module ActiveModel module Validations module ClassMethods # Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression # provided. # # class Person < ActiveRecord::Base # validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create # end # # Note: use \A and \Z to match the start and end of the string, ^ and $ match the start/end of a line. # # A regular expression must be provided or else an exception will be raised. # # Configuration options: # * message - A custom error message (default is: "is invalid") # * allow_nil - If set to true, skips this validation if the attribute is null (default is: false) # * allow_blank - If set to true, skips this validation if the attribute is blank (default is: false) # * with - The regular expression used to validate the format with (note: must be supplied!) # * 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. def validates_format_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:invalid], :on => :save, :with => nil } configuration.update(attr_names.extract_options!) raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp) validates_each(attr_names, configuration) do |record, attr_name, value| record.errors.add(attr_name, configuration[:message]) unless value.to_s =~ configuration[:with] end end end end end