创建嵌套资源时，Rails 路由错误与 respond_with

Question

我正在创建的简单 Rails 3 应用程序遇到以下问题。这让我抓狂。

我的模型：

class Vehicle < ActiveRecord::Base
    has_many :vehicle_pictures, :dependent => :destroy
def

class VehiclePicture < ActiveRecord::Base
   belongs_to :vehicle
end

我的routes.rb：

MyApp::Application.routes.draw do
    resources :vehicles do
        resources :pictures, :controller => :vehicle_pictures
    end
end

我的rake paths输出：

    vehicle_pictures GET    /vehicles/:vehicle_id/pictures(.:format)            {:action=>"index", :controller=>"vehicle_pictures"}
                     POST   /vehicles/:vehicle_id/pictures(.:format)            {:action=>"create", :controller=>"vehicle_pictures"}
 new_vehicle_picture GET    /vehicles/:vehicle_id/pictures/new(.:format)        {:action=>"new", :controller=>"vehicle_pictures"
edit_vehicle_picture GET    /vehicles/:vehicle_id/pictures/:id/edit(.:format)   {:action=>"edit", :controller=>"vehicle_pictures"}
     vehicle_picture GET    /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"show", :controller=>"vehicle_pictures"}
                     PUT    /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"update", :controller=>"vehicle_pictures"}
                     DELETE /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"destroy", :controller=>"vehicle_pictures"}

我的vehicle_pictures_controller.rb：

class VehiclePicturesController < ApplicationController

  before_filter :find_vehicle

  respond_to :html, :json, :xml

  private
  def find_vehicle
    @vehicle = Vehicle.find(params[:vehicle_id])
  end

  public

  # GET /vehicle/:id/pictures
  def index
    @pictures = @vehicle.vehicle_pictures

    respond_with(@pictures)
  end

  # GET /vehicle/:vehicle_id/pictures/new
  def new
    @picture = VehiclePicture.new
    @picture.vehicle = @vehicle

    respond_with(@picture)
  end

  # POST /vehicle/:vehicle_id/pictures
  def create
    @picture = @vehicle.vehicle_pictures.build(params[:vehicle_picture])

    flash[:notice] =  'Vehicle picture was successfully created.' if @picture.save

    respond_with(@picture)
  end

  # GET /vehicle/:vehicle_id/pictures/:id
  def show
    @picture = @vehicle.vehicle_pictures.find(params[:id])
    respond_with(@picture)
  end

  # DELETE /vehicle/:vehicle_id/pictures/:id
  def destroy
    @picture = @vehicle.vehicle_pictures.find(params[:id])
    @picture.destroy
    respond_with(@picture)
  end

end

当我发布新的车辆图片时，创建方法会按预期调用，但我收到此错误：

No route matches {:controller=>"vehicle_pictures", :action=>"show", :vehicle_id=>#<VehiclePicture id: 24, created_at: "2011-04-08 15:07:53", updated_at: "2011-04-08 15:07:53", picture: nil, description: "", vehicle_id: 1>}

如果我更改 < code>respond_with 到 respond_with(@picture, :location =>vehicle_picture_url(@vehicle.id, @picture.id)) 事情有效。

但据我了解，我不应该这样做。我做错了什么？

Answer 1

还花很多时间在那个东西上。
你应该使用：

  respond_with(@vehicle, @picture)

Answer 2

在某些情况下，这也是有道理的：

respond_with(:admin,@picture)