lib/active_model/validations/exclusion.rb
# frozen_string_literal: true require "active_model/validations/clusivity" module ActiveModel module Validations class ExclusionValidator < EachValidator # :nodoc: include Clusivity def validate_each(record, attribute, value) if include?(record, value) record.errors.add(attribute, :exclusion, **options.except(:in, :within).merge!(value: value)) end 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: ->(person) { [person.username, person.first_name] }, # message: 'should not be the same as your username or first name' # validates_exclusion_of :karma, in: :reserved_karmas # end # # Configuration options: # * <tt>:in</tt> - An enumerable object of items that the value shouldn't # be part of. This can be supplied as a proc, lambda, or symbol which returns an # enumerable. If the enumerable is a numerical, time, or datetime range the test # is performed with <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>. When # using a proc or lambda the instance under validation is passed as an argument. # * <tt>:within</tt> - A synonym(or alias) for <tt>:in</tt> # <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>. # * <tt>:message</tt> - Specifies a custom error message (default is: "is # reserved"). # # There is also a list of default options supported by every validator: # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+. # See ActiveModel::Validations::ClassMethods#validates for more information. def validates_exclusion_of(*attr_names) validates_with ExclusionValidator, _merge_attributes(attr_names) end end end end