Subscribe to observable array for new or removed entry only

Question

So yes I can subscribe to an observable array:

vm.myArray = ko.observableArray();
vm.myArray.subscribe(function(newVal){...});

The problem

Answer 1

In order to only detect push() and remove() events, and not moving items, I put a wrapper around these observable array functions.

var trackPush = function(array) {
    var push = array.push;
    return function() {
        console.log(arguments[0]);
        push.apply(this,arguments);
    }
}
var list = ko.observableArray();
list.push = trackPush(list);

The original push function is stored in a closure, then is overlayed with a wrapper that allows me do do anything I want with the pushed item before, or after, it is pushed onto the array.

Similar pattern for remove().