module ActiveModel module Validations module ClassMethods ALL_RANGE_OPTIONS = [ :is, :within, :in, :minimum, :maximum ].freeze # 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 (default is :save, other options :create, :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(*attrs) # Merge given options with defaults. options = { :tokenizer => lambda {|value| value.split(//)} } options.update(attrs.extract_options!.symbolize_keys) # Ensure that one and only one range option is specified. range_options = ALL_RANGE_OPTIONS & options.keys case range_options.size when 0 raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.' when 1 # Valid number of options; do nothing. else raise ArgumentError, 'Too many range options specified. Choose only one.' end # Get range option and value. option = range_options.first option_value = options[range_options.first] key = {:is => :wrong_length, :minimum => :too_short, :maximum => :too_long}[option] custom_message = options[:message] || options[key] case option when :within, :in raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range) validates_each(attrs, options) do |record, attr, value| value = options[:tokenizer].call(value) if value.kind_of?(String) min, max = option_value.begin, option_value.end max = max - 1 if option_value.exclude_end? if value.nil? || value.size < min record.errors.add(attr, :too_short, :default => custom_message || options[:too_short], :count => min) elsif value.size > max record.errors.add(attr, :too_long, :default => custom_message || options[:too_long], :count => max) end end when :is, :minimum, :maximum raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0 # Declare different validations per option. validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" } validates_each(attrs, options) do |record, attr, value| value = options[:tokenizer].call(value) if value.kind_of?(String) valid_value = if option == :maximum value.nil? || value.size.send(validity_checks[option], option_value) else value && value.size.send(validity_checks[option], option_value) end record.errors.add(attr, key, :default => custom_message, :count => option_value) unless valid_value end end end alias_method :validates_size_of, :validates_length_of end end end