Rails: How to limit number of items in has_many association (from Parent)

Question

I would like to limit the number of items in an association. I want to ensure the User doesn\'t have more than X Things. This question was asked before and the solution had th

Answer 1

try this, just like string:

class User < ActiveRecord::Base
  has_many :things, :dependent => :destroy
  validates :things, length: {maximum: 4}
end