複数のID（Rails 4.2.3）の関連付けを使って作業する

Question

私は最初のRailsプロジェクトを進めています。私はユーザーがログインしボードを作成するアプリケーションを作成しています。このボードはユーザーのIDに固有のものです。そのボードの中で、ユーザーはリストを作成することができます。各リストはにそのボードのIDと結びつけてください。私が持っている問題は、リストを作成することです。それは保存しません。私が見ている具体的なエラーはCould not find the association :memberships in model Listです。リストが理事会のIDにマップされている問題があります。 Railsサーバーの出力を見ると、にはというボード（そのボードのすべてのリストを表示するはずです）にはユーザーIDまたはボードIDがありません。

ユーザーのためのボードを表示

Started GET "/boards" for ::1 at 2016-10-12 14:26:33 -0400 
Processing by BoardsController#index as HTML 
    User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] 
    Board Load (0.1ms) SELECT "boards".* FROM "boards" WHERE "boards"."user_id" = ? [["user_id", 1]] 
    CACHE (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] 
    CACHE (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] 
    CACHE (0.0ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] 
    Rendered boards/index.html.erb within layouts/application (3.4ms) 
    Rendered layouts/_flash.html.erb (0.1ms) 
Completed 200 OK in 168ms (Views: 166.1ms | ActiveRecord: 0.2ms) 

そのユーザー

Started GET "/lists.3" for ::1 at 2016-10-12 14:28:26 -0400 
Processing by ListsController#index as 
    User Load (0.1ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] 
    List Load (0.3ms) SELECT "lists".* FROM "lists" 
    Rendered lists/index.html.erb within layouts/application (2.3ms) 
    Rendered layouts/_flash.html.erb (0.1ms) 
Completed 200 OK in 181ms (Views: 169.2ms | ActiveRecord: 0.9ms) 

関連するコードのためのリストを表示

VS ...

モデル

board.rb

class Board < ActiveRecord::Base 
    belongs_to :owner, class_name: "User", foreign_key: "user_id" 

    has_many :lists 
    has_many :memberships 
    has_many :members, :through => :memberships, :source => :user 
    has_many :lists, :through => :memberships, :source => :board 

    validates_presence_of :title 
    validates_presence_of :owner 

    def is_private? 
    return self.is_private 
    end 
end 

list.rb

class List < ActiveRecord::Base 
    belongs_to :board 
    has_many :cards 

    has_one :board, :through => :memberships, :source => :board 

    validates_presence_of :title 
    validates_presence_of :board 
end 

user.rb

class User < ActiveRecord::Base 
    has_many :boards 
    has_many :lists 
    has_many :cards 
    has_many :memberships 
    has_many :board_memberships, :through => :memberships, :source => :board 
    has_many :list_memberships, :through => :memberships, :source => :board 

    has_secure_password 

    validates :password, 
    length: { :minimum => 8 }, 
    presence: true 

    validates :username, 
    uniqueness: true, 
    presence: true 

    validates_confirmation_of :password 
end 

membership.rb

の

class Membership < ActiveRecord::Base 
    belongs_to :user 
    belongs_to :board 

    validates :user, presence: true, uniqueness: { scope: :board, message: "User is already a member of that board" } 
    validates :board, presence: true 
end 

コントローラ

boards_controller.rb（私はここに関連する部分を追加しました）

class BoardsController < ApplicationController 
     before_action :set_board, only: [:show, :edit, :update, :destroy] 
     before_action :authenticate, except: [:show] 
     before_action :authorize, except: [:show] 
     before_action :authorize_owner, only: [:edit, :update, :destroy] 
     before_action :authorize_membership, only: [:show] 

     # GET /boards 
     # GET /boards.json 
     def index 
     @boards = current_user.boards 
     end 

     # GET /boards/1 
     # GET /boards/1.json 
     def show 
     @lists = current_user.board_id 
     end 

    private 
     def set_board 
      @board = Board.find(params[:id]) 
     end 

     def board_params 
      params.require(:board).permit(:title, :is_private) 
     end 

     def authorize_owner 
      if current_user != @board.owner 
      redirect_to root_url, :notice => 'Board not found or inaccessible' and return 
      end 
     end 

     def authorize_membership 
      return 
      if @board.is_private? 
      if !authenticate 
       redirect_to root_url, :notice => 'Please login first' and return 
      end 

      if @board.owner != current_user || !@board.members.include?(current_user) 
       redirect_to root_url, :notice => 'Board not found or inaccessible' and return 
      end 
      end 
     end 
    # POST /boards 
    # POST /boards.json 
    def create 
    @board = Board.new(board_params) 
    @board.owner = current_user 

    respond_to do |format| 
     if @board.save 
     format.html { redirect_to @board, notice: 'Board was successfully created.' } 
     format.json { render :show, status: :created, location: @board } 
     else 
     format.html { render :new } 
     format.json { render json: @board.errors, status: :unprocessable_entity } 
     end 
    end 
    end 

lists_controller.rb（ファイル全体）

class ListsController < ApplicationController 
    before_action :set_list, only: [:show, :edit, :update, :destroy] 
    before_action :authenticate, except: [:show] 

    # GET /lists 
    # GET /lists.json 
    def index 
    @lists = List.all 
    end 

    # GET /lists/1 
    # GET /lists/1.json 
    def show 
    @lists = current_user.board_id 
    end 

    # GET /lists/new 
    def new 
    @list = List.new 
    end 

    # GET /lists/1/edit 
    def edit 
    end 

    # POST /lists 
    # POST /lists.json 
    def create 
    @list = List.new(list_params) 

    respond_to do |format| 
     if @list.save 
     format.html { redirect_to @list, notice: 'List was successfully created.' } 
     format.json { render :show, status: :created, location: @list } 
     else 
     format.html { render :new } 
     format.json { render json: @list.errors, status: :unprocessable_entity } 
     end 
    end 
    end 

    # PATCH/PUT /lists/1 
    # PATCH/PUT /lists/1.json 
    def update 
    respond_to do |format| 
     if @list.update(list_params) 
     format.html { redirect_to @list, notice: 'List was successfully updated.' } 
     format.json { render :show, status: :ok, location: @list } 
     else 
     format.html { render :edit } 
     format.json { render json: @list.errors, status: :unprocessable_entity } 
     end 
    end 
    end 

    # DELETE /lists/1 
    # DELETE /lists/1.json 
    def destroy 
    @list.destroy 
    respond_to do |format| 
     format.html { redirect_to lists_url, notice: 'List was successfully destroyed.' } 
     format.json { head :no_content } 
    end 
    end 

    private 
    # Use callbacks to share common setup or constraints between actions. 
    def set_list 
     @list = List.find(params[:id]) 
    end 

    # Never trust parameters from the scary internet, only allow the white list through. 
    def list_params 
     params.require(:list).permit(:title, :board_id) 
    end 
end 

私はネストされたモデルについてのいくつかの記事と、Railsのドキュメントを読んでいます。私は知識ギャップがあることを知っているどこか。私は他の人の質問を読んで、解決しようとする試みが失敗したので、どんな方向にも感謝します。

Answer 1

あなたはListオブジェクトが行う、その後Boardオブジェクトの:membershipsにアクセスできるようにしたい場合は...

class List << ActiveRecord::Base 

    delegate :memberships, to: :board 

それは意味がありませんので、 has_one :board, :through => :memberships, :source => :boardを削除...あなたはすでに持っていますボード関係であり、異なるボード関係を作るために使用するメンバーシップ関係はありません。