# File lib/rails/active_record_ext.rb, line 65
 65:       def validates_length_of(*attrs)
 66:         # Merge given options with defaults.
 67:         options = {
 68:           :too_long     => ActiveRecord::Errors.default_error_messages[:too_long],
 69:           :too_short    => ActiveRecord::Errors.default_error_messages[:too_short],
 70:           :wrong_length => ActiveRecord::Errors.default_error_messages[:wrong_length]
 71:         }.merge(DEFAULT_VALIDATION_OPTIONS)
 72:         options.update(attrs.extract_options!.symbolize_keys)
 73: 
 74:         # Ensure that one and only one range option is specified.
 75:         range_options = ALL_RANGE_OPTIONS & options.keys
 76:         case range_options.size
 77:           when 0
 78:             raise ArgumentError, 'Range unspecified.  Specify the :within, :maximum, :minimum, or :is option.'
 79:           when 1
 80:             # Valid number of options; do nothing.
 81:           else
 82:             raise ArgumentError, 'Too many range options specified.  Choose only one.'
 83:         end
 84: 
 85:         # Get range option and value.
 86:         option = range_options.first
 87:         option_value = options[range_options.first]
 88: 
 89:         myfirst = true
 90: 
 91:         case option
 92:           when :within, :in
 93:             raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range)
 94: 
 95:             validates_each(attrs, options) do |record, attr, value|
 96: 
 97:               if myfirst == true
 98:                 myfirst = false
 99:                 too_short = options[:too_short][options[:too_short].tr('[   ]', '_').to_sym] % option_value.begin
100:                 too_long  = options[:too_long][options[:too_long].tr('[   ]', '_').to_sym] % option_value.end
101:               end
102: 
103:               if value.nil? or value.split(//).size < option_value.begin
104:                 record.errors.add(attr, too_short)
105:               elsif value.split(//).size > option_value.end
106:                 record.errors.add(attr, too_long)
107:               end
108:             end
109:           when :is, :minimum, :maximum
110:             raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0
111: 
112:             # Declare different validations per option.
113:             validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" }
114:             message_options = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }
115: 
116:             message = (options[:message] || options[message_options[option]]) % option_value
117: 
118:             validates_each(attrs, options) do |record, attr, value|
119:               if value.kind_of?(String)
120:                 record.errors.add(attr, message) unless !value.nil? and value.split(//).size.method(validity_checks[option])[option_value]
121:               else
122:                 record.errors.add(attr, message) unless !value.nil? and value.size.method(validity_checks[option])[option_value]
123:               end
124:             end
125:         end
126:       end