test.rb

require 'conderaction'

class Model
  def save
  end
end

class Changeset
  attr_reader :model, :context

  def initialize(klass, model, context)
    @klass = klass
    @model = model
    @context = OpenStruct.new(context)
    @context.api_role = :unknown if @context.api_role.blank?
    @context.persisted = false
  end

  def persist
    @klass.persist(model, context)
    @context.persisted = true
    self
  end

  def persisted?
    @context.persisted == true
  end

  def run(method_name, options = {})
    @klass.send(method_name)
    self
  end
end

class Action
  include DCI::Context

  def perform(*args)
    puts "   - Action::perform"
    data = changeset(*args)

    ActiveRecord::Base.transaction do
      change(data)

      unless data.persisted?
        fail "Did not create"
      end
    end

    data.model
  end

  def changeset(attributes, context = {})
    model = Model.new
    Changeset.new(self, model, context)
  end

  def change(data)
    data.persist
  end

  def persist(_model, _context)
    fail "You must override the persist method in the model action."
  end
end

class CreateAction < Action
  def perform(*_args)
    puts "  - CreateAction::perform"
    super
  end

  def persist(model, _context)
    puts "  - CreateAction::persist"
    model.save
  end
end

class ModelAction < CreateAction
  def perform(*_args)
    puts " - ModelAction::perform"
    super
  end

  def model_method
    puts "     - ModelAction::model_method"
  end

  def change(data)
    data
      .run(:model_method)
      .persist
  end
end

class UserModelAction < ModelAction
  def perform(*_args)
    puts "UserModelAction::perform"
    super
  end

  def user_method
    puts "    - UserModelAction::user_method"
  end

  def another_method
    puts "    - UserModelAction::another_method"
  end

  def change(data)
    data
      .run(:user_method)

    super
      .run(:another_method)
  end
end

UserModelAction.perform(1)