Question

I created a callback when creating a new Client object instead of using the validates_uniqueness_of validation method because:

• I want to find the Client that already exists
• Add the existing Client details to my base error message

My question: is there a more elegant way of achieving this than my solution below?

I have the following model:

class Client < ActiveRecord::Base
  before_validation_on_create :prevent_duplicate_clients

  private
    def prevent_duplicate_clients
      client = self.class.find(:all, :conditions => ["first_name = ? AND middle_name = ? AND last_name = ? AND date_of_birth = ?", self.first_name, self.middle_name, self.last_name, self.date_of_birth])

      if client.size >= 1
        self.errors.add(:base, "Client exists as #{client.first.name}")
        false
      end
    end
end

NB:

• Rails v2.3.5

Answer 1

You shouldn’t put validation code in the before_validation callbacks. Change before_validation_on_create :prevent_duplicate_clients to validate :prevent_duplicate_clients