require 'active_support/core_ext/range.rb'
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)
exclusions = options[:in].respond_to?(:call) ? options[:in].call(record) : options[:in]
if exclusions.send(inclusion_method(exclusions, options[:use_include]), value)
record.errors.add(attribute, :exclusion, options.except(:in, :use_include).merge!(:value => value))
end
rescue NoMethodError
raise ArgumentError, "Exclusion validation for :#{attribute} in #{record.class.name}: #{ERROR_MESSAGE}"
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, use_include = nil)
!use_include && 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.
# * :use_include - If set to true and the enumerable in :in option is a range,
# it will explicitly use Range#include? to perform the test. Otherwise Range#cover?
# will be used to perform the test for performance reason.
# (Range#cover? was backported in Active Support for 1.8.x)
# * :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.
def validates_exclusion_of(*attr_names)
validates_with ExclusionValidator, _merge_attributes(attr_names)
end
end
end
end