现在我有@H_301_3@

f.collection_select(:category_id,@categories,:id,:name,{:prompt => 'Please select a category'})

它产生@H_301_3@

<select id="product_category_id" name="product[category_id]">
  <option value="">Please select a category</option>
  <option value="7">category one</option>
  <option value="8">category 2</option>
</select>

我想要的是@H_301_3@

<select id="product_category_id" name="product[category_id]">
  <option value="">Please select a category</option>
  <option value="7">category one</option>
  <option value="8">category 2</option>
  <option value="new">..or create a new one</option>
</select>

这是可能的还是应该循环遍历集合并手动生成选项？@H_301_3@