Question

This code works fine with jQuery 1.5.1, but when I use jQuery 1.6.0 it changes the value of the checkbox after click, but it does not add the class ‘done’ to the element.

$("input:checkbox").live('change', function(eve) {
    eve.preventDefault();
    var el =  this.id ;
    var done =  this.done ;
    if( $(this).attr("checked") == true ) {
        $('#item-'+el).find(".text").addClass('done');
        //return false;
    }
    if( $(this).attr("checked") == false ) {
        $('#item-'+el).find(".text").removeClass('done');
        //return false;
    }

    $.post('taskDone.php', {
        id: this.id,
        value: $(this).attr("checked") ? 1 : 0
    }, function(data) {});
});

Answer 1

prior to 1.6

$(this).attr("checked") is inconsistent, as it can be a boolean or it can be a string

jQuery says something like: attribute is what’s inside a property. so, it stopped sending you a bool value and it’s sending you a string value instead.

if you change all

$(this).attr("checked")

to

$(this).prop("checked")

you will have no problems

---

from jQuery Documentation

For example, consider a DOM element defined by the HTML markup <input type="checkbox" checked="checked" />, and assume it is in a JavaScript variable named elem:

elem.checked                       true (Boolean)
$(elem).prop("checked")            true (Boolean)
elem.getAttribute("checked")       "checked" (String)
$(elem).attr("checked")(1.6+)      "checked" (String)
$(elem).attr("checked")(pre-1.6)   true (Boolean)