Question

At each step in my checkout process, an order is updated via a PUT request. However, one of the states has a form that submits to a third party which redirects back to my site, calling the update method with GET (no control over this).

Why does my respond_with code appear to be totally ignored and I get a Missing Template checkout/update error? It should be hitting #edit.

CheckoutController.rb

before_filter :load_order

def update
  if @order.update_attributes(params[:order])
    @order.next
  end
  respond_with(@order, :location => checkout_state_url(@order.state))
end

routes.rb

match '/checkout/update/:state' => 'checkout#update', :as => :update_checkout
match '/checkout/:state' => 'checkout#edit', :as => :checkout_state
match '/checkout' => 'checkout#edit', :state => 'client_details', :as => :checkout

Answer 1

It looks like respond_with does different things depending upon the HTTP verb and whether the resource has errors. See here and here.

The following code worked for me:

def update
    if @order.update_attributes(params[:order]) && @order.next
        respond_with(@order) { |format| format.html { redirect_to checkout_state_url(@order.state) } }
    else
        respond_with(@order) { |format| format.html { render :edit } }
    end
end