参数在Controllers#create中缺失

Question

我试着做一个应用，当一个用户可以预订一个培训小时。当我试图创建这本书时，我会收到以下方法：

操作控制器：：BookingsController#create中的参数错误 param丢失或值为空:预订

这位是我的订票控制器：

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

  def new
    @booking = Booking.new
  end

  def create
    @booking = @training.bookings.build(booking_params)
    @booking.user = current_user
    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_by(params[:training_id])
  end
end

我不知道为什么它不接受user_id参数到预订，我注意到，因为我把@user在创建方法，其结果是零。当我和用户一起做这件事时，我得到了一个肯定的答案(id，小时，插槽，等等)。

这是我的预订模式：

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

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 :bookings,            only: [:create, :destroy]
  resources :training
  resources :users
end

新订位意见：

<h1>Booking confirmation</h1>

<%= form_for (@booking) do |f| %>
  <%= f.submit "Book", class: "btn btn-primary" %>
<% end %>

现在我想知道为什么预订方法不检索user_id参数。

这就是我在帖子中看到的：

Started POST "/bookings" for 127.0.0.1 at 2017-03-09 00:31:53 -0400
Processing by BookingsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"EUoo8M66O2XlRgeMoEsSqwH2i/EKKFzMMRsY9UilzcU+T+5n6/Gjx0abxlZ7nJlqgr5wsALtXW/UMf2Q01pNUg==", "commit"=>"Reservar"}
  Training Load (0.1ms)  SELECT  "trainings".* FROM "trainings" LIMIT ?  [["LIMIT", 1]]
Completed 400 Bad Request in 2ms (ActiveRecord: 0.1ms)



ActionController::ParameterMissing (param is missing or the value is empty: booking):

app/controllers/bookings_controller.rb:36:in `booking_params'
app/controllers/bookings_controller.rb:9:in `create'
  Rendering /home/cesar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/actionpack-5.0.1/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb wi

谢谢

Answer 1

代码的问题是您没有从预订视图发送user_id和training_id。

您应该拥有user_id (可以是一个隐藏字段)和training_id (用于用户选择的培训)。

<%= f.hidden_field :user_id, value: current_user.id %>

如果用户一次可以预订多个培训，则可以使用多选择选项列出培训列表。

It用户只能在一个事务中预订一次培训，针对每一次培训的复选框应该可以做到这一点。

<ul>
  <% @trainings.each do |training| %>
      <li>
        <%= check_box_tag 'training_ids[]', training.id -%>
        <%= h training.name -%>
      </li>
  <% end %>
</ul>

当用户提交此文件时，您将得到user_id和training_ids以及training_ids = ["1", "2", "3"]。