FormObject

form_controller.rb

def create
  @form_object = UserRegistration::RegistrationForm.new(user_params, params[:notify])
  if @form_object.register
    ... #typically we flash and redirect here
  else
    render :new
  end
end

form_object.rb

module UserRegistration
  class RegistrationForm
    include ActiveModel::Model
    attr_accessor(
      :email,
      :name,
      :notify,
    )
  
  validates :email, presence: true
  validates :name, presence: true
    
    def initialize(email, name, notify)
      @email = email
      @name = name
      @notify = notify
    end
    
    def register
      initialize_user
      return false unless valid?
      result = user.save
      send_notifications
      result ? success : failure
    end

    private
    
    def initialize_user
      @user = User.new(email: email, name: name)
    end
    
    def send_notifications
      return unless notify
      NotifyService::Administrator.call(params)
      NotifyService::UserGroups.call(params)
    end
  end
end