Rails replace ApplicationRecord instance on save

Question

A have a Contact model with email uniqueness that can be soft deleted.

I want that when someone tries to create a contact with an e-mail taken by some soft_deleted contact, this new instance becomes the soft deleted record.

An example to make it clear

contact = Contact.new(email: 'sameemail@gmail.com')
contact.save # this got id = 1
contact.soft_destroy

# I expect contact2 to have id 1
contact2 = Contact.new(email: 'sameemail@gmail.com')
contact2.save

# I was able to do it with create

PS: I'm actually creating contacts as nested_attributes, so if I could do this spooky save as part of this, it would be great.

Event has_many Invites has_one Contact

The closest I got was this:

class Event < ApplicationRecord
  accepts_nested_attributes_for :invites

  before_save :restore_contacts

  def restore_contacts
    invites.each do |invite|     
      restorable_contact = Contact.find_by_email invite.contact.email
      invite.contact = restorable_contact if restorable_contact
    end
  end
end

But it raises the validation error on the contact before this method is run :(

Answer 1

As you say, to solve the first part you have to do (maybe not the best choice, but I'm trying to explain the logic):

In your Contact model

# app/models/contact.rb
class Contact < ApplicationRecord 
  validates :email, uniqueness: true  
  ...
  def restore
    self.update_attribute deleted_by_user_at, nil
    # other actions ...
  end
  ...
end

Then, you can do the following:

contact = Contact.find_or_initialize_by email: "some@email.com"

if contact.persisted?
  # email exists as Contact on DB
  # it needs some extra validation
  if contact.deleted_by_user_at.nil?
    # email is already in use
  else
    # contact was soft deleted
    contact.restore
  end
else
  # email is free to use
  contact.save
end

If you really need use nested_attributes you would have to change/add code, but logic will be the same