You can create a custom binding attrIf which will check the value of a specific observable boolean before add or not the attributes. See this example:
ko.bindingHandlers.attrIf = {
update: function (element, valueAccessor, allBindingsAccessor) {
var h = ko.utils.unwrapObservable(valueAccessor());
var show = ko.utils.unwrapObservable(h._if);
if (show) {
ko.bindingHandlers.attr.update(element, valueAccessor, allBindingsAccessor);
}
else {
for (var k in h) {
if (h.hasOwnProperty(k) && k.indexOf("_") !== 0) {
$(element).removeAttr(k);
}
}
}
}
};
