View with custom mime-type doesn't receive instance variable

In a rails3 app (3.0.5), I've declared the following mime-type (in config/initializers/mime_types.rb):

Mime::Type.register_alias "text/html", :print

In orders_controller.rb, I've the following action:

respond_to :html

def show
  @order = Order.find(params[:id])
  respond_with @order do |format|
    format.print
  end
end

Then I currently have 2 identical views co开发者_如何学JAVArresponding to the html and print format:

show.html.haml:

= @order.name

show.print.haml:

= @order.name

Everything works as expected with the 'html' path, ie /orders/2 renders the shows the name of the order with id == 2, but if I try /orders/2.print, I get a

undefined method 'user' for nil:NilClass

as if the @order instance variable isn't passed to the 'print' view. What am I missing? Any ideas? It should be trivial, but I'm stuck on this since a few hours!

Ok, sorry for that, I had a before_filter method that was hiccuping on the custom mime-type. Everything is working now (I'm still learning to thoroughly read the log in case of errors).