Rails 将错误添加到：base 未按预期工作

Question

我有一个双重嵌套形式：

<%= simple_form_for @item, html: { class: "create-item-form" } do |item_builder| %>
  <div class="well">
  <%= item_builder.input :name, required: false, error: false, label: "item name" %>
  <%= item_builder.input :description, as: :text, required: false, error: false, label: "How do users earn this item?" %>
  <%= item_builder.input :tag_list, required: false, label: "Tags (these will help users find your item)" %>

  <%= item_builder.simple_fields_for :user_items do |user_item_builder| %>
    <%= user_item_builder.input :foo, as: :hidden, input_html: { value: "bar" } %>

    <%= user_item_builder.simple_fields_for :user_item_images do |user_item_images_builder| %>
      <%= user_item_images_builder.input :foo, as: :hidden, input_html: { value: "bar" } %>
      <%= user_item_images_builder.input :picture, as: :file, required: false,
                error: false, label: "Pictures of you earning this item",
                input_html: { multiple: true,
                              name: "item[user_items_attributes][0][user_item_images_attributes][][picture]" } %>
      <% end %>
  <% end %>
  </div>
  <div class="clearfix">
    <%= item_builder.submit 'Submit new item request', class: "btn btn-primary pull-right inherit-width" %>
  </div>
<% end %>

当用户没有为user_item_image 上传文件时，我需要显示一条错误消息。我写了一个自定义验证：

user_item_image.rb

class UserItemImage < ActiveRecord::Base

  include PicturesHelper

  attr_accessor :foo

  mount_uploader :picture, PictureUploader
  belongs_to :user_item
  validate :picture_size
  validate :has_picture

  private

  def has_picture
    errors.add(:base, 'You must include at least one picture.') if picture.blank?
  end
end

但我收到错误消息：

用户项目用户项目图片库您必须至少包含一张图片。

如何重写验证，使其不显示属性而只显示消息。

Answer 1

为什么不使用

validates :picture, presence: true

在您的 useritem 模型上