Validates Existence

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© 2007 Josh Susser, released under the MIT license

NOTE: This description has been extracted from the Plugin README and so the formatting may need updating to make browser friendly