Light::Services

Implementation of Service Object Pattern for Ruby/Rails. Compatible with Rails 5.1 and 5.0, 4.2, 4.1, 4.0.

Service Object Pattern – What is it? Check it here:

Installation

Add this line to your application's Gemfile:

gem 'light-services', '~> 0.6'

And then execute:

$ bundle

Or install it yourself as:

$ gem install light-service

Usage

Examples of usage:

Change state of the record:

class Painting::Publish < ApplicationService
  # Parameters
  param :painting, type: Painting
  param :user,     type: User

  # Callbacks
  before :authorize
  after  :send_email_notification

  def run
    painting.publish!
  end

  private

  def authorize
    pundit_authorize!(painting, user, :publish?)
  end

  def send_email_notification
    PaintingMailer.publish_email(painting).deliver_now
  end
end

Create a new record:

class Owner::Create < ApplicationService
  # Parameters
  param :params, type: ActionController::Parameters
  param :user,   type: User

  # Outputs
  output :owner

  # Callbacks
  before :assign_attributes
  before :authorize
  before :validate

  def run
    owner.save!
  end

  private

  def assign_attributes
    self.owner = Owner.new(owner_params)
  end

  def authorize
    pundit_authorize!(owner, user, :create?)
  end

  def validate
    return if owner.valid?
    errors.from_record(owner)
  end

  def owner_params
    params
      .require(:owner)
      .permit(:name)
  end
end

Integration with Pundit:

class ApplicationService < Light::Services::Base
  def pundit_authorize!(record, user, action = nil)
    action = convert_action(action, :show?)
    policy = Pundit.policy!(user, record)

    return true if policy.public_send(action)

    Rails.logger.info "Pundit: not allowed to #{action} this #{record.inspect}"
    raise Pundit::NotAuthorizedError, query: action, policy: policy, record: record
  end

  def pundit_scope!(scope, user, action = nil)
    action = convert_action(action, :index?)
    pundit_authorize!(scope, user, action)

    Pundit.policy_scope!(user, scope)
  end

  private

  def convert_action(action, default)
    action = action.to_s

    return default if action.blank?
    return action if action.ends_with?('?')

    action + '?'
  end
end

Development

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 tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/light-service. 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.