require 'active_support/core_ext/range' module ActiveModel # == Active Model Exclusion Validator module Validations class ExclusionValidator < EachValidator ERROR_MESSAGE = "An object with the method #include? or a proc or lambda is required, " << "and must be supplied as the :in option of the configuration hash" def check_validity! unless [:include?, :call].any? { |method| options[:in].respond_to?(method) } raise ArgumentError, ERROR_MESSAGE end end def validate_each(record, attribute, value) delimiter = options[:in] exclusions = delimiter.respond_to?(:call) ? delimiter.call(record) : delimiter if exclusions.send(inclusion_method(exclusions), value) record.errors.add(attribute, :exclusion, options.except(:in).merge!(:value => value)) end end private # In Ruby 1.9 Range#include? on non-numeric ranges checks all possible values in the # range for equality, so it may be slow for large ranges. The new Range#cover? # uses the previous logic of comparing a value with the range endpoints. def inclusion_method(enumerable) enumerable.is_a?(Range) ? :cover? : :include? end end module HelperMethods # Validates that the value of the specified attribute is not in a particular enumerable object. # # class Person < ActiveRecord::Base # validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here" # validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60" # validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension %{value} is not allowed" # validates_exclusion_of :password, :in => lambda { |p| [p.username, p.first_name] }, :message => "should not be the same as your username or first name" # end # # Configuration options: # * :in - An enumerable object of items that the value shouldn't be part of. # This can be supplied as a proc or lambda which returns an enumerable. If the enumerable # is a range the test is performed with Range#cover? # (backported in Active Support for 1.8), otherwise with include?. # * :message - Specifies a custom error message (default is: "is reserved"). # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * :allow_blank - If set to true, skips this validation if the attribute is blank (default is +false+). # * :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. # * :strict - Specifies whether validation should be strict. # See ActiveModel::Validation#validates! for more information def validates_exclusion_of(*attr_names) validates_with ExclusionValidator, _merge_attributes(attr_names) end end end end