Rails 2.3中带有集合的嵌套模型表单

如何在Rails 2.3中实现这一点?

class Magazine < ActiveRecord::Base
  has_many :magazinepages
end

class Magazinepage < ActiveRecord::Base
  belongs_to :magazine
end

然后在控制器中:

def new
  @magazine = Magazine.new
  @magazinepages = @magazine.magazinepages.build
end

<% form_for(@magazine) do |f| %>
  <%= error_messages_for :magazine %>
  <%= error_messages_for :magazinepages %>
  <fieldset>
    <legend><%= t('new_magazine') %></legend>
      <p>
        <%= f.label :title %>
        <%= f.text_field :title %>
      </p>
      <fieldset>
        <legend><%= t('new_magazine_pages') %>
          <% f.fields_for :magazinepages do |p| %>
            <p>
              <%= p.label :name %>
              <%= p.text_field :name %>
            </p>
            <p>
              <%= p.file_field :filepath %>
            </p>
          <% end %>
      </fieldset>
    <p>
      <%= f.submit :save %>
    </p>
  </fieldset>
<% end %>

问题是,若我想提交一个杂志集,activerecord投诉,因为它应该是一个模型,而不是一个数组。

def create
  @magazine = Magazine.new params[:magazine]
  @magazine.save ? redirect_to(@magazine) : render(:action => 'new')
end