ValidatesExistence
==================

This plugin adds a new validates_existence_of method to ActiveRecord::Base.

The validates_existence_of validator checks that a foreign key in a belongs_to
association points to an exisiting record. If :allow_nil => true, then the key
itself may be nil. A non-nil key requires that the foreign object must exist.
Works with polymorphic belongs_to.

The default error message is "does not exist".

Example
=======

  class Person < ActiveRecord::Base
    belongs_to :address
    validates_existence_of :address
  end


Copyright (c) 2007 Josh Susser, released under the MIT license
