club_registration.rb

class ClubRegistration
  
  def initialize(attributes = {})
    @attributes = attributes
  end
  
  def club
    @club ||= Club.new
  end
  
  def user
    @user ||= User.new
  end
  
  def role
    @role ||= Role.new
  end
  
  def first_member
    @first_member ||= Member.new
  end
  
  def create
    User.transaction {
      @club = Club.create(@attributes.fetch(:club))
      @user = User.create(@attributes.fetch(:user))
      @role = Role.create(user: @user, club: @club, role: Role::OWNER)
      @first_member = Member.create(
        @attributes
          .fetch(:user)
          .slice(:first_name, :last_name, :etc)
          .merge({lub: @club, user: @user)
      )
    }
  end
  
  def created?
    @club.id && @user.id && @role.id && @first_member.id
  end

end

# IN CONTROLLER
def new
  @club_registration = ClubRegistration.new
  # Render the form using the objects in @club_registration, e.g. @club_registration.user
end

def create
  @club_registration = ClubRegistration.new(params).create
  if @club_registration.create?
    redirect_to "some-main-dashboard"
  else
    # Use the objects in @club_registration to get errors for display in the view.
    # E.g. @club_registration.user.errors
    render :new
  end
end