Paperclip多態模型上的嵌套屬性沒有得到保存（RAILS）

Question

我不能爲了我的生活找出爲什麼我的回形針附件的某些屬性不能通過嵌套屬性保存到數據庫。我的帖子有一個附件，但：：附件屬性的媒體參數未被保存，但正在創建附件對象。我想我有一些事情與我的強烈參數傳入的方式搞砸了。預先感謝。

NIL PARAMS

media_file_name: nil, media_content_type: nil, media_file_size: nil, media_updated_at: nil> 

IRB：

irb(main):001:0> p = Post.last 
     Post Load (0.1ms) SELECT "posts".* FROM "posts" ORDER BY "posts"."id" DESC LIMIT 1 
    => #<Post id: 40, body: "test info", expiration: 1467065130586, created_at: "2016-06-27 21:05:41", updated_at: "2016-06-27 21:05:41"> 
    irb(main):002:0> p.attachment 
     Attachment Load (0.2ms) SELECT "attachments".* FROM "attachments" WHERE "attachments"."attachable_id" = ? AND "attachments"."attachable_type" = ? LIMIT 1 [["attachable_id", 40], ["attachable_type", "Post"]] 
    => #<Attachment id: 26, attachable_id: 40, attachable_type: "Post", created_at: "2016-06-27 21:05:41", updated_at: "2016-06-27 21:05:41", media_file_name: nil, media_content_type: nil, media_file_size: nil, media_updated_at: nil> 
    irb(main):003:0> 

模式：

ActiveRecord::Schema.define(version: 20160627165514) do 

    create_table "attachments", force: :cascade do |t| 
    t.integer "attachable_id" 
    t.string "attachable_type" 
    t.datetime "created_at",   null: false 
    t.datetime "updated_at",   null: false 
    t.string "media_file_name" 
    t.string "media_content_type" 
    t.integer "media_file_size" 
    t.datetime "media_updated_at" 
    end 

    add_index "attachments", ["attachable_type", "attachable_id"], name: "index_attachments_on_attachable_type_and_attachable_id" 

    create_table "posts", force: :cascade do |t| 
    t.text  "body" 
    t.integer "expiration", limit: 8 
    t.datetime "created_at",   null: false 
    t.datetime "updated_at",   null: false 
    end 

end 

郵政型號：

class Post < ActiveRecord::Base 
    has_one :attachment, as: :attachable, dependent: :destroy 
    accepts_nested_attributes_for :attachment 
end 

柱控制器：

class PostsController < ApplicationController 

    def show 
     #I don't need this. 
    end 

    def index 
     @posts = Post.all 
    end 

    def new 
     @post = Post.new 
     @post.build_attachment 
    end 

    def create 
     @post = Post.new(post_params) 
     @post.build_attachment 
     if @post.save 
      respond_to do |format| 
       format.html {redirect_to(posts_path, notice:"Post succesfully created")} 
       format.js 
      end 
     else 
      render :new 
     end 
    end 


    private 

    def post_params 
     params.require(:post).permit(:body,:expiration, attachment_attributes: [:media]) 
    end 


end 

附件型號：

class Attachment < ActiveRecord::Base 

    belongs_to :attachable, polymorphic:true 
    has_attached_file :media 
end 

HTML表單：

<%=form_for(@post, url: posts_path, html:{multipart:true}) do |form|%> 
     <%=form.text_area :body%> 

     <%=fields_for(:attachment) do |ff|%> 
      <%= ff.file_field :media %> 
     <%end%> 


    <%=form.hidden_field :expiration%> 
    <%=form.submit "Post", class: "post-submit-button"%> 



<%end%> 

登錄阿呆：

Started POST "/posts" for ::1 at 2016-06-27 16:05:41 -0500 
Processing by PostsController#create as HTML 
    Parameters: {"utf8"=>"✓", "authenticity_token"=>"/b54OJOBJIaR551MAHDujCxjciI7OAx93EQAVrugCz0xtYnafaSH4widYOftZJUbDHLfmI6jly5eG5AxCCNJbQ==", "post"=>{"body"=>"test info", "expiration"=>"1467065130586"}, "attachment"=>{"media"=>"IMG_1004.jpg"}, "commit"=>"Post"} 
    (0.1ms) begin transaction 
    SQL (0.3ms) INSERT INTO "posts" ("body", "expiration", "created_at", "updated_at") VALUES (?, ?, ?, ?) [["body", "test info"], ["expiration", 1467065130586], ["created_at", "2016-06-27 21:05:41.321484"], ["updated_at", "2016-06-27 21:05:41.321484"]] 
    SQL (0.1ms) INSERT INTO "attachments" ("attachable_type", "attachable_id", "created_at", "updated_at") VALUES (?, ?, ?, ?) [["attachable_type", "Post"], ["attachable_id", 40], ["created_at", "2016-06-27 21:05:41.323335"], ["updated_at", "2016-06-27 21:05:41.323335"]] 
    (1.4ms) commit transaction 
Redirected to http://localhost:3000/posts 
Completed 302 Found in 8ms (ActiveRecord: 1.9ms) 


Started GET "/posts" for ::1 at 2016-06-27 16:05:41 -0500 
Processing by PostsController#index as HTML 
    Rendered layouts/_user_menu.html.erb (0.1ms) 
    Rendered posts/index.html.erb within layouts/application (1.8ms) 
Completed 200 OK in 26ms (Views: 25.8ms | ActiveRecord: 0.0ms) 

Answer 1

你不綁定您的fields_for到你的形式。試試這個：

<%=form_for(@post, url: posts_path, html:{multipart:true}) do |form|%> 
    <%=form.text_area :body%> 
    <%= form.fields_for(:attachment) do |ff|%> 
    <%= ff.file_field :media %> 
    <% end %> 
    <%=form.hidden_field :expiration%> 
    <%=form.submit "Post", class: "post-submit-button"%> 
<%end%>