Knockout extender: cache

cache.js

ko.extenders.cache1 = function (target) {
    target.cached = ko.observable(target.peek());
    target.cache = function () {
        target.cached(target());
    };
    return target;
};

var x = ko.observable(1).extend({ cache1: {} });
x(2);
console.log(x());
console.log(x.cached());
x.cache();
console.log(x.cached());

ko.extenders.cache2 = function (target) {
    var cached = ko.observable(target.peek());
    var result = ko.computed({
        read: cached,
        write: function (value) {
            target(value);
        }
    });
    result.current = target;
    result.cache = function () {
        cached(target());
    };
    return result;
};

var y = ko.observable(3).extend({ cache2: {} });
y(4);
console.log(y.current());
console.log(y());
y.cache();
console.log(y());

output.txt

2
1
2
4
3
4