has_one with nested form

I have an Item model with has_one :geolocation association I need to create/update in one form

class Item < ActiveRecord::Base   has_one :geolocation, :dependent => :destroy   accepts_nested_attributes_for :geolocation, :reject_if => :all_blank, :allow_destroy => true   attr_accessible :geolocation_attributes .. end

class Geolocation < ActiveRecord::Base     belongs_to :item .. end

as stated in all docs in my Items table migration , I have a geolocation_id ( has_one association ) and in my Geolocations table , I have an item_id ( belongs_to association )

Creating the item in the controller   def new     @item = Item.new     @item.geolocation = Geolocation.new     respond_with(@item)   end   def create     @item = Item.new(params[:item])     if @item.save       redirect_to backoffice_item_path(@item), notice: t(:item_created)     else       render :new     end   end

with a nested form ... = simple_form_for @item, :url => backoffice_items_path, :html => {:class => 'form-vertical' } do |f|   ...    = f.fields_for :geolocation do |geolocation|

inserts correctly the item record and the geolocation record BUT in the item record, the geolocation_id is NOT set .. as if that the has_one association was not taken in account...

I'm surely missing something important , but I don't see what ... feedback and cue will be a big +++

thanks

[SOLVED] doesn't need this key ... has_one .. the key is in the target model 'item_id' in Geolocation