title: Rails 3.2 - How to merge params without displaying everything in the URL?
body: <p>In my app I have a <code>/thanks</code> page that users were originally redirected to when completing a certain action. Now I want to redirect them to this page after multiple kinds of events and render different partials based on what the event was. So I added this to the <code>/thanks</code> page:</p>
  
  <pre><code>- case @event
    - when "reservation"
      = render 'thanks_job_created'
    - when "charge"
      = render 'thanks_job_charged'
  </code></pre>
  
  <p>Then, in the the <code>JobsController#create</code> action, I changed <code>redirect_to thanks_jobs_path</code> to this:</p>
  
  <pre><code>redirect_to thanks_jobs_path(params.merge(event: "reservation"))
  </code></pre>
  
  <p>...and added <code>@event = params[:event]</code> to <code>JobsController#thanks</code>. </p>
  
  <p>The behavior works as intended, but I've found that using <code>params.merge</code> this way now displays every paramter in the URL, including authenticity token of the <code>#create</code> form, all of the Job attributes, etc. Before the URL looked correct (<code>/jobs/thanks</code>) because the only params were <code>action</code> and <code>controller</code> which are already indicated in the URL.</p>
  
  <p>Is there a way for me to use <code>params.merge</code> without displaying all of that info in the URL? </p>