I am implementing a simple RoR webpage that collect emails from visitors and store them as objects.

I'm using it as a mini-project to try RoR and BDD. I can think of 3 features for Cucumber: 1. User submits a valid email address 2. User submits an existing email address 3. User submits an invalid email

My question is, for scenarios 2 and 3, is it better to handle this via the controller? or as methods in a class? Perhaps something that throws errors if an instance is instantiated in sceanrio 2 or 3?

Implementation is below, love to hear some code reviews in addition to answers to questions above. Thanks!

MODEL:

class Contact < ActiveRecord::Base
    attr_accessor :email
end

VIEW:

<h1>Welcome To My Experiment</h1>
<p>Find me in app/views/welcome/index.html.erb</p>

<%= flash[:notice] %>

<% form_for @contact, :url => {:action => "index"} do |f| %>
<%= f.label :email %><br />
<%= f.text_field :email %>
<%= submit_tag 'Submit' %>
<% end %>

CONTROLLER:

class WelcomeController < ApplicationController
  def index
    @contact = Contact.new
    unless params[:contact].nil?
      @contact = Contact.create!(params[:contact])
      flash[:notice] = "Thank you for your interest, please check your mailbox for confirmation"
    end  
  end
end