在rails中传递嵌套属性的参数

Question

我有一个表单，其中有我试图保存的“嵌套属性”。我今天下午才知道这些，而且我是 Rails 新手，所以我会尽力解释这一点。

我有两个模型，画廊和展览照片。前者“has_many”和后者“belongs_to”彼此。 “展览照片”通过画廊控制器上传。

我可以提交表单，但嵌套属性（图像）根本没有被保存。

这是有问题的控制器

def update
  @gallery = Gallery.friendly.find params[:id]

  if @gallery.update(gallery_params)
     redirect_to '/'
  else
     render '/new'
  end
end

def edit
  @gallery = Gallery.friendly.find params[:id]
end

private
def gallery_params 
  params.require(:gallery).permit(:title, exhibition_images: [:image])

end

之所以更新和编辑而不是新建，是因为 Gallery 模型的一个实例是在其父模型创建时创建的。

这里是编辑表格

<%= bootstrap_form_for(@gallery, layout: :horizontal, label_col: "col-sm-2", control_col: "col-sm-10") do |f| %>
  <%= f.text_field :title %>    

  <%= f.fields_for :exhibition_images do |f| %>
    <%= f.file_field :exhibition_image, help: "Ensure images are minimum 400x400px"  %>
  <% end %>
 <%= f.submit "Create/Update", class: "btn btn-primary" %>
<% end %> 

画廊模型

class Gallery < ActiveRecord::Base
  extend FriendlyId
  friendly_id :title, use: :slugged
  belongs_to :guide
  has_many :exhibition_images
  accepts_nested_attributes_for :exhibition_images

展览模型

class ExhibitionImage < ActiveRecord::Base
  belongs_to :gallery

  has_attached_file :image, styles: { small: "100x100", guide: "500x500" }
  validates_attachment_content_type :image, :content_type => ["image/jpg", "image/jpeg", "image/png", "image/gif"]

end

现在我确信有一种更好、更清洁的方法可以做到这一点，如果有人可以解释或展示，我将不胜感激。但最重要的是，我想让这件事发挥作用。

更新

添加了开发日志

Started PATCH "/galleries/martin-bates-geoff-brindle" for 127.0.0.1 at 2014-07-01 00:27:48 +0100
Processing by GalleriesController#update as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"JzFnQgV4ZBoh176xdphPtH/AJsm/BE1N+LWtTUTOgx8=", "gallery"=>{"title"=>"BLAH BLAH BLAH", "exhibition_images_attributes"=>{"0"=>{"image"=>#<ActionDispatch::Http::UploadedFile:0x00000104355c28 @tempfile=#<Tempfile:/var/folders/ns/ry6z7jfd6qg6j8xr2q6dw0yc0000gn/T/RackMultipart20140701-28390-1lfmco8>, @original_filename="oasis.gif", @content_type="image/gif", @headers="Content-Disposition: form-data; name=\"gallery[exhibition_images_attributes][0][image]\"; filename=\"oasis.gif\"\r\nContent-Type: image/gif\r\n">}}}, "commit"=>"Create/Update", "id"=>"martin-bates-geoff-brindle"}
  Guide Load (0.9ms)  SELECT "guides".* FROM "guides"  WHERE (date_starting > '2014-06-30 23:27:48.391845')  ORDER BY "guides"."date_starting" ASC
  Course Load (0.3ms)  SELECT  "courses".* FROM "courses"   ORDER BY "courses"."id" DESC LIMIT 2
  YearlyGuide Load (0.3ms)  SELECT  "yearly_guides".* FROM "yearly_guides"   ORDER BY "yearly_guides"."id" DESC LIMIT 1
  Gallery Load (0.2ms)  SELECT  "galleries".* FROM "galleries"  WHERE "galleries"."slug" = 'martin-bates-geoff-brindle'  ORDER BY "galleries"."id" ASC LIMIT 1
Unpermitted parameters: exhibition_images_attributes
   (0.1ms)  BEGIN
   (0.1ms)  COMMIT
Redirected to http://localhost:5000/
Completed 302 Found in 7ms (ActiveRecord: 1.9ms)

Answer 1

对于回形针，使用 image 而不是 exibition_image

<%= f.file_field :image, help: "Ensure images are minimum 400x400px"  %>