How do I do a parse, lookup, and assign foreign key on a signup page?

Question

Hi, needing some help to just break down the problem.

I have new users who will put in User.Email in a signup process. (I am using Ruby on Rails).

For any given email, I want to parse out the @domain portion.

I then want to find in a different model, Companies, the company_id with the matching column for @domain.

I want to return that instance, and then pass that value into the User.new

I kind of get what needs to happen at the level described, but need some guidance on the next level down.

Answer 1

I'd do something like this

In user.rb

before_validation_on_create :assign_company

def assign_company
  unless self.email.blank?
    self.company = Company.find_by_domain(/@(.+)/.match(self.email))
  end
end

This will call assign_company before validation when a user is created. Here you check to see that the email has been set and then find the company by extracting the domain from the email.

I haven't tested this, so it might not work as is, but it should hopefully point you in the right direction.