skyhKnockout promise extender 
Knockout extender for handling promises.
Installation
npm install knockout-promise-extenderAdding to knockout
var ko = require('knockout');
var promiseExtenderFactory = require('knockout-promise-extender');
ko.extenders.promise = promiseExtenderFactory(ko);Usage
var x = ko.observable().extend({promise: true});
console.log(
x, // observable
x() // PromiseState
);
console.log(
x().pending, // true
x().resolved, // false
x().rejected, // false
x().value // undefined
);
x(Promise.resolve('some value'));
console.log(
x().pending, // true, because Promise.resolve is async
x().resolved, // false
x().rejected, // false
x().value // undefined
);
setTimeout(function () {
console.log(
x().pending, // false
x().resolved, // true
x().rejected, // false
x().value // "some value"
);
}, 0);Usage in bindings
<div class="promised-model-view">
<!-- ko if: x().pending -->
<span class="wait-message">
Loading data...
</span>
<!-- /ko -->
<!-- ko if: x().resolved -->
<span class="data" data-bind="text: x().value"></span>
<!-- /ko -->
<!-- ko if: x().rejected -->
<span class="error-message">
Something went wrong. Error is
<span data-bind="text: x().value"></span>
</span>
<!-- /ko -->
</div>