Ruby on rails 3 具有复杂模型的嵌套表单无法创建子项

我有一点复杂的模型关联：

class Company < ActiveRecord::Base
  has_many :roles, :dependent => :destroy
  has_many :users, :through => :roles
end

class Role < ActiveRecord::Base

  belongs_to :user
  belongs_to :company
  attr_accessor :roles_attributes
  attr_accessible :roles_attributes, :active, :company_id, :role 
  validates_presence_of :company_id, :role
  validates_uniqueness_of :user_id, :scope => :company_id, :message => "Users may only have one role per company."
end

class User < ActiveRecord::Base
  has_many :roles, :dependent => :destroy
  accepts_nested_attributes_for :roles, :allow_destroy => true 
  has_many :companies, :through => :roles
end

以及以下观点：

<%= simple_nested_form_for [:company, @user] do |f| %>
  <fieldset>
    <div class="form-horizontal">

    <%= f.input :email %>
    <%= f.input :name_first %>
    <%= f.input :name_last %>
    <%= f.input :title %>
    <%= f.input :phone %>
    <%= f.input :mobile %>

    <%= f.simple_fields_for :roles, @role do |role_form| %>
        <%= role_form.hidden_field :company_id %>
        <%= role_form.input :active %>
        <%= role_form.input :role, :collection => [ "Guest", "User", "Inspector", "Owner"] %></td>
    <% end %>
    <%= f.input :notes, :input_html => { :rows => 5, :cols => 70 } %>
    <div class="form-actions">
      <%= f.submit nil, :class => 'btn btn-primary' %>
      <%= link_to 'Cancel', company_users_path, :class => 'btn' %>
    </div>
  </fieldset>
<% end %>

我认为应该是：

"roles_attributes"=>[{"company_id"=>"2", "active"=>"1", "role"=>"Inspector"}]

---

我一定错过了什么明显的东西。

原来是

有安全的密码。我已删除密码字段，验证失败

"roles_attributes"=>{"0"=>{"company_id"=>"2", "active"=>"1", "role"=>"Inspector"}}

"roles_attributes"=>[{"company_id"=>"2", "active"=>"1", "role"=>"Inspector"}]