Determine if an object property is ko.observable

Question

I'm using KnockoutJS version 2.0.0

If I'm looping through all properties of an object, how can I test whether each property is a ko.observable? Here's what I've tried so far:

    var vm = {         prop: ko.observable(''),         arr: ko.observableArray([]),         func: ko.computed(function(){             return this.prop + " computed";         }, vm)     };      for (var key in vm) {         console.log(key,              vm[key].constructor === ko.observable,              vm[key] instanceof ko.observable);     } 

But so far everything is false.

Answer 1

Knockout includes a function called ko.isObservable(). You can call it like ko.isObservable(vm[key]).

Update from comment:

Here is a function to determine if something is a computed observable:

ko.isComputed = function (instance) {     if ((instance === null) || (instance === undefined) || (instance.__ko_proto__ === undefined)) return false;     if (instance.__ko_proto__ === ko.dependentObservable) return true;     return ko.isComputed(instance.__ko_proto__); // Walk the prototype chain }; 

UPDATE: If you are using KO 2.1+ - then you can use ko.isComputed directly.