Simple virtual-dom algorithm. It has only ~500 lines of code, including very basic idea of virtual-dom algorithm.

npm:

$ npm install simple-virtual-dom --save

or checkout the bundle.js in dist:

<script src="simple-virtual-dom/dist/bundle.js"></script>

var svd = require('simple-virtual-dom')

var el = svd.el
var diff = svd.diff
var patch = svd.patch

// 1. use `el(tagName, [propeties], children)` to create a virtual dom tree
var tree = el('div', {'id': 'container'}, [
    el('h1', {style: 'color: blue'}, ['simple virtal dom']),
    el('p', ['Hello, virtual-dom']),
    el('ul', [el('li')])
])

// 2. generate a real dom from virtual dom. `root` is a `div` element
var root = tree.render()

// 3. generate another different virtual dom tree
var newTree = el('div', {'id': 'container'}, [
    el('h1', {style: 'color: red'}, ['simple virtal dom']),
    el('p', ['Hello, virtual-dom']),
    el('ul', [el('li'), el('li')])
])

// 4. diff two virtual dom trees and get patches
var patches = diff(tree, newTree)

// 5. apply patches to real dom
patch(root, patches)

// now the `root` dom is updated

You can checkout the full example in example folder.

You should always provide a unique key property for each child in array(just like ReactJS's keyed children) for Virtual-DOM to reorder children instead of replacing the whole list when perform diff algorithm.

var root = el('ul', [
  el('li', {key: 'uid1'}, ['Jerry']),
  el('li', {key: 'uid2'}, ['Tomy']),
  el('li', {key: 'uid3'}, ['Lucy']),
])

var newRoot = el('ul', [
  el('li', {key: 'uid1'}, ['Jerry']),
  el('li', {key: 'uid2'}, ['Tomy']),
  el('li', {key: 'uid4'}, ['Lily']),
  el('li', {key: 'uid3'}, ['Lucy']),
])

// ensure `patches` is minimum
var patches = diff(root, newRoot)

The MIT License (MIT)

Copyright (c) 2015 Livoras

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.