Rails nested form using Formtastic - can't get association to update

Question

In a rails application I want to update a nested attribute from a user's edit page. In the console I can do this:

foo = User.first.memberships.first
foo.organization_id = 10
foo.save

This will update the organization ID. I want to do this in a form using formtastic. First, my User model includes:

accepts_nested_attributes_for :memberships

The form looks like this:

<%= semantic_form_for [:admin, @resource], role: "form" do |f| %>

<div class="form-group">
  <%= f.input :email, label: "Email" %>
  <%= f.input :avatar, as: :file, name: "Avatar" %>
  <%= f.input :first_name, label: "First Name" %>
  <%= f.input :last_name, label: "Last Name" %>
  <%= f.input :admin, as: :boolean, label: "Admin" %>
  <%= f.input :password, as: :password, label: "Password" %>
  <%= f.input :password_confirmation, as: :password, label: "Password Confirmation" %>
</div>

<div class="form-group">  
  <%= f.inputs :for => :memberships do |input| %>
    <%= f.input :organizations, :as => :radio, :collection => memberships_for_user %>
  <% end %>
</div>

<div class="small-spacer"></div>
<%= f.submit "Save User", class: "btn primary" %>
<% end %>

The helper method for the collection is this:

def memberships_for_user
  Organization.all
              .sort_by { |o| o.name }
              .map     { |o| [o.name, o.id] }
end

The ensuing html for the nested attributes look like this:

<li class="choice">
  <label for="user_organization_ids_10">
    <input id="user_organization_ids_10" name="user[organization_ids]" type="radio" value="10" />Beer-Davis
  </label>
</li>

How can i fix this so that this form updates the organizaiton_id on the Memberships join model?

Answer 1

Try

<%= f.inputs :for => :memberships do |mf| %>
  <%= mf.input :organizations, :as => :radio, :collection => memberships_for_user %>
<% end %>