在Rails中使用红宝石中的私有方法

Question

I've two private methods in my event.rb model an I want these two methods should invoke on two different actions in my events controller.

event.rb

    private 

  def create_notification_on_accept
    self.notifications.create(action_type: "Accept", actor_id: participant.id,
    user_id: user_id)
 end

 def create_notification_on_reject
  self.notifications.create(action_type: "Reject", actor_id: participant.id,
  user_id: user_id)
end

events_controller.rb

  def accept_invitation
   @participants.where(user_id: current_user.id).update_all(is_attending: true)
   render "update"
 end

def reject_invitation
 @participants.where(user_id: current_user.id).update_all(is_attending: false)
 render "update"
end

How can I call these two private mathods in my controller.?

Any suggestions are helpful.

Answer 1

There are no private methods in ruby (as we all know as in Java), you can call them with the Object#send method.

http://ruby-doc.org/core-2.2.0/Object.html#method-i-send

Answer 2

You can make them class methods to call them in your controllers.

 private 

 def self.create_notification_on_accept(event)
   # I don't know where are you getting participant id, so pass it if you need
   # additionally, if they are available on event object then you could do
   # event.participant.id, event.user_id since the background of the code is not given
   # hence I'm making some assumptions 
   event.notifications.create(action_type: "Accept", actor_id: participant.id,
   user_id: user_id)
 end

 def self.create_notification_on_reject(event)
   event.notifications.create(action_type: "Reject", actor_id: participant.id,
 user_id: user_id)
 end

And in your controller you can do this

def accept_invitation
   #find event so you can pass it as a param
   Event.create_notification_on_accept(event)
   @participants.where(user_id: current_user.id).update_all(is_attending: true)
   render "update"
end

However, a better thing to do this would be to have callbacks instead of class methods. That way you can reduce the overhead of calling the method everywhere, instead you can leave it onto the model to know when to call.

Answer 3

You can not call private methods, there is no way for it directly. You could create wrappers that are those methods but as public. Best solution move them to public segemnt

Answer 4

There are a number of ways to get these methods to fire when your particular controller actions are fired.

1. Make them callbacks, these could fire when you save the event. See http://guides.rubyonrails.org/active_record_callbacks.html

2. Put the methods in a service layer object, which updates the participants, and creates the notifications. In this case your controller methods could create a new Reply instance. The Reply class could then have methods to update_participants, and create_notification

In general if you want to call, or test private methods, then think of this as an indicator that these methods want to be public methods, probably in another class.