Apply validator even if matching data attribute is empty or 0

[i7an]

Html:

<input type="text" data-pizza="0" />

Js:

$form.validator({
    custom: {
        pizza: function($el) {
            return true;
        }
    },
    errors: {
        pizza: '[Pizza] Error'
    }
});

This validator wont be applied because js treats 0 as falsy.

[lypwig]

Yes! I just need it!
I think this feature is interesting, because some validations doesn't need any argument. In this case, the html line will be refined, ie <input type="text" data-foo />, instead of <input type="text" data-foo="fake-value-to-make-it-work" />.