action_base.rb

class ActionBase
  def self.call(*params)
    new(*params).call
  end
  
  def self.on(event, *methods)
    methods.each { |m| __on_listeners[event.to_sym] << m.to_sym }
  end

  def self.__on_listeners
    @__on_listeners ||= Hash.new { |hash, key| hash[key] = [] }
  end
  
  def self.call_event(options={})
    options.reverse_merge!(
      on: :success,
      actor: :actor,
      resource: :resource,
      target: :target,
      context: :context,
      klass: "#{name}Event"
    )
    
    @__call_events ||= 0
    
    define_method("__call_event_#{@__call_events}") do
      options[:klass].safe_constantize.call(options.slice(:actor, :resource, :target, :context))
    end
    
    on options[:on], "__call_event_#{@__call_events}"
  end
  
  private
  
  def publish(event)
    self.class.__on_listeners[event.to_sym].each { |m| send(m) }
  end
  
  def create(parent, attributes, ivar=nil)
    parent.create(attributes).tap do |object|
      instance_variable_set("@#{ivar}", object) if ivar.present?

      if object.persisted?
        yield object if block_given?
        publish :success
      else
        publish :failure
      end
    end
  end

  def update(object, attributes)
    object.tap do
      if object.update(attributes)
        yield object if block_given?
        publish :success
      else
        publish :failure
      end
    end
  end

  def destroy(object)
    object.tap do
      if object.destroy
        yield object if block_given?
        publish :success
      else
        publish :failure
      end
    end
  end
end

example.rb

class Example < ActionBase
  call_event on: :success, actor: :current_user, resource: :user, target: -> { @user.parent }, context: nil, klass: 'ExampleEvent'
  on :success, :print_info
  
  def initialize(user, attributes, current_user)
    @user = user
    @attributes = attributes
    @current_user = current_user
  end
  
  def call
    update(@user, @attributes)
  end
  
  private
  
  def print_info
    puts "Success"
  end
end