Paperclipポリモーフィックモデルのネストされた属性が保存されない（RAILS）

Question

私の生活の中で、私のペーパークリップ添付ファイルの特定の属性がネストされた属性を介してデータベースに保存されない理由を理解できません。私の投稿には1つの添付ファイルがありますが、：attachment属性のmediaパラメータは保存されていませんが、添付ファイルオブジェクトは作成されています。私は、私の強いパラムが引き継がれている方法で何かがうんざりしていると思います。事前に感謝します。

NILの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> 

スキーマ：

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 

ポストモデル：

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

郵便コントローラ：

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 

アタッチメントモデル：

class Attachment < ActiveRecord::Base 

    belongs_to :attachable, polymorphic:true 
    has_attached_file :media 
end 

HTMLのFORM：

<%=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%> 

ログインダム：

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

あなたのfields_forに結合していませんあなたのフォーム。試してみてください：

<%=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%>