Styjun

I am creating an embedded Ruby form and I would like the validation to allow 9 characters before the beginning, but specifcially starting with an 'x', so x12345678@a2z.ie would be a valid email while 12345678@a2z.ie would not be valid.

a2z.ie is the domain and is required.

I have the REGEX code: x+d8+@a2z.ie

The code I have is this:

 <div class="form-group">
 <%= f.label :email %><br />
 <%= f.email_field :email, autofocus: true, autocomplete: "email", :class => 'form-control', :validation => 'x+d8+@a2z.ie' %>
 </div>

I know this code is wrong because it still allows any user's email.

Used an email validator Ruby file instead.

Using Devise as well, if that helps.

In user.rb, add:

validates :email, :presence => true, :email => true

Create a validators folder in models. Then create email_validator.rb in said folder and add this to it:

(app/models/validators/email_validator.rb) :

require 'mail'
class EmailValidator < ActiveModel::EachValidator
 def validate_each(record,attribute,value)
 begin
 m = Mail::Address.new(value)
 # We must check that value contains a domain, the domain has at least
 # one '.' and that value is an email address 
 r = m.domain.present? && m.domain.match('.') && m.address == value
 s = m.domain.present? && m.domain.match('@a2z.ie') && m.address == value

 # Update 2015-Mar-24
 # the :tree method was private and is no longer available.
 # t = m.__send__(:tree)
 # We need to dig into treetop
 # A valid domain must have dot_atom_text elements size > 1
 # user@localhost is excluded
 # treetop must respond to domain
 # We exclude valid email values like <user@localhost.com>
 # Hence we use m.__send__(tree).domain
 # r &&= (t.domain.dot_atom_text.elements.size > 1)
 rescue
 r = false
 end
 record.errors[attribute] << (options[:message] || "is invalid. Please enter xEMPLOYEENUMBER@a2z.ie, e.g. x12345678@a2z.ie") unless (r && s)
 end
end

Wasn't exactly what I wanted, but is somewhat.

Ref: https://github.com/plataformatec/devise/wiki/How-to:-Use-a-custom-email-validator-with-Devise