ruby on rails - Rails4 : Referencing associated model in fields_for partial -

i broke out form fields associated model partial. want reference associated model in partial i'm not sure how that. @position , @position_fields both nil. see render ..., object: @something not sure how reference current position model pass in.

apps/views/events/_form.html.erb

  <%= f.fields_for :positions |builder| %>     <%= render 'position_fields', f: builder %>   <% end %> 

apps/views/events/_position_fields.html.erb

fields <%= @position.name %> <%= f.text_field :name %> 

how reference associated model in fields_for partial?

in apps/views/events/_position_fields.html.erb, can following:

fields <%= f.object.name %> <%= f.text_field :name %> 

this because builder has reference each of position object , passing builder local position_fields partial name f.

reading through doc useful: http://apidock.com/rails/actionview/helpers/formhelper/fields_for.