我有一个嵌套模型设置，其中用户有多个制造商，制造商有多个生产线。当我尝试从行索引中删除该行的实例时，我收到一条错误的路由消息。我不确定我做错了什么，但这可能很简单，希望有人能在这里拯救我一些心痛。我已经阅读了 hartl 的资料，但我对嵌套资源和路由仍然非常陌生。

===模型===

class User < ActiveRecord::Base
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
  has_many :manufacturers
end

======

class Manufacturer < ActiveRecord::Base
  belongs_to :user
  has_many :lines
end

======

class Line < ActiveRecord::Base
  belongs_to :manufacturer
end

======

lines_controller.rb

class LinesController < ApplicationController
  before_action :set_line, only: [:show, :edit, :update, :destroy]
  before_filter :load_manufacturer

  # GET /lines
  # GET /lines.json
  def index
    @lines = Line.all
  end

  # GET /lines/1
  # GET /lines/1.json
  def show
  end

  # GET /lines/new
  def new
    @manufacturer = Manufacturer.find(params[:manufacturer_id])
    @line = @manufacturer.lines.build
  end

  # GET /lines/1/edit
  def edit
  end

  # POST /lines
  # POST /lines.json
  def create
    @line = @manufacturer.lines.build(line_params)

    respond_to do |format|
      if @line.save
        format.html { redirect_to manufacturer_line_path(@manufacturer, @line), notice: 'Line was successfully created.' }
        format.json { render action: 'show', status: :created, location: @line }
      else
        format.html { render action: 'new' }
        format.json { render json: @line.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /lines/1
  # PATCH/PUT /lines/1.json
  def update
    respond_to do |format|
      if @line.update(line_params)
        format.html { redirect_to manufacturer_line_path(@manufacturer, @line), notice: 'Line was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @line.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /lines/1
  # DELETE /lines/1.json
  def destroy
    @manufacturer.line.destroy
    respond_to do |format|
      format.html { redirect_to lines_url }
      format.json { head :no_content }
    end
  end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def line_params
      params.require(:line).permit(:name, :manufacturer_id)
    end

    def load_manufacturer
      @manufacturer = Manufacturer.find(params[:manufacturer_id])
    end
end

=====

                  Prefix Verb   URI Pattern                                              Controller#Action
      manufacturer_lines GET    /manufacturers/:manufacturer_id/lines(.:format)          lines#index
                         POST   /manufacturers/:manufacturer_id/lines(.:format)          lines#create
   new_manufacturer_line GET    /manufacturers/:manufacturer_id/lines/new(.:format)      lines#new
  edit_manufacturer_line GET    /manufacturers/:manufacturer_id/lines/:id/edit(.:format) lines#edit
       manufacturer_line GET    /manufacturers/:manufacturer_id/lines/:id(.:format)      lines#show
                         PATCH  /manufacturers/:manufacturer_id/lines/:id(.:format)      lines#update
                         PUT    /manufacturers/:manufacturer_id/lines/:id(.:format)      lines#update
                         DELETE /manufacturers/:manufacturer_id/lines/:id(.:format)      lines#destroy
           manufacturers GET    /manufacturers(.:format)                                 manufacturers#index
                         POST   /manufacturers(.:format)                                 manufacturers#create
        new_manufacturer GET    /manufacturers/new(.:format)                             manufacturers#new
       edit_manufacturer GET    /manufacturers/:id/edit(.:format)                        manufacturers#edit
            manufacturer GET    /manufacturers/:id(.:format)                             manufacturers#show
                         PATCH  /manufacturers/:id(.:format)                             manufacturers#update
                         PUT    /manufacturers/:id(.:format)                             manufacturers#update
                         DELETE /manufacturers/:id(.:format)                             manufacturers#destroy
        new_user_session GET    /users/sign_in(.:format)                                 devise/sessions#new
            user_session POST   /users/sign_in(.:format)                                 devise/sessions#create
    destroy_user_session DELETE /users/sign_out(.:format)                                devise/sessions#destroy
           user_password POST   /users/password(.:format)                                devise/passwords#create
       new_user_password GET    /users/password/new(.:format)                            devise/passwords#new
      edit_user_password GET    /users/password/edit(.:format)                           devise/passwords#edit
                         PATCH  /users/password(.:format)                                devise/passwords#update
                         PUT    /users/password(.:format)                                devise/passwords#update
cancel_user_registration GET    /users/cancel(.:format)                                  devise/registrations#cancel
       user_registration POST   /users(.:format)                                         devise/registrations#create
   new_user_registration GET    /users/sign_up(.:format)                                 devise/registrations#new
  edit_user_registration GET    /users/edit(.:format)                                    devise/registrations#edit
                         PATCH  /users(.:format)                                         devise/registrations#update
                         PUT    /users(.:format)                                         devise/registrations#update
                         DELETE /users(.:format)                                         devise/registrations#destroy
                    root GET    /                                                        pages#home
                   about GET    /about(.:format)                                         pages#about
                         GET    /users/:id(.:format)                                     users#show
               all_users GET    /users(.:format)                                         users#index
          public_profile GET    /users/:name(.:format)                                   users#show

======

app/views/lines/index.html.erb

<h1>Listing lines</h1>

<table>
  <thead>
    <tr>
      <th>Name</th>
      <th>Manufacturer</th>
      <th></th>
      <th></th>
      <th></th>
    </tr>
  </thead>

  <tbody>
    <% @lines.each do |line| %>
      <tr>
        <td><%= line.name %></td>
        <td><%= line.manufacturer_id %></td>
        <td><%= link_to 'Show', manufacturer_lines_path(line.manufacturer, line) %></td>
        <td><%= link_to 'Edit', edit_manufacturer_line_path(line.manufacturer, line) %></td>
        <td><%= link_to 'Destroy', manufacturer_lines_path, method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>

<br>

最佳答案

这是试图使用错误的路由助手:

<td><%= link_to 'Destroy', manufacturer_lines_path, method: :delete, data: { confirm: 'Are you sure?' } %></td>

应该是:

<td><%= link_to 'Destroy', manufacturer_line_path(line.manufacturer, line), method: :delete, data: { confirm: 'Are you sure?' } %></td>

manufacturer_lines_path 正在做的是使用路由助手生成一个路径，例如 /manufacturers/1/lines，这是完全有效的。 无效 的是此链接正在向该路由发出 DELETE 请求，如果您查看 rake routes 输出，您会看到你没有为此的路线。您可能只有一个用于 GET，另一个用于 POST，但没有用于 DELETE。

所以解决方案是使用正确的路径助手，manufacturer_line_path，它需要一个 Manufacturer 对象和一个 Line 对象，并从中获取它生成一条路线，例如 /manufacturers/1/lines/2。同样，查看 rake routes 的输出，您会看到您为该路径定义了几个路由。 GET、PUT、PATCH 和 DELETE。

这最后一条路线是当您发出 DELETE/manufacturers/1/lines/2 请求时要匹配的内容，您的应用程序的路由器会将其路由到 LinesController的destroy Action ，参数中传入manufacturer_id=1和id=2

关于ruby-on-rails - 没有路由匹配嵌套资源的 [DELETE]，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22468307/