SimplePolicy

Policy system for Ruby with awesome features!

Helps you to define policy in a simple way. Define your policies in classses, it means you can separate them from models and reuse them.

Add this line to your application's Gemfile:

gem 'simple_policy'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install simple_policy

Policies are defined as plain Ruby classes. For rails usage you can put definitions inside app/policies folder.

When we want define basic policy class, simply do that:

class UserEndOfSubscriptionPolicy < SimplePolicy::Entity
  object_alias :user

  def call
    block_passed? && correct_action? && end_of_subscription?
  end

  def block_passed?
    return true unless block

    instance_eval(&block)
  end

  def correct_action?
    options[:action] == 'games/play'
  end

  def end_of_subscription?
    user.end_of_subscription_at < Time.now
  end
end

After that we can use our policy for one object:

User = Struct.new(:end_of_subscription_at, :check_subscription)

user = User.new(Time.now - (60 * 60 * 24), false)

UserEndOfSubscriptionPolicy.applies_to?(user, action: 'games/play')
#=> true

UserEndOfSubscriptionPolicy.applies_to?(user, action: 'games/play') { user.check_subscription }
#=> false

Or for collection:

User = Struct.new(:end_of_subscription_at, :check_subscription)

users = Array.new(5) { |i| User.new(Time.now - (60 * 60 * 24 * (i - 2)), false) }

UserEndOfSubscriptionPolicy.applies_to_all?(users, action: 'games/play')
#=> false

UserEndOfSubscriptionPolicy.applies_to_all?(users, action: 'games/play') { user.check_subscription }
#=> false

UserEndOfSubscriptionPolicy.applies_to_any?(users, action: 'games/play')
#=> true

UserEndOfSubscriptionPolicy.applies_to_any?(users, action: 'games/play') { user.check_subscription }
#=> false

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. 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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/norbertmaleckii/simple-policy-rb. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

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

Everyone interacting in the SimplePolicy project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.