knockout.js - knockoutjs child object trigger change in parent computed -

is there easier way parent object's 'subscribe' fire changes of lower level observables?

the following code , sample fiddle working, requires me duplicate masteroptions in optionset. smaller version manageable, masteroptions set can become quite large make maintenance of both masteroptions , optionset difficult , error-prone.

sample jsfiddle found here: fiddle

html:

<div>     setting1a: <input data-bind="value: masteroptions.group1.setting1a" /><br />     setting1b: <input data-bind="value: masteroptions.group1.setting1b" /><br />     setting2a: <input data-bind="value: masteroptions.group2.setting2a" /><br />     setting2b: <input data-bind="value: masteroptions.group2.setting2b" /><br />     <br />     span1: <span data-bind="text: ko.tojson(optionset)"></span><br/>     <br />     span2: <span id="myspan"></span> </div> 

script:

var masteroptions = {     group1: {         setting1a: ko.observable("value1a"),         setting1b: ko.observable("value1b")     },     group2: {         setting2a: ko.observable("value2a"),         setting2b: ko.observable("value2b")     } }; var optionset = ko.computed(function () {     return {         group1: {             setting1a: masteroptions.group1.setting1a(),             setting1b: masteroptions.group1.setting1b()         },         group2: {             setting2a: masteroptions.group2.setting2a(),             setting2b: masteroptions.group2.setting2b()         }     }; }); optionset.subscribe(function () {     //alert("make magic happen.");     $("#myspan").html($("#myspan").html() + "more magic. "); }); var viewmodel = function () {     return {         masteroptions: masteroptions,         optionset: optionset     }; };  ko.applybindings(new viewmodel()); 

i rather not have recreate masteroptions optionset, don't see how can have single subscribe fire when of lower level observables change.

calling ko.tojs on masteroptions inside computed trick:

var optionset = ko.computed(function () {     return ko.tojs(masteroptions); }); 

[ jsfiddle ]

this creates dependency on every observable in structure. observables added included dependencies.

however if want subscribe directly masteroptions and/or need more flexibility might consider using handy little plugin wrote myself pretty same purposes:

https://github.com/ziadj/knockoutjs-reactor