Complex tags, like the HTML5 date picker, are actually sophisticated HTML structures provided behind the scenes by browser vendors. The new Web Components specification enables developers to create their own hidden implementations of HTML elements.
Although this new standard isn't integrated into all browsers, the "Platform" polyfill library used by both Google's Polymer and Mozilla's Brick projects, allows the use of Web Components even where native support doesn't yet exist. Better still, both Polymer and Brick offer libraries of ready-to-use components.
Web Components in Action is a thorough introduction to the new W3C Web Components specification. It shows how to build complex web apps with Web Components and the Polymer framework using Shadow DOM, Model Driven Views, and custom elements.
Readers will learn to build tags that capture reusable parts of an application and even how to wrap and reuse a whole application.Along the way, they'll discover how using existing and custom Web Components make web applications easier to build, read, and maintain.