Question

1. New on HTML5 there’s an “invalid” event, to which you can add a listener:

   document.addEventListener('invalid', function(e){
      var element = $(e.target);
      element.addClass("invalid");
      element.parent().addClass("invalid");
   }, true);
   

   Please note, this event just works when submitting the form… If I style the input input:invalid { background: red }, the style is applied when the user starts typing and his input is not valid. Is that event only fired on submit? I tried adding the listener to the inputs themselves instead of the document and it didn’t work.

2. I add a listener in order to apply a style to the input’s parent… Now, when the user corrects it, it’s valid again… I know there’s not a “valid” event, so, how can I accomplish it?

---

Ok, so here’s a fiddle –> http://jsfiddle.net/Osoascam/ceArQ/7/
The invalid listener seems to be only fired on submit… I just wanted to know whether there’s a way to add a handler just like there is for focus. See that if you type a

Thanks in advance,

Óscar

Answer 1

You should use the :invalid pseudo selector and the input or the change event, to solve your problem.

$(document).bind('change', function(e){
    if( $(e.target).is(':invalid') ){
        $(e.target).parent().addClass('invalid');
    } else {
        $(e.target).parent().removeClass('invalid');
    }
});

Here is a simple fiddle http://jsfiddle.net/trixta/YndYx/.

If you want to remove the error class as soon as possible you should add the error class on change and remove it on the input event (Note: input event is much better than here suggested keyup, simply because it also is triggered on paste etc., but it only works with input elements, not textarea.)

And here is a fiddle using a mixture of input and change event:
http://jsfiddle.net/trixta/jkQEX/

And if you want to have this cross browser you can simply use webshims lib to polyfill. Here is a x-browser example:
http://jsfiddle.net/trixta/RN8PA/