Form for array element in partial

I'm making a project for which I have a class online_score which has as one of its attributes an array called url of online_score_url objects. What I did up to now is the following. views/online_score/new:

<div class="urlInput">    
<% f.fields_for :url do |b| %>
<%= render "online_score_url_fields", :f => b %>
<% end %>
<%= add_url_link "Add Another link", f %>
</div>

views/online_score/_online_score_url_fields:

<div class="inputset">
<%= f.label :url %>  <%= f.url_field :url, :value => "http://www.goo开发者_如何学Pythongle.be"%>
<%= f.label :description %>  <%= f.text_field :description %>
<%= link_to_remove_fields "remove", f %>
</div>

My problem is now that I want to be able to dynamically add inputs for online_score_urlobjects which I try to do with JQuery. I try to do this by rendering the partial like so: helpers/online_scores_helper.rb:

def add_url_link(name, form)
  link_to_function name do |page|    
  online_score_url = render(:partial => 'online_score_url_fields', :f => form )
  page << %{
    $('.links').append("#{ escape_javascript online_score_url }");
  }
  end
end

The problem is then that fseems to be undefined in the partial. I expect this has something to do with the line <% f.fields_for :url do |b| %> in my view which doesn't get executed via the dynamic adding. But I don't really know how to fix. I think I need an alternative for the form_formethod? How to do that?

I guess my main question is: how do I iterate over an array in a controlled way, and for every element create a set of input forms like in the partial AND be able to 'add' one or more dynamically?

Thanks for your time.

Try this one:

<%= render "online_score_url_fields", :locals => {:f => b} %>

this is beacuse :f is not a parameter for the render method. So you need to use :object, :collection or something locals with the syntax above.

The same here:

online_score_url = render(:partial => 'online_score_url_fields', :locals => {:f => form} )