Rails "please wait" page

Question

I have a rails app that imports all your Facebook contacts. This takes some time. I would like to be able to show a "please wait" page while the importing keeps happening in the back.

It seems that I cannot put render and redirect_to on the same action in the controller. How can I do this?

if @not_first_time
    Authentication.delay.update_contact_list(current_user)
else
    render 'some page telling the user to wait'
    Authentication.import_contact_list(current_user)
end
redirect_to :root_path, :notice => 'Succesfully logged in'

If it is the users first time in the site, i want to render a "please wait page", start importing, and once its done redirect to the root path, where a lot of processing with this data happens

If it is not the first time, then put the contact update in the background (using the delayed_jobs gem) and go straight to the home page

I'm using the fb_graph gem to import the contacts. Here's the method

def self.import_contact_list(user)
  user.facebook.friends.each do |contact|
  contact_hash = { 'provider' => 'facebook', 'uid' => contact.identifier, 'name' => contact.name, 'image' => contact.picture(size='large') }
  unless new_contact = Authentication.find_from_hash(contact_hash)
    ##create the new contact
    new_contact = Authentication.create_contact_from_hash(contact_hash)
  end
  unless relationship = Relationship.find_from_hash(user, new_contact)
    #create the relationship if it is inexistent
    relationship = Relationship.create_from_hash(user, new_contact)
  end
end

end

Edit

I added the solution suggested below, it works!

Here's is my 'wait while we import contacts' view from the action "wait"

<script>
jQuery(document).ready(function() {
  $.get( "/import_contacts", function(data) {
    window.location.replace("/")
  });
});
</script>

<% title 'importing your contacts' %>

<h1>Please wait while we import your contacts</h1>
<%= image_tag('images/saving.gif') %>

Thanks!

Answer 1

A single request receives a single response - you can't render content and redirect.

If I were you I would always do the lengthy process in delayed job - tying up passenger/unicorn instances is never a great idea. Render a 'please wait page' that refreshes periodically to check whether the delayed job has completed (if you stash the id of the delayed job you can test whether it is still in the db. When te job completes it will be deleted). When the job is complete, redirect to the results page. You could also do the periodic checking bit via ajax.