ruby-on-rails - 使用回形针的嵌套形式

Question

我有一个名为 posts 的模型，它有很多附件。

附件模型使用回形针。

我制作了一个用于创建附件的独立模型，效果很好，这是此处说明的 View (https://github.com/thoughtbot/paperclip):

<% form_for :attachment, @attachment, :url => @attachment, :html => { :multipart => true } do |form| %>
  <%= form.file_field :pclip %>

  <%= form.submit %>

<% end %>

posts 中的嵌套表单如下所示:

<% @attachment = @posts.attachments.build %>
<%= form_for(@posts) do |f| %>
  <% if @posts.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@posts.errors.count, "error") %> prohibited this post from being saved:</h2>

      <ul>
      <% @posts.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </div>
  <div class="field">
    <%= f.label :description %><br />
    <%= f.text_area :description %>
  </div>
  <div class="field">
    <%= f.fields_for :attachments, @attachment, :url => @attachment, :html => { :multipart => true } do |at_form| %>

      <%= at_form.file_field :pclip %>

    <% end %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

附件记录已创建，但它是空的。文件未上传。同时，帖子已成功创建...

有什么想法吗？

Answer 1

您在表单定义中缺少 :multipart 选项:

<% @attachment = @post.attachments.build %>
<%= form_for @post, :html => { :multipart => true } do |f| %>
  <% if @post.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2>

      <ul>
      <% @post.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </div>
  <div class="field">
    <%= f.label :description %><br />
    <%= f.text_area :description %>
  </div>
  <div class="field">
    <%= f.fields_for :attachments, @attachment do |at_form| %>

      <%= at_form.file_field :pclip %>

    <% end %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

此外，您的@posts 变量实际上应该是@post(单个ActiveRecord 实例而不是ActiveRecord 实例数组)。