module ActiveRecord module Validations class AssociatedValidator < ActiveModel::EachValidator def validate_each(record, attribute, value) return if (value.is_a?(Array) ? value : [value]).collect{ |r| r.nil? || r.valid? }.all? record.errors.add(attribute, :invalid, options.merge(:value => value)) end end module ClassMethods # Validates whether the associated object or objects are all valid themselves. Works with any kind of association. # # class Book < ActiveRecord::Base # has_many :pages # belongs_to :library # # validates_associated :pages, :library # end # # WARNING: This validation must not be used on both ends of an association. Doing so will lead to a circular dependency and cause infinite recursion. # # NOTE: This validation will not fail if the association hasn't been assigned. If you want to # ensure that the association is both present and guaranteed to be valid, you also need to # use +validates_presence_of+. # # Configuration options: # * :message - A custom error message (default is: "is invalid") # * :on - Specifies when this validation is active. Runs in all # validation contexts by default (+nil+), other options are :create # and :update. # * :if - Specifies a method, proc or string to call to determine if the validation should # occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The # method, proc or string should return or evaluate to a true or false value. # * :unless - Specifies a method, proc or string to call to determine if the validation should # not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The # method, proc or string should return or evaluate to a true or false value. def validates_associated(*attr_names) validates_with AssociatedValidator, _merge_attributes(attr_names) end end end end