Question

I have two models Customer and Referal. Both have an email attribute. Referal belongs to Customer and Customer has_many Referals.

When I create/update a Referal I want to check that email on the Referal does not equal email on the Customer (parent) object.

Here’s my Referal object: (cut out irrelevant stuff)

class Referal < ActiveRecord::Base
  belongs_to :user
  belongs_to :customer

  validates :name, :presence => true
  validates :email, :presence => true
  validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create
  validate :email_cannot_equal_referers

  def email_cannot_equal_referers
    if email == customer.email
      errors.add(:email, "can't be the same as referer's")
    end
  end
end

Here’s Customer:

class Customer < ActiveRecord::Base
  has_many :referals 
  validates_presence_of :name, :email
  validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :allow_blank => true
end

When I try to save Referal I get “undefined method `email’ for nil:NilClass”, which refers to customer.email as it works when I put email==email.
At this point Referal is not written to the database yet, though customer_id seems to be set, as I can use it in the error message (with .to_s), but it doesn’t work either to use this to search for Customer object using Customer.find(customer_id). (Couldn’t find Customer without an ID)

For completeness here is the controller bit that calls the save method on Referal:

@refer=Referal.new
@refer.name=params[:Name2]
@refer.email=params[:Email2]
@refer.message=params[:Message]
@customer.referals << @refer
if @refer.save
  CustomerMailer.refer(@refer).deliver
  CustomerMailer.refer_thanks(@refer).deliver
else
  render 'new_refer'
end

Would greatly appreciate pointers to make this work!
Thanks

Answer 1

If the customer already exists in the db the validation you have should work.

If you are trying to create the customer and the referrals at the same time I would use the accepts_nested_attributes_for method through the customer model. I think you might have to add a validation in the customer model that iterates through the referrals.

class Customer < ActiveRecord::Base
    has_many :referals
    accepts_nested_attributes_for :referals
end

then in your controller

@customer.referals << @refer
if @customer.save
   @customer.referals.each do |r|
      CustomerMailer.refer(r).deliver
      CustomerMailer.refer_thanks(r).deliver
   end
 end