Question

I am trying to create a nested form rails in which will create two model at the same time. The model are has follow:

Model/Events

#Data
  attr_accessible :customer_id, :description, :locations_attributes
#Relationship
  has_many :locations
  accepts_nested_attributes_for :locations, :allow_destroy => true

Model/Locations

#Data
  attr_accessible :address, :customer_id, :event_id, :latitude, :longitude
#Relationship
  belongs_to :customer
  belongs_to :event

The view his like this

<%= form_for(@event) do |f| %>
  <div class="field">
    <%= f.label :title %><br />
    <%= f.text_field :title %>
  </div>
  <%= f.fields_for :locations do |e| %>
    <%= e.hidden_field :longitude %>
    <%= e.hidden_field :latitude %>
  <% end %>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

The controller looks like this

  def new
    @event = Event.new
    @location = Location.new
    ...
  def create
    @event = current_customer.events.build(params[:event])
    @event.locations.build(params[:locations])
    respond_to do |format|
    ...

The issues is that when I create the events, the form is generated, it create the events and create a locations and associated to the events, but my longitude and latitude field are empty. I must note they are float type, but i don’t understand why it shouldn’t work

Update: I notice for me to be able to access the field_for i must change the field_for to single

 <%= f.fields_for :location do |e| %>

But then when doing this i get the following error when trying to create the event

Can't mass-assign protected attributes: location

and the params is has follow

 "location"=>{"longitude"=>"-80.9460917",
 "latitude"=>"46.4350391"}

This is my javascript

function getLocation()
{
    if (navigator.geolocation)
    {
        navigator.geolocation.getCurrentPosition(showPosition);
    }
}
    function showPosition(position)
    {
        document.getElementById('event_location_latitude').value=position.coords.latitude;
        document.getElementById('event_location_longitude').value=position.coords.longitude;
    }

I admits its ugly but it does the jobs from application.js I called it with a function in the form

<script type="text/javascript">
   getLocation();
  </script>

Which is just before <% end %> of the form

Answer 1

check this out.

http://railscasts.com/episodes/196-nested-model-form-revised

if you have questions after viewing it. let me know

In your hidden field code you need to set a value. For example.

<%= f.hidden_field :song_id, value: params[:id] %>
<%= f.hidden_field :paid_price,  value: @song.price %>