JSFiddle - React, Tailwind, and code Playground

by EstSiim

HTML

<p>Age:
    <input data-bind="value:age" />
</p>
<p>Age has been changed: <span data-bind="text:ageChangeCount"></span> times</p>

JavaScript

function viewModel() {

    var self = this;
   
    self.age = ko.observable(10).extend({
        notify: 'always'
    }), 
        
    self.ageChangeCount = ko.observable(0),
        
    self.age.subscribe(function (val) {
        console.log('Someone has changed age');
        self.ageChangeCount(self.ageChangeCount() + 1);
    });

};

ko.applyBindings(new viewModel());