Rails 4，回形针和多态关联

Question

我有2个模型：News和Uploadedfile

class News < ActiveRecord::Base
    has_many :uploadedfiles, as: :parent
    attr_accessible :title, :content, :author
end

class Uploadedfile < ActiveRecord::Base
    belongs_to :parent, polymorphic: true
    has_attached_file :url
    attr_accessible :url_file_name, :url_content_type, :url_file_size, :url_updated_at
end

和形式：

<%= form_for(@news) do |f| %>

    <div class="field">

        <%= f.fields_for :uploadedfile, f.uploadedfile.new do |uf| %>
            <%= uf.label :url %><br>
            <%= uf.file_field :url %>
        <% end %>

    </div>

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

当我提交表格时，我的表格上uploadedfile未更改

问题出在哪儿？ 谢谢！

Answer 1

我认为您已经嵌套了arribute :uploadedfiles

class News < ActiveRecord::Base
     has_many :uploadedfiles, as: :parent
    attr_accessible :title, :content, :author, :uploadedfiles_attributes
    accept_nested_attributes_for :uploadedfiles
end

并以形式：更改：

 <%= f.fields_for :uploadedfile, f.uploadedfile.new do |uf| %>

至：

<%= f.fields_for :uploadedfiles, Uploadedfile.new do |uf| %>

Answer 2

我认为这里不需要多态关联。 这是一种更易读的方法：

class News < ActiveRecord::Base
    has_many :uploadedfiles
    attr_accessible :title, :content, :author
    accept_nested_attributes_for :uploadedfiles
end

class Uploadedfile < ActiveRecord::Base
    belongs_to :news
    has_attached_file :url
    attr_accessible :url_file_name, :url_content_type, :url_file_size, :url_updated_at
end

*请注意，我已经添加了accept_nested_attributes_for

以及形式：

<%= form_for(@news) do |f| %>

    <div class="field">

        <%= f.fields_for :uploadedfiles do |uf| %>
            <%= uf.label :url %><br>
            <%= uf.file_field :url %>
        <% end %>

    </div>

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