_many :roles,through: :user_roles
Generate cancan component
rails generate cancan:ability
It'll create a model with name Ability
Generate permission component
rails generate permission module
It'll generate three models with name ModuleAction , ModuleGroup and ModulePermission.Each model looks like:
class ModuleAction < ApplicationRecord
has_many :module_permissions
has_many :module_groups,through: :module_permissions
end
This model will contain all module name like `User` or `Role` etc..
class ModuleGroup < ApplicationRecord
has_many :module_permissions
has_many :module_actions,through: :module_permissions
end
This model will contain all actions for controller like `create/new/index/update/show` etc..
class ModulePermission < ApplicationRecord
belongs_to :module_group
belongs_to :module_action
belongs_to :role
end
This model will contain association between `module_group` , `module_action` and `role`.
Now your ability.rb file should look like:
class Ability
include CanCan::Ability
def initialize(user)
# Define abilities for the passed in user here. For example:
#
# user ||= User.new # guest user (not logged in)
# if user.admin?
# can :manage, :all
# else
# can :read, :all
# end
#
# The first argument to `can` is the action you are giving the user
# permission to do.
# If you pass :manage it will apply to every action. Other common actions
# here are :read, :create, :update and :destroy.
#
# The second argument is the resource the user can perform the action on.
# If you pass :all it will apply to every resource. Otherwise pass a Ruby
# class of the resource.
#
# The third argument is an optional hash of conditions to further filter the
# objects.
# For example, here the user can only update published articles.
#
# can :update, Article, :published => true
#
# See the wiki for details:
# https://github.com/CanCanCommunity/cancancan/wiki/Defining-Abilities
if user.roles.pluck(:name).include?('superadmin')
can :manage, :all
else
user.roles.map{|role| role.module_permissions}.each do |permissions|
permissions.each do |permission|
can permission.module_action.name.to_sym,permission.module_group.name.constantize
end
end
end
end
end
Here superadmin is a role with all permissions on each module.
Run migrations
Now you need to run migrations for schema update
rails db:migrate
Other stuffs
Add following lines into your application controller:
rescue_from CanCan::AccessDenied do |exception|
flash[:warning] = exception.message
redirect_to root_path
end
It'll check ability.rb on each action and reirect to root_path if found unpermitted action.
Development
After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/devise_can. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.