Email Validation

[Andy]

Hi all,

I am using the asp:RegularExpressionValidator for telerik:RadTextBox to validate email address as following link
http://demos.telerik.com/aspnet-ajax/input/examples/common/validation/defaultcs.aspx

But it is wrong when user input space at the front or at the end of the email address.
Are there any ways to trim it?

Thanks.

Andy.

[Vasil]

Hi Andy,

Yes, you could trim the string on OnValueChanging event of the text box just before the validation.

Here is an example:

<script type="text/javascript">
  function TrimIt(sender, args)
  {
    var value = args.get_newValue();
    var trimmed = value.replace(/^\s+|\s+$/g, '');
    args.set_newValue(trimmed);
  }
</script>
<div>
  <telerik:RadTextBox ID="Radtextbox2" runat="server">
    <ClientEvents OnValueChanging="TrimIt" />
  </telerik:RadTextBox>
  <asp:RegularExpressionValidator ID="emailValidator" runat="server" Display="Dynamic"
    ErrorMessage="Please, enter valid e-mail address." ValidationExpression="^[\w\.\-]+@[a-zA-Z0-9\-]+(\.[a-zA-Z0-9\-]{1,})*(\.[a-zA-Z]{2,3}){1,2}$"
    ControlToValidate="Radtextbox2">
  </asp:RegularExpressionValidator>
  <asp:RequiredFieldValidator ID="Requiredfieldvalidator1" runat="server" Display="Dynamic"
    ControlToValidate="Radtextbox2" ErrorMessage="Please, enter an e-mail!" />
</div>

You could also see this resources for more information:
http://www.telerik.com/help/aspnet-ajax/input-client-side-onvaluechanging.html
http://developer.loftdigital.com/blog/trim-a-string-in-javascript

I hope this helps.

Greetings,
Vasil
the Telerik team

[Andy]

That's great.
Thanks Vasil.

Andy.

[Neil]

For anyone else looking for an email regex, note that the one posted by Vasil doesn't allow some characters that are valid before the @ symbol e.g. apostrophe

 

Better to take from Kendo UI source code? https://github.com/telerik/kendo-ui-core/blob/master/src/kendo.validator.js:

^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$