捕获到动作控制器异常，Bookings#new 中的 NoMethodError

Question

我正在尝试制作一个用户可以在一个小时的培训中制作一本书的应用。

这是我的 Bookings 控制器：

class BookingsController < ApplicationController
  before_action :load_training,  only: [:create]

  def new
    @booking = Booking.new
    @booking.training_id
  end

  def create
    @booking = @training.bookings.build(booking_params)
    @booking.user = current_user.id

    if @booking.save
      flash[:success] = "Book created"
      redirect_to training_index_url
    else
      render 'new'
    end
  end


  def index
    @booking = Booking.all
  end


  def destroy
    @booking = Booking.find(params[:id])
    @booking.destroy
    flash[:success] = "Book deleted"
    redirect_to training_index_url
  end



private
  def booking_params
    params.require(:booking).permit(:user_id, :training_id)
  end

  def load_training
    @training = Training.find(params[:booking][:training_id])
  end

end

这是我的预订模型：

class Booking < ApplicationRecord
  belongs_to :user
  belongs_to :training
  default_scope -> { order(created_at: :desc) }
  validates :user_id, presence: true
  validates :training_id, presence: true



end

当我尝试在培训中制作这本书时，我收到以下错误：

预订中的 NoMethodError#new 显示 /home/cesar/Apps/boxApp/app/views/bookings/new.html.erb 其中第 6 行 提出：

未定义的方法`bookings_path' 你的意思是？ book_path

我的路线.rb：

Rails.application.routes.draw do

  root 'static_pages#home'
  get    '/signup',               to: 'users#new'
  get    '/contact',              to: 'static_pages#contact'
  get    '/about',                to: 'static_pages#about'
  get    '/login',                to: 'sessions#new'
  post   '/login',                to: 'sessions#create'
  delete '/logout',               to: 'sessions#destroy'
  get    '/book',                 to: 'bookings#new'
  post   '/book',                 to: 'bookings#create'
  delete '/unbook',               to: 'bookings#destroy'


  resources :account_activations, only: [:edit]
  resources :password_resets,     only: [:new, :create, :edit, :update]

  resources :trainings do
    resources :bookings
  end
  resources :users
end

我的 new.html.erb 预订视图：

<div class="row">
  <div class="col-md-6 col-md-offset-3">
<%= form_for ([@training, @booking]) do |f| %>
<%= f.hidden_field :training_id %>
<%= f.submit "Confirm book", class: "btn btn-primary" %>
<% end %>

我现在想知道为什么会出现此错误以及如何修复它以便可以成功完成这本书。

show.html.erb 训练视图：

<% provide(:title, 'Clase | Ludus app') %>
<div class="row">
    <section>
      <h1>
HOUR: <%= @training.hour %>
      </h1>
    </section>
    <section>
      <h1>
SLOTS: <%= @training.slots %>
      </h1>
    </section>
    <center>
    <%= render 'bookings/booking_form' if logged_in? %>
    <%= render 'bookings/show_bookings' if logged_in? %>
  </center>

booking_form：

<% unless current_user?(@user) %>
      <% if current_user.bookings(@training) %>
        <%= link_to "Book", new_training_booking_path(@training), class: "btn btn-primary" %>

rake routes 命令的输出：

                 Prefix Verb   URI Pattern                                         Controller#Action
                   root GET    /                                                   static_pages#home
                 signup GET    /signup(.:format)                                   users#new
                contact GET    /contact(.:format)                                  static_pages#contact
                  about GET    /about(.:format)                                    static_pages#about
                  login GET    /login(.:format)                                    sessions#new
                        POST   /login(.:format)                                    sessions#create
                 logout DELETE /logout(.:format)                                   sessions#destroy
                   book GET    /book(.:format)                                     bookings#new
                        POST   /book(.:format)                                     bookings#create
                 unbook DELETE /unbook(.:format)                                   bookings#destroy
edit_account_activation GET    /account_activations/:id/edit(.:format)             account_activations#edit
        password_resets POST   /password_resets(.:format)                          password_resets#create
     new_password_reset GET    /password_resets/new(.:format)                      password_resets#new
    edit_password_reset GET    /password_resets/:id/edit(.:format)                 password_resets#edit
         password_reset PATCH  /password_resets/:id(.:format)                      password_resets#update
                        PUT    /password_resets/:id(.:format)                      password_resets#update
      training_bookings GET    /trainings/:training_id/bookings(.:format)          bookings#index
                        POST   /trainings/:training_id/bookings(.:format)          bookings#create
   new_training_booking GET    /trainings/:training_id/bookings/new(.:format)      bookings#new
  edit_training_booking GET    /trainings/:training_id/bookings/:id/edit(.:format) bookings#edit
       training_booking GET    /trainings/:training_id/bookings/:id(.:format)      bookings#show
                        PATCH  /trainings/:training_id/bookings/:id(.:format)      bookings#update
                        PUT    /trainings/:training_id/bookings/:id(.:format)      bookings#update
                        DELETE /trainings/:training_id/bookings/:id(.:format)      bookings#destroy
              trainings GET    /trainings(.:format)                                trainings#index
                        POST   /trainings(.:format)                                trainings#create
           new_training GET    /trainings/new(.:format)                            trainings#new
          edit_training GET    /trainings/:id/edit(.:format)                       trainings#edit
               training GET    /trainings/:id(.:format)                            trainings#show
                        PATCH  /trainings/:id(.:format)                            trainings#update
                        PUT    /trainings/:id(.:format)                            trainings#update
                        DELETE /trainings/:id(.:format)                            trainings#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

Answer 1

预订中的 NoMethodError#new 显示 /home/cesar/Apps/boxApp/app/views/bookings/new.html.erb 其中第 6 行 提出：

的未定义方法 `bookings_path' 你有吗 意思是？ book_path

您在new.html.erb 中有<%= form_for ([@training, @booking]) do |f| %>，但@training 对于new 方法不可用。 因为你已经设置了before_action仅用于创建方法。

变化

before_action :load_training,  only: [:create]

到

before_action :load_training,  only: [:new,:create]

应该修复错误。

像下面这样更改new 方法应该可以修复错误

def new
  @booking = Booking.new
  @training = Training.find(params[:training_id])
  @booking.training_id
end