Ruby on Rails single table inheritance sample form

Question

i'm a super newbie in rails and i need to see a sample code on how to implement Single table iheritance, i have a model called Listing as a super class, and i have subclasses LawFirms and Paralegal, these all extend the Listing model, now i need to be able to create a new listing, but when i am creating i need the form to have an option to select either Law Firm or Paralegal, when Law Firm option is selected, it should show a form for creating a LawFirm object which is different from the Paralegal Object because a law firm has advocates and a paralegal wont have advocates.

So far my models look like this

class Listing < ActiveRecord::Base end

class LawFirm < Listing has_many :advocates end

class Paralegal < Listing end

How do i create the controller? and the form?

Answer 1

I'm not sure that inheritance is the right solution for this. Inheritance is used for an is-a relationship. For example, a Nissan is a car so Nissan would inherit from the car class. You might be better off having LawFrim or Paralegal as objects in a Listing using a nested resource in rails. You could then add some checks in the controller to make sure it only has one or the other of those objects.