JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgithub.com/SteveSanderson/knockout-es5/master/dist/knockout-es5.min.js"></script>
<span data-bind="text: showViewModelData"></span>
<button data-bind="click: toggleViewModel">Click</button>

JavaScript

var ViewModel = function(){
  var self = this;

  self.showViewModelData = ko.observable(false);

  self.toggleViewModel = function(){
    self.showViewModelData = !self.showViewModelData;
  }
  ko.track(self);
};
ko.applyBindings(new ViewModel());