Javascript change event on input element fires on only losing focus

Question

I have an input element and I want to keep checking the length of the contents and whenever the length becomes equal to a particular size, I want to enable the submit button

Answer 1

Here is another solution I develop for the same problem. However I use many input boxes so I keep old value as an user-defined attribute of the elements itself: "data-value". Using jQuery it is so easy to manage.

        $(document).delegate('.filterBox', 'keyup', { self: this }, function (e) {
            var self = e.data.self;

            if (e.keyCode == 13) {
                e.preventDefault();
                $(this).attr('data-value', $(this).val());
                self.filterBy(this, true)
            }
            else if (e.keyCode == 27) {
                $(this).val('');
                $(this).attr('data-value', '');
                self.filterBy(this, true)
            }
            else {
                if ($(this).attr('data-value') != $(this).val()) {
                    $(this).attr('data-value', $(this).val());
                    self.filterBy(this);
                }
            }
        });

here is, I used 5-6 input boxes have class 'filterBox', I make filterBy method run only if data-value is different than its own value.