Rails如何创建具有多态关联的新记录？

Question

我有一个 Location 模型，它通过 :locatable 实现多态

一个Event 有一个Location：

class Event < ApplicationRecord
  has_one :location, as: :locatable
end

在events_controller#create 中，如何使用通过参数传入的位置创建一个新事件？

def create
  property = Event.create! params.require(:event).permit(:name, :time, :location, :organizer_id, attachments: [])
  # ... other stuff, and finally render JSON response
  end

但是，Event.location 是 nil。如何为活动创建地点？

谢谢

Answer 1

locations 表包含一个名为locatable_id 的外键，它与events 表建立多态关联。

创建一个属于event的location：

events_controller.rb

def create
  event = Event.new(event_params)
  location = event.location.build() #or event.location.build(location_parms)
  location.save #will create record in events as well as location associated with the event
end

private
  def event_params
     #Whitelist only events attributes
     params.require(:event).permit(:name, :time, :organizer_id, attachments: [])
  end