Question

Here is code in customers controller:

  def edit
    @customer = Customer.find(params[:id])
    @return_to = params[:return_to]     
  end

  def update
    @customer = Customer.find(params[:id])

    if @customer.update_attributes(params[:customer], :as => :roles_new_update)

    redirect_to @return_to, :notice => 'Customer was updated successfaully!'
    else
      render 'edit', :notice => 'Customer was not updated!'
    end
  end

It is verified that there is value in @return_to in method edit. However there is an error saying: Cannot redirect to nil! for

   redirect_to @return_to, :notice => 'Customer was updated successfaully!'

in method update.

Any thoughts about the error? Thanks.

Answer 1

It’s because when you are on the edit action, that is one request to show the form. Then when you submit the form, that is a second request calling the update action. Any states set in an action are confined to that action alone. There’s a few ways to use data across multiple actions:

1. The database (So save it in a model)
2. The session hash
3. Pass it in the view to go into your form.

Because it’s a redirect/return to value, i would suggestion using a session variable such as:

session[:return_to] = params[:return_to]

In your edit action, then just refer to that value in your update:

session[:return_to]