title: How to return success for .save() even if record also exists? -- Rails 3.1
body: <p>I'm trying to modify the following code to make it return the flash notice and success if the <code>email</code> exists.</p>
  
  <pre><code>class SubscribersController &lt; ApplicationController
    respond_to :json
  
    def create
      @subscriber = Subscriber.new(:first_name     =&gt; params[:first_name],
                                   :last_name      =&gt; params[:last_name],
                                   :email          =&gt; params[:email],
                                   :ip_address     =&gt; request.remote_ip,
                                   :referring_page =&gt; request.referer )
      if @subscriber.save
        flash[:notice] = "You've been subscribed!"
      end
  
      respond_with(@subscriber)
    end
  
  end
  </code></pre>
  
  <p><strong>How could I check if the email address exists already and return success with the flash message?</strong></p>
  
  <p><strong>I don't want to throw an error if the email already exists (which the model checks for) -- I want to still say you've been subscribed.</strong></p>
  
  <p>I've tried checking with <code>.present?</code> but it throws an error:</p>
  
  <pre><code>&lt;h1&gt;
    NoMethodError
      in SubscribersController#create
  &lt;/h1&gt;
  &lt;pre&gt;undefined method `model_name' for ActiveRecord::Relation:Class&lt;/pre&gt;
  </code></pre>