我有三种模式：
class User < ActiveRecord::Base
has_many :administrations
has_many :calendars, through: :administrations
end
class Calendar < ActiveRecord::Base
has_many :administrations
has_many :users, through: :administrations
end
class Administration < ActiveRecord::Base
belongs_to :user
belongs_to :calendar
end
这是我的路线：
resources :users do
resources :administrations
resources :calendars
end
-----------
更新
以下是我在终端中运行rake routes时得到的结果：
Prefix Verb URI Pattern Controller#Action
user_administrations GET /users/:user_id/administrations(.:format) administrations#index
POST /users/:user_id/administrations(.:format) administrations#create
new_user_administration GET /users/:user_id/administrations/new(.:format) administrations#new
edit_user_administration GET /users/:user_id/administrations/:id/edit(.:format) administrations#edit
user_administration GET /users/:user_id/administrations/:id(.:format) administrations#show
PATCH /users/:user_id/administrations/:id(.:format) administrations#update
PUT /users/:user_id/administrations/:id(.:format) administrations#update
DELETE /users/:user_id/administrations/:id(.:format) administrations#destroy
user_calendars GET /users/:user_id/calendars(.:format) calendars#index
POST /users/:user_id/calendars(.:format) calendars#create
new_user_calendar GET /users/:user_id/calendars/new(.:format) calendars#new
edit_user_calendar GET /users/:user_id/calendars/:id/edit(.:format) calendars#edit
user_calendar GET /users/:user_id/calendars/:id(.:format) calendars#show
PATCH /users/:user_id/calendars/:id(.:format) calendars#update
PUT /users/:user_id/calendars/:id(.:format) calendars#update
DELETE /users/:user_id/calendars/:id(.:format) calendars#destroy
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PATCH /users/:id(.:format) users#update
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
root GET / static_pages#home
-----------
更新2 ：
这是我的calendars_controller.rb文件：
class CalendarsController < ApplicationController
before_action :set_calendar, only: [:show, :edit, :update, :destroy]
# GET /calendars
# GET /calendars.json
def index
@calendars = Calendar.all
end
# GET /calendars/1
# GET /calendars/1.json
def show
end
# GET /calendars/new
def new
@user = User.find(params[:user_id])
@calendar = @user.calendars.new
end
# GET /calendars/1/edit
def edit
@user = User.find(params[:user_id])
@calendar = @user.calendar.find(params[:calendar_id])
end
# POST /calendars
# POST /calendars.json
def create
@user = User.find(params[:user_id])
@calendar = @user.calendars.new(calendar_params)
respond_to do |format|
if @calendar.save
format.html { redirect_to user_calendar_path(@user,@calendar), notice: 'Calendar was successfully created.' }
format.json { render :show, status: :created, location: @calendar }
else
format.html { render :new }
format.json { render json: @calendar.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /calendars/1
# PATCH/PUT /calendars/1.json
def update
respond_to do |format|
if @calendar.update(calendar_params)
format.html { redirect_to @calendar, notice: 'Calendar was successfully updated.' }
format.json { render :show, status: :ok, location: @calendar }
else
format.html { render :edit }
format.json { render json: @calendar.errors, status: :unprocessable_entity }
end
end
end
# DELETE /calendars/1
# DELETE /calendars/1.json
def destroy
@calendar.destroy
respond_to do |format|
format.html { redirect_to calendars_url, notice: 'Calendar was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_calendar
@calendar = Calendar.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def calendar_params
params.require(:calendar).permit(:name)
end
end
-----------
http://localhost:3000/users/1/calendars/new和http://localhost:3000/users/1/calendars/1工作正常。
但是，每当我尝试访问http://localhost:3000/users/1/calendars时，都会收到以下错误：
ActionController::UrlGenerationError in Calendars#index
Showing /Users/TXC/code/rails/calendy/app/views/calendars/index.html.erb where line #17 raised:
No route matches {:action=>"show", :controller=>"calendars", :id=>nil, :user_id=>nil} missing required keys: [:id, :user_id]
Extracted source (around line #17):
<tr>
<td><%= calendar.name %></td>
<td><%= link_to 'Show', user_calendar_path(@user, @calendar) %></td>
<td><%= link_to 'Edit', edit_user_calendar_path(@user, @calendar) %></td>
<td><%= link_to 'Destroy', calendar, method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
特别是，我不理解missing required keys: [:id, :user_id]部分，因为我@user中有@calendar和user_calendar_path。
显然，我错过了一些东西，但我无法弄清楚是什么。
有什么想法吗？
答案 0 :(得分：2)
问题在于，您正在点击映射到http://localhost:3000/users/1/calendars操作的calendars#index网址，其正确路径为：user_calendars_path且只需要一个参数{{1}因为它会将您带到用户的索引页面，并将显示数据库中的所有用户日历。
但是，在user_id视图中，您有：
index.html.erb您无法拥有，因为您的控制器中的<td><%= link_to 'Edit', edit_user_calendar_path(@user, @calendar) %></td>
操作未设置index和@user。您可以在@calendar中使用此功能，但不能在show.html.erb中使用。所以，这就是你得到这个错误的原因。
简而言之，您不能在index.html.erb中使用：
index.html.erb因为它已映射到<td><%= link_to 'Show', user_calendar_path(@user, @calendar) %></td>
操作，相应的视图应该是calendars#show但是目前您已将其show.html.erb放入其中！
回答您的上一个问题：
特别是，我不明白缺少必需的键：[：id， ：user_id]部分，因为我同时拥有@user和@calendar user_calendar_path。
是的，您在控制器中定义了index.html.erb和@user，并在@calendar方法中show映射到user_calendar_path方法。但是嘿！您是通过与calendars#show操作相对应的index.html.erb来调用此内容的。这就是你所缺少的。希望现在很清楚： - ）
最后，差异很微妙。
calendars#index适用于user_calendars_path视图，其中显示了特定用户的所有日历。在这种情况下，您必须在控制器的index操作中设置@user。
index适用于user_calendar_path，它会将您带到特定用户的特定日历。在这种情况下，您必须在控制器的show方法中设置@user和@calendar。
答案 1 :(得分：1)
您尚未在@user方法中设置@calendar和calendars#show。 new操作会使您的视图很好，但它不知道如何填充参数voor @user和@calendar