Server side field validation can make the filling process of the form faster. It will show the incorrect form values on the fly. Remote validation must be done only in case when it is impossible to produce it on client side.
Focusing form field in tabpanel
Focusing one of the form fields after rendering the panel or changing the active tab with form items will make the filling process of the form faster. Users will not need to click on the appropriate field to begin the typing. The focusing feature was implemented as plugin.
Google reCAPTCHA, Version 2 field
reCAPTCHA protects internet users from spam and abuse wherever they go. Here is a ‘CaptchaField’ class which you can set to validate form. It changes the validation of the field, so you can bind appropriate buttons to the form.