How to get all invalid elements using jQuery Validator?

This is how I wanted to solve it:

$form.validate().settings.invalidHandler = function (form, validator) {
    debugger;
    var errors = validator.numberOfInvalids();
    debugger;
    if (errors) {
        validator.errorList[0].element.focus();
        for (var invObj in validator.errorList) {
            //do something for each invalid object
        }
    }
};

Where $form is <form> object that have some inputs to validate inside.

I thought that it will be called for each invalid object after I call $form.validate() or $form.valid(). In fact, it isn't called at all. Do you know some better ways to accomplish it?