module ActiveModel
module Validations
class LengthValidator < EachValidator
OPTIONS = [ :is, :within, :in, :minimum, :maximum ].freeze
MESSAGES = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }.freeze
CHECKS = { :is => :==, :minimum => :>=, :maximum => :<= }.freeze
DEFAULT_TOKENIZER = lambda { |value| value.split(//) }
attr_reader :type
def initialize(options)
options[:tokenizer] ||= DEFAULT_TOKENIZER
super
@type = (OPTIONS & options.keys).first
end
def check_validity!
ensure_one_range_option!
ensure_argument_types!
end
def validate_each(record, attribute, value)
checks = options.slice(:minimum, :maximum, :is)
value = options[:tokenizer].call(value) if value.kind_of?(String)
if [:within, :in].include?(type)
range = options[type]
checks[:minimum], checks[:maximum] = range.begin, range.end
checks[:maximum] -= 1 if range.exclude_end?
end
checks.each do |key, check_value|
custom_message = options[:message] || options[MESSAGES[key]]
validity_check = CHECKS[key]
valid_value = if key == :maximum
value.nil? || value.size.send(validity_check, check_value)
else
value && value.size.send(validity_check, check_value)
end
record.errors.add(attribute, MESSAGES[key], :default => custom_message, :count => check_value) unless valid_value
end
end
protected
def ensure_one_range_option! #:nodoc:
range_options = 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
end
def ensure_argument_types! #:nodoc:
value = options[type]
case type
when :within, :in
raise ArgumentError, ":#{type} must be a Range" unless value.is_a?(Range)
when :is, :minimum, :maximum
raise ArgumentError, ":#{type} must be a nonnegative Integer" unless value.is_a?(Integer) && value >= 0
end
end
end
module ClassMethods
# 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 {{count}} 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 :fav_bra_size, :minimum => 1, :too_short => "please enter at least {{count}} character"
# validates_length_of :smurf_leader, :is => 4, :message => "papa is spelled with {{count}} characters... don't play me."
# validates_length_of :essay, :minimum => 100, :too_short => "Your essay must be at least {{count}} 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(*attr_names)
options = { :tokenizer => DEFAULT_TOKENIZER }
options.update(attr_names.extract_options!)
validates_with LengthValidator, options.merge(:attributes => attr_names, :type => type)
end
alias_method :validates_size_of, :validates_length_of
end
end
end