Empty required fields don't show an error

When working with HTML custom elements (<tags>), native form validation—including the required attribute—won’t function automatically. The browser’s form validation system is built to work with standard HTML form elements, such as <input>, <textarea>, and <select>. Instead of using a hidden class to conceal the <input> or <select> elements, we can employ a subtle trick to keep the input element present but invisible. This allows us to benefit from the native required validation while maintaining the use of custom elements.

It will be included in release 1.2.22.