letz / atomic-service

A base class to build DRY service objects in Ruby

atomic-service

AtomicService, a base class to build DRY service objects for Rails apps that take advantage of ActiveModel validations.

A service object:

class CreatePostService < AtomicService
  attr_accessor :title, :body, :author
  attr_reader :post

  validates :title, :body, presence: true 
  validates_acceptance_of :post_slots_available, if: :before_execution?

  def execute
    within_transaction do 
      create_post

      after_commit { @post.send_email_notification_to_subscribers }
    end
  end

  private 

  def create_post
    @post = Post.create(defined_attributes(:title, :body, :author))
    valid?(@post)
  end 

  def post_slots_available
    author.posts.count <= 10
  end
end

Executing a service object:

Option 1: Instantiating and calling the service object

service = CreatePostService.new(title: 'Foo', body: 'Bar', author: current_user)
if service.call
  @post = service.post
else
  error_message = "Error creating post: #{service.formatted_errors}"
end

Option 2: Instantiating and calling the service object with a bang

service = CreatePostService.new(title: 'Foo', body: 'Bar', author: current_user)
service.call! # An exception will be raised if the service does not execute correctly.

Option 3: Calling directly via class method

data = CreatePostService.call(title: 'Foo', body: 'Bar', author: current_user)

if !data.successful?
  puts data.formatted_errors
end