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, :default => options[:message], :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: If, after the above definition, you then wrote: # # class Page < ActiveRecord::Base # belongs_to :book # # validates_associated :book # end # # this would specify 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 (default is :save, other options :create, :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) options = attr_names.extract_options! validates_with AssociatedValidator, options.merge(:attributes => attr_names) end end end end