Detecting change to Knockout view model

Question

Sure this is a very easy question to answer but is there an easy way to determine if any property of a knockout view model has changed?

Answer 1

I like Brett Green's solution. As someone pointed out, the isDirty comparison doesn't work with Date objects. I solved it by extending the subscribe method like this:

    observable.subscribe(function (newValue) {
            observable.isDirty(newValue != observable.originalValue);

            if (newValue instanceof Date) {
                observable.isDirty(newValue.getTime() != observable.originalValue.getTime());
            }
        });