module ActiveModel # == Active Model Length Validator module Validations class LengthValidator < EachValidator MESSAGES = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }.freeze CHECKS = { :is => :==, :minimum => :>=, :maximum => :<= }.freeze DEFAULT_TOKENIZER = lambda { |value| value.split(//) } RESERVED_OPTIONS = [:minimum, :maximum, :within, :is, :tokenizer, :too_short, :too_long] def initialize(options) if range = (options.delete(:in) || options.delete(:within)) raise ArgumentError, ":in and :within must be a Range" unless range.is_a?(Range) options[:minimum], options[:maximum] = range.begin, range.end options[:maximum] -= 1 if range.exclude_end? end super end def check_validity! keys = CHECKS.keys & options.keys if keys.empty? raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.' end keys.each do |key| value = options[key] unless value.is_a?(Integer) && value >= 0 raise ArgumentError, ":#{key} must be a nonnegative Integer" end end end def validate_each(record, attribute, value) value = (options[:tokenizer] || DEFAULT_TOKENIZER).call(value) if value.kind_of?(String) CHECKS.each do |key, validity_check| next unless check_value = options[key] value ||= [] if key == :maximum value_length = value.respond_to?(:length) ? value.length : value.to_s.length next if value_length.send(validity_check, check_value) errors_options = options.except(*RESERVED_OPTIONS) errors_options[:count] = check_value default_message = options[MESSAGES[key]] errors_options[:message] ||= default_message if default_message record.errors.add(attribute, MESSAGES[key], errors_options) end end end module HelperMethods # Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time: # # class Person < ActiveRecord::Base # validates_length_of :first_name, :maximum => 30 # validates_length_of :last_name, :maximum => 30, :message => "less than 30 if you don't mind" # validates_length_of :fax, :in => 7..32, :allow_nil => true # validates_length_of :phone, :in => 7..32, :allow_blank => true # validates_length_of :user_name, :within => 6..20, :too_long => "pick a shorter name", :too_short => "pick a longer name" # validates_length_of :zip_code, :minimum => 5, :too_short => "please enter at least 5 characters" # validates_length_of :smurf_leader, :is => 4, :message => "papa is spelled with 4 characters... don't play me." # validates_length_of :essay, :minimum => 100, :too_short => "Your essay must be at least 100 words.", :tokenizer => lambda { |str| str.scan(/\w+/) } # end # # Configuration options: # * :minimum - The minimum size of the attribute. # * :maximum - The maximum size of the attribute. # * :is - The exact size of the attribute. # * :within - A range specifying the minimum and maximum size of the attribute. # * :in - A synonym(or alias) for :within. # * :allow_nil - Attribute may be +nil+; skip validation. # * :allow_blank - Attribute may be blank; skip validation. # * :too_long - The error message if the attribute goes over the maximum (default is: "is too long (maximum is %{count} characters)"). # * :too_short - The error message if the attribute goes under the minimum (default is: "is too short (min is %{count} characters)"). # * :wrong_length - The error message if using the :is method and the attribute is the wrong size (default is: "is the wrong length (should be %{count} characters)"). # * :message - The error message to use for a :minimum, :maximum, or :is violation. An alias of the appropriate too_long/too_short/wrong_length message. # * :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. # * :tokenizer - Specifies how to split up the attribute string. (e.g. :tokenizer => lambda {|str| str.scan(/\w+/)} to # count words as in above example.) # Defaults to lambda{ |value| value.split(//) } which counts individual characters. def validates_length_of(*attr_names) validates_with LengthValidator, _merge_attributes(attr_names) end alias_method :validates_size_of, :validates_length_of end end end