Validation in HTML5. :invalid classe after submit

Question

I\'m building a form and I want to use the :invalid selector to give the \"required\" input fields a red border if the user presses submit without filling them, but

Answer 1

No there is nothing out of the box.

Mozilla has its own pseudoclass for something very similiar called ':-moz-ui-invalid'. If you want to achieve something like this, you have to use the constraint validation DOM-API:

if(document.addEventListener){
    document.addEventListener('invalid', function(e){
        e.target.className += ' invalid';
    }, true);
}

You can also use webshims lib polyfill, which will not only polyfill incapable browsers, but also adds something similiar like -moz-ui-invalid to all browser (.form-ui-invalid).