неопределенный метод `referrals' для #‹User::ActiveRecord_Associations_CollectionProxy:

Я внедряю реферальную систему rails 5.1. Я хочу рефералов до 8-го поколения. У меня есть класс принадлежности, как показано ниже:

class Affiliation < ApplicationRecord
  belongs_to :affiliate, :class_name => "User", :foreign_key => "affiliate_id"
  belongs_to :referred, :class_name => "User", :foreign_key => "referred_id"
     validates_presence_of :affiliate, :referred
     validates_uniqueness_of :referred_id
       private
        def validate
          errors.add_to_base("Affiliate and Referrer can't be the same 
        user.") if affiliate and (affiliate == referred)
        end
       end

мой пользователь.rb

class User < ApplicationRecord
 has_many :affiliations, :foreign_key => "affiliate_id", :dependent => :destroy
   has_many :referrals, :through => :affiliations, :source => :referred
  # map.affiliate_referral 'a/:referrer_code', :controller => 
 'referrals', :action => 'new'
  def affiliate_link
    "https://localhost:3000/members/new/?referrer_code=#
    {self.affiliate_code}"
 end

Теперь реферальная система работает, я могу создавать участников для своих рефералов.

задача состоит в том, как просмотреть 1-е поколение вплоть до 8-го поколения. Я получаю эту ошибку:

undefined method `referrals' for #<User::ActiveRecord_Associations_CollectionProxy:0x00007f48e4c2d2e0>

Я могу рефералов для первого поколения, но со 2-го и выше это не работает.

Любая помощь, пожалуйста...??? Вот мой контроллер приборной панели

class DashboardController < ApplicationController
         def dashboard
                 # storage for referrals and affilations through eight 
         generations

           #generate first generation referrals
             def flatten_scopes(scopes)
            scopes.inject([]) { |a,r| r.is_a?(Array) ? a += flatten_scopes(r) : a.push(r) }
   end

       @firstgeners = referral_gen(current_user)
       @secondgeners ||= []
       @thirdgeners ||= []
       @fourthgeners ||= []
      @fifthgeners ||= []
      @sixthgeners ||= []
     @seventhgeners ||= []
     @eightgeners ||= []
            #loop first generation referrals to get the affiliates to 
         form our second 
        generation affiliations 
        #@firstgeners = @firstgeners1.flatten

        #@secondgeners1 = []
               @firstgeners = flatten_scopes(@firstgeners)
             if  @firstgeners.any?
            @firstgeners.each do |u| 
        if u.referrals.any?

           @secondgeners << u.referrals
           end
       end
        end

      #@secondgeners = @secondgeners1.flatten
      #from second generation referrals generate the affiliations 
      # @thirdgeners1 = []
      @secondgeners = flatten_scopes(@secondgeners)
      if @secondgeners.any?
      @secondgeners.each do |u| 
      if u.referrals.any?
     @thirdgeners << u.referrals
       end
     end
    end
    #@thirdgeners = @thirdgeners1.flatten

     @thirdgeners = flatten_scopes(@thirdgeners)
     #from third generation referrals generate the affiliations
    if @thirdgeners.any?
      @thirdgeners.each do |u| 
     if u.referrals.any?
      @fourthgeners << u.referrals
    end
    end
    end 
    #@fourthgeners = @fourthgeners1.flatten



      #from third generation referrals generate the affiliations
        @fourthgeners = flatten_scopes(@fourthgeners)
        if @fourthgeners.any?
       @fourthgeners.each do |u| 
       if u.referrals.any?
       @fifthgeners << u.referrals
       end
       end
       end 
    # @fifthgeners = @fifthgeners1.flatten

     @fifthgeners = flatten_scopes(@fifthgeners)
     if @fifthgeners.any?
        @fifthgeners.each do |u| 
         if u.referrals.any?
           @sixthgeners << u.referrals
          end
          end
          end

       #  @sixthgeners = @sixthgeners1.flatten 
        @sixthgeners = flatten_scopes(@sixthgeners)
         if @sixthgeners.any?
          @sixthgeners.each do |u| 
          if u.referrals.any?
          @seventhgeners << u.referrals
          end
         end
         end
         #@seventhgeners = @seventhgeners.flatten

        @secondgeners = flatten_scopes(@seventhgeners)
         if @seventhgeners.any?
           @seventhgeners.each do |u| 
           if u.referrals.any?
            @eightgeners << u.referrals
           end
          end
           end 

         #@eightgeners = @eightgeners1.flatten
         end

         #generate all affiliations  of current_user

               def referral_gen(user)
                 referrals = user.referrals
                 return referrals
               end