interning empty string error

Question

Currently, in my request model I have:

belongs_to :requestor, :class_name => 'User'

So the requestor is the current_user.

Problem is when the current_user clicks the create button to submit a form for a request, all of the attributes get updated to the database that are in the form.
But since requestor_id is not a value to fill out in the form, that brings back a value of null in the database when the new request record is created.
What I want is an integer (which equates to the primary key of the Users table) updated in the requestor_id column in the request table when the user clicks the create button.
So I thought that maybe adding a requestor_id as a symbol in the params for the create action would solve that:

def create_common
  @a = Request.new
    b = @a.requestor_id
  @resource = yield params[:contact + "#{b}".to_sym]
  self.resource = @resource

But instead it returns the following error:

interning empty string

Thanks for any suggestions.

Answer 1

I kept getting this error. I traced it to very simple code and reproduced in the console with this:

ruby-1.8.7-p174 :084 > a = 'fred'
 => "fred" 
ruby-1.8.7-p174 :085 > a.to_sym
 => :fred 
ruby-1.8.7-p174 :086 > a = ''
 => "" 
ruby-1.8.7-p174 :087 > a.to_sym
ArgumentError: interning empty string
    from (irb):87:in `to_sym'
    from (irb):87

Answer 2

Can you not just pass the Request the current_user when you create it?

@req = Request.new(:requestor => current_user)

I am not quite sure what the yield params statement is meant to be doing,