Ruby on Rails的 - 如何委派从嵌套模型错误信息(Ruby on Rails - How

class User
  include Mongoid::Document

  has_many :images
  accepts_nested_attributes_for :image
end


class Image
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Paperclip

  has_mongoid_attached_file :uploaded_image,
    :path => ":rails_root/public/uploads/:class/:id/:basename.:extension",
    :url => "public/uploads/"
    validates_attachment_content_type :uploaded_file, :content_type => "application/png", :message => "error massage"
     belongs_to :user
    delegate :url, :path, to: :uploaded_image, allow_nil: true, prefix: false
end

如何委派从图像错误用户如果：uploaded_image是无效的？

例如：

user_image = user.images.build(uploaded_image: new_image.path)
user_image.save

应该上升一个错误，如果uploaded_image无效。

Answer 1:

轨有validates_associated助手（在Mongoid也可用），这将调用valid? 于相关联的对象中的每一个。

对于validates_associated的默认错误信息是“无效”。 需要注意的是每个关联对象将包含它自己的错误集合; 错误不冒泡需要调用模型。

Rails的指南：活动记录验证

class User
  include Mongoid::Document

  has_many :images
  accepts_nested_attributes_for :image
  validates_associated :images
end

请注意 ，你不应该添加validates_associated :user对Image ，因为它会导致无限循环。

您可以访问错误的嵌套的图像，如下所示：

<% if @user.errors.any? %>
  <div id="error_explanation">
    <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>
    <ul>
    <% @user.errors.full_messages.each do |msg| %>
      <li><%= msg %></li>
    <% end %>
    </ul>
    <% if @user.images.any? %>
    <ul>
      <% @user.images.each do |image| %>
        <% if image.errors.any? %>
        <li>
          <ul>
            <% image.errors.full_messages.each do |msg| %>
            <li><%= msg %></li>
            <% end %>
          </ul>
        </li>
        <% end %>
      <% end %>
    </ul>
    <% end %>
  </div>
<% end %>

文章来源: Ruby on Rails - How to delegate error messages from nested model