⩰ John Otander

Email Format Validator for Rails

Dec 6, 2013

I made a gem called Email Format that utilizes the validate_each method that’s included in ActiveModel::Validations. It uses the email_regex gem written by Doug Wiegley which “provides a valid email regex that conforms to most valid RFC edges cases (disallows backticks), and allows for a few illegal patterns that are in common use”.

The validator itself is very simple, it simply compares the attribute in question to the EmailRegex::EMAIL_ADDRESS_REGEX like so:

class EmailFormatValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    unless value =~ EmailRegex::EMAIL_ADDRESS_REGEX
      record.errors[attribute] << (options[:message] || "is invalid")

So, you can now do the following to validate your email attributes:

require 'email_format'

class Awesome
  include ActiveModel::Validations
  attr_accessor :email
  validates :email, email_format: true
 awesome = Awesome.new

 awesome.email = "valid@email.com"
 awesome.valid? # => true

 awesome.email = "invalid_email"
 awesome.valid? # => false

See the Github repo