## [[0x0000557526c2b9b0>的未定义方法`booking_items'

Question

我试图在show space API中显示空间的可用性。代码背后的逻辑是可用性=可用空间总数-预订空间总数。有人可以帮我编写代码，因为它是Rails API的新手]

我的空间控制器

# frozen_string_literal: true

# Spaces controller
class Api::V1::SpacesController < ApiController
  before_action :fetch_space, only: [:show]

  def index
    spaces = Space.all
    render_collection(spaces, { name: 'spaces' }, each_serializer: SpaceShortSerializer)
  end

  def show
    render json: @space, serializer: SpaceSerializer
  end

  def create
    if space = current_user.spaces.create(space_params)
      render_object(space, { name: 'space' }, { serializer: SpaceSerializer })
    else
      render_error(space.errors.full_messages)
    end
  end


  private

  def fetch_space
    space_id = params[:space_id] || params[:id]
    @space = Space.find(space_id)
  end

  def space_params
    params.require(:space).permit(:name, :email, :website, :phone,
                                  amenities_attributes: [:id, :name, :available],
                                  meeting_rooms_attributes: [:id, :count, :capacity, pricings_attributes: [:id, :duration, :price]],
                                  private_offices_attributes: [:id, :count, :capacity, pricings_attributes: [:id, :duration, :price]],
                                  desks_attributes: [:id, :count, :desk_type, pricings_attributes: [:id, :duration, :price]],
                                  operating_hours_attributes: [:id, :day, :slot])
  end
end

预订控制器
class Api::V1::BookingsController < ApiController
  before_action :fetch_space, only: [:show]

  def index
    bookings = Booking.all
    render_collection(bookings, { name: 'bookings' }, each_serializer: BookingItemSerializer )
  end
# booking_item_params: params[:entity_type]
  def create
    if booking = current_user.bookings.create(booking_params)
      render_object(booking, { name: 'booking' }, { serializer: BookingSerializer })
    else
      render_error(booking.errors.full_messages)
    end
  end

  private


  def booking_params
    params.require(:booking).permit(:space_id,
      booking_items_attributes: [:id, :entity_type, :entity_id, :count],
      booking_dates_attributes: [:id, :from_date, :to_date, :from_time, :to_time])
    end
  end

空间序列化器
class SpaceSerializer < ActiveModel::Serializer
  attributes :id, :name, :email, :website, :phone, :owner, :available_amenities, :photos

  belongs_to :owner, except: :profile, serializer: OwnerSerializer

  has_many :meeting_rooms, serializer: MeetingRoomSerializer
  has_many :private_offices, serializer: PrivateOfficeSerializer
  has_many :desks, serializer: DeskSerializer
  has_many :operating_hours, serializer: OperatingHourSerializer

  def photos
    Photo::DUMMY_SPACE_IMAGES.shuffle.first(3)
  end
end

预订序列化器
class BookingSerializer < ActiveModel::Serializer
  attributes :id, :user_id, :space_id, :status, :booked
  has_many :booking_items, serializer: BookingItemSerializer

  def booked
    object.booking_items.sum(:count)
  end
end

预订项目序列化器
class BookingItemSerializer < ActiveModel::Serializer

  has_many :meeting_rooms, serializer: MeetingRoomSerializer
  has_many :private_offices, serializer: PrivateOfficeSerializer
  has_many :desks, serializer: DeskSerializer
  has_many :operating_hours, serializer: OperatingHourSerializer


end

会议室序列化器
class MeetingRoomSerializer < ActiveModel::Serializer
  attributes :id, :count, :capacity, :availabitity, :photos
  belongs_to :booking_items, serializer: BookingItemSerializer

  def photos
    Photo::DUMMY_MEETING_ROOM_IMAGES.shuffle.first(2)
  end

  def availabitity
    object.count - object.booking_items.sum(:count)
  end
end

就像在会议室序列化程序中一样，我也需要显示私人办公室和办公桌序列化程序的可用性。
私人办公室序列化器
class PrivateOfficeSerializer < ActiveModel::Serializer
  attributes :id, :count, :capacity, :photos

  def photos
    Photo::DUMMY_PRIVATE_OFFICE_IMAGES.shuffle.first(2)
  end
end

桌面序列化器
class DeskSerializer < ActiveModel::Serializer
  attributes :id, :count, :desk_type, :photos


  def photos
    Photo::DUMMY_DESK_IMAGES.shuffle.first(2)
  end


end

错误堆栈
Completed 500 Internal Server Error in 150ms (ActiveRecord: 28.3ms | Allocations: 46623)



NoMethodError (undefined method `booking_items' for #<MeetingRoom:0x0000557526c2b9b0>):

app/serializers/meeting_room_serializer.rb:10:in `availabitity'
app/controllers/api/v1/spaces_controller.rb:13:in `show'

Answer 1

在您的MeetingRoomSerializer中

更改此行

belongs_to :booking_items, serializer: BookingItemSerializer

到
has_many :booking_items, serializer: BookingItemSerializer