Contents

# Allows to check if the value of a specific attribute is a valid IMEI address.
#
# @example Validate that the device IMEI address is valid.
#   class Device << ActiveRecord::Base
#     attr_accessor :imei
#     validates :imei, imei: true
#   end
class ImeiValidator < ActiveModel::EachValidator
  # Checks if an attribute value is a valid IMEI address.
  #
  # @param [Object] record object to validate
  # @param [String] attribute name of the object attribute to validate
  # @param [Object] value attribute value
  def validate_each(record, attribute, value)
    allow_blank = options[:allow_blank] || false
    return if allow_blank && value.blank?

    unless valid?(value.to_s, options)
      record.errors[attribute] << (options[:message] || I18n.t('errors.messages.imei'))
    end
  end

  def self.validate_format(imei_number)
    !!(imei_number =~ /\A[\d\.\:\-\s]+\z/i) # 356843052637512 or 35-6843052-637512 or 35.6843052.637512
  end

  def self.luhn_valid?(input)
    numbers = input.gsub(/\D/, '').reverse

    sum, i = 0, 0

    numbers.each_char do |ch|
      n = ch.to_i
      n *= 2 if i.odd?
      n = 1 + (n - 10) if n >= 10

      sum += n
      i   += 1
    end

    (sum % 10).zero?
  end

  private

  def valid?(imei, options)
    self.class.validate_format(imei) \
      && self.class.luhn_valid?(imei)
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
missing_validators-1.0.1	lib/missing_validators/validators/imei_validator.rb
missing_validators-0.9.1	lib/missing_validators/validators/imei_validator.rb
missing_validators-0.9	lib/missing_validators/validators/imei_validator.rb