Question

is there a way to automatically sort an observable array when a bound property is changed? I believe in the following example, my view is updated when i add a new person, but can I get the view to refresh and apply my sorting function if one of the person’s age is changed?

person = {
   age: ko.observable();
}

viewModel = {

   people: ko.observableArray([]),

   someSortFunction: function() {
       this.people.sort(function(person1, person2) {
           return person2.age() - person1.age();
       });
    }
}

<div data-bind="foreach: people">
   <span data-bind="text: age"/>
</div>

Answer 1

You can subscribe an observable and act whenever that observable changes:

person.age.subscribe(function (newValue) {
    viewModel.someSortFunction();
});