Rails 4：嵌套资源的正确语法 - @user 或 :user？

Question

我对嵌套资源使用简单的形式。

   resources :users do
      resources :interests
   end

我的 InterestsController 中有以下回调

 class InterestsController < ApplicationController
     before_action :set_interest, only: [:show, :create, :edit, :update,  :destroy]
     before_action :set_user, only: [:index, :show, :create, :edit, :update, :destroy]


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

    def set_user
      @user = current_user
    end
end

我有一个简单的表格 - 这很有效......

<%= simple_form_for [:user, @interest] do |f| %>

  <% if @interest.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@interest.errors.count, "error") %> prohibited this response from being saved:</h2>

      <ul>
        <% @interest.errors.full_messages.each do |message| %>
            <li><%= message %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

   <div class="form-inputs">
     <%= f.input :user_id %>
     <%= f.input :discipline_id %>
   </div>

  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

但这并没有.....

<%= simple_form_for [@user, @interest] do |f| %>

我找不到任何解释 - 简单形式的 @user 肯定是正确的，是声明用户？

这里有更多信息：

这是我在编辑操作时遇到的错误：

  No route matches {:action=>"show", :controller=>"interests", :format=>nil, :id=>nil, :user_id=>#<Interest id: 1, user_id: 1, discipline_id: 10, created_at: "2015-02-22 11:00:14", updated_at: "2015-02-22 11:00:14">} missing required keys: [:id]

有趣的是，新操作有效。如果我将简单形式切换为

<%= simple_form_for [@user, @interest] do |f| %>

编辑操作有效，但新操作无效。所以我猜这一定是我设置我的 InterestsController 的方式。

这里是完整的。

 class InterestsController < ApplicationController
    before_action :set_interest, only: [:show, :create, :edit, :update, :destroy]
    before_action :set_user, only: [:index, :show, :create, :edit, :update, :destroy]


  def index
    @users_interests = @user.interests
  end


  def show
  end


  def new
    @interest = current_user.interests.new
  end


  def edit
  end

  def create
    @interest = User.find(params[:user_id]).interests.build(interest_params)
    @interest.user = current_user
    respond_to do |format|
    if @interest.save
      flash[:success] = "Interest created!"
          format.html { redirect_to user_interests_path(current_user) }
          format.json { render :show, status: :created, location: @interest }
     else
         flash[:failure] = "Interest was not added!"
         format.html { render :new }
         format.json { render json: @interest.errors, status: :unprocessable_entity }
     end
   end
 end


 def update
   respond_to do |format|
   if @interest.update(interest_params)
     format.html { redirect_to user_interests_path(current_user) }
     format.json { render :show, status: :ok, location: @interest }
   else
     format.html { render :edit }
     format.json { render json: @interest.errors, status: :unprocessable_entity }
    end
  end
end

def destroy
    @interest.destroy
    respond_to do |format|
    format.html { redirect_to interests_url, notice: 'Interest was successfully destroyed.' }
    format.json { head :no_content }
   end
  end

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

    def set_user
      @user = current_user
    end

   # Never trust parameters from the scary internet, only allow the white list through.
     def interest_params
       params.require(:interest).permit(:user_id, :discipline_id)
     end
   end

Answer 1

已解决：

简单修复 - 需要在新操作中设置 @user = current_user：

 def new
    @interest = current_user.interests.new
    @user =current_user
 end