vdom messing with widgets

index.js

var diff = require("virtual-dom").diff
var patch = require("virtual-dom").patch
var h = require("virtual-dom").h
//var _ = require("lodash");

var createElement = require("virtual-dom").create

var OddCounterWidget = function(prefix) {this.prefix = prefix;};
OddCounterWidget.prototype.type = "Widget"
OddCounterWidget.prototype.count = 1
OddCounterWidget.prototype.init = function() {
  // With widgets, you can use any method you would like to generate the DOM Elements.
  // We could get the same result using:
  // return createElement(h("div", "Count is: " + this.count))
  console.log('init', this.prefix, this.count);
  var divElem = document.createElement("div")
  var textElem = document.createTextNode("Count is: " + this.count)
  divElem.appendChild(textElem)
  return divElem
}

OddCounterWidget.prototype.update = function(previous, domNode) {
  this.count = previous.count + 1
  console.log('update', this.prefix, this.count);  
  // Only re-render if the current count is odd
  if (this.count %2 ) {
    // Returning a new element from widget#update
    // will replace the previous node
    return this.init()
  }
  return null
}

OddCounterWidget.prototype.destroy = function(domNode) {
  // While you can do any cleanup you would like here,
  // we don't really have to do anything in this case.
  // Instead, we'll log the current count
  console.log('destroy', this.prefix, this.count)
}

var tree1 = [new OddCounterWidget('A0'), new OddCounterWidget('A1'), new OddCounterWidget('A2'), new OddCounterWidget('A3')]
var tree2 = _.shuffle(tree1)

var myCounter = tree1
var currentNode = myCounter
var rootNode = createElement(currentNode)

// A simple function to diff your widgets, and patch the dom
var update = function(nextNode) {
  var patches = diff(currentNode, nextNode)
  rootNode = patch(rootNode, patches)
  currentNode = nextNode
}

var alt = false
document.body.appendChild(rootNode)
setInterval(function(){
  var tree;
  if (alt) {
    //tree = h('div', [(alt ? new OddCounterWidget() : 'no')]);
    tree = tree1; //h('div', [new OddCounterWidget('a'), new OddCounterWidget('d')]);

  } else {
    tree = tree2 //h('div', [new OddCounterWidget('b'), new OddCounterWidget('c')]);
  }
  update(tree);
  alt = !alt;
}, 1000)