Can computed be an observable too in KnockoutJS

Question

I have first name and last name as an observable, username is computed. Is it possible to make username observable too ?

Answer 1

A computed in Knockout is already a type of observable. If what you want to be able to do is set the value of a computed then you can do so using the read and write properties.

Here's a very crude example of setting the first and last name:

var fn = ko.observable("Jimbo");
var ln = ko.observable("Jangles");

var vm = {
    myComputed : ko.computed({
        read: function () { return fn() + " " + ln(); },
        write: function (value) {
            var pieces = value.split(" ");
            fn(pieces[0]);
            ln(pieces[pieces.length -1]);
        }
    })
};

Here's a working example:http://jsfiddle.net/xxkLs0p8/