title: ActiveMerchant purchase function rails 3.2.5 mass-assign
body: <p>I am using Rails 3.2.5. Following Ryan Bates tutorial. </p>
  
  <p><a href="http://railscasts.com/episodes/145-integrating-active-merchant" rel="nofollow">http://railscasts.com/episodes/145-integrating-active-merchant</a>. My order.rb has this function </p>
  
  <pre><code>  def purchase
      response = GATEWAY.purchase(price_in_cents, credit_card, purchase_options)
      transactions.create!(:action =&gt; "purchase", :amount =&gt; price_in_cents, :response =&gt; response)
      cart.update_attribute(:purchased_at, Time.now) if response.success?
      response.success?
    end
  </code></pre>
  
  <p>Since rails 3.2.5 uses MassAssignmentSecurity.I get the following error.</p>
  
  <pre><code>Can't mass-assign protected attributes: action, amount, response
  </code></pre>
  
  <p>I have tried adding them to the attr_accessible list but no luck. How do i add them to the list or at-least override them?</p>