vendor/rails/activerecord/lib/active_record/validations.rb
# Validates whether the value of the specified attribute is available in a particular enumerable object.
#
#   class Person < ActiveRecord::Base
#     validates_inclusion_of :gender, :in => %w( m f ), :message => "woah! what are you then!??!!"
#     validates_inclusion_of :age, :in => 0..99
#     validates_inclusion_of :format, :in => %w( jpg gif png ), :message => "extension %s is not included in the list"
#   end
#
# Configuration options:
# * <tt>:in</tt> - An enumerable object of available items.
# * <tt>:message</tt> - Specifies a custom error message (default is: "is not included in the list").
# * <tt>:allow_nil</tt> - If set to true, skips this validation if the attribute is +nil+ (default is +false+).
# * <tt>:allow_blank</tt> - If set to true, skips this validation if the attribute is blank (default is +false+).
# * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
#   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
#   method, proc or string should return or evaluate to a true or false value.
# * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
#   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).  The
#   method, proc or string should return or evaluate to a true or false value.
Validates whether the value of the specified attribute is available in a particular enumerable object.

Configuration options:
:in - An enumerable object of available items.
:message - Specifies a custom error message (default is: "is not included in the list").
: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+).
:if - Specifies a method, proc or string to call to determine if the validation should
occur .  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 .  The
method, proc or string should return or evaluate to a true or false value.
Validates whether the value of the specified attribute is available in a particular enumerable object . Configuration options : : in - An enumerable object of available items . : message - Specifies a custom error message ( default is : " is not included in the list " ) . : 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 + ) . : if - Specifies a method proc or string to call to determine if the validation should occur . 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 . The method proc or string should return or evaluate to a true or false value .
def validates_inclusion_of(*attr_names)
        configuration = { :on => :save }
        configuration.update(attr_names.extract_options!)
        enum = configuration[:in] || configuration[:within]
        raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?")
        validates_each(attr_names, configuration) do |record, attr_name, value|
          unless enum.include?(value)
            record.errors.add(attr_name, :inclusion, :default => configuration[:message], :value => value) 
          end
        end
      end
def validates_inclusion_of ( * attr_names ) configuration = { :on => :save } configuration . update ( attr_names . extract_options! ) enum = configuration [ :in ] || configuration [ :within ] raise ( ArgumentError , "An object with the method include? is required must be supplied as the :in option of the configuration hash" ) unless enum . respond_to? ( "include?" ) validates_each ( attr_names , configuration ) do | record , attr_name , value | unless enum . include? ( value ) record . errors . add ( attr_name , :inclusion , :default => configuration [ :message ] , :value => value ) end end end
Validates whether the value of the specified attribute is available in a particular enumerable object.
Validates whether the value of the specified attribute is available in a particular enumerable object .
attr_names