避免使用fields_for将单个记录添加到关联模型

Question

我有以下协会:

class Developer < ActiveRecord::Base
  has_many :large_photos, :class_name => 'Photo', :conditions => { :large => true }, :reject_if => proc { |x| x['image'].blank? }
end

class Photo < ActiveRecord::Base
  belongs_to :developer
  mount_uploader :image, ImageUploader # Carrierwave
end

现在,我正在寻找一个开发表单,在提交时,将添加一个文件字段来上传新表单Photo.目前我有:

<%= form_for @developer do |form| %>

    <%= form.fields_for :large_photos do |sf| %>
    <div class="dropzone">
        <%= sf.file_field :image %>
        <%= sf.hidden_field :large, :value => '1' %>
        <%= sf.hidden_field :image_cache %>
    </div>
    <% end %>

<% end%>

现在,我fields_for遇到的问题是循环现有的记录(当然是!),我宁愿避免,我只想添加一个文件字段来上传新照片.我该怎么做？

Answer 1

<%= form.fields_for :large_photos, @developer.large_photos.build do |project_fields| %>

此行不是为每个现有照片创建字段,而是构建一个新的Photo并仅显示该字段的字段(因此字段为空,我认为这是您想要的).