Html Import

What is it ?

Include an HTML element inside another one

How ?

• CORS
• Load once
• Don't block page parsing

Get the content

HTML and CSS are just loaded but not included (available) We retrieve the content using the import property

And for Javascript ...

• Run in the page context
• Can access to its DOM ...
• ... and the one from the page

Events

Load and Error Event

Support

Shadow Dom

Old !!!!

Browsers already use it

What is it ?

It's all about Encapsulation

What does this mean

• Isolated container
• New kind of node
• shadow root
• shadow host

With Javascript

• createShadowRoot
• element.shadowRoot

Normal button!
Hello, world!

Shadow DOM versus Light DOM

            
Hello

        

• visible sub-tree (childNodes, children, innerHTML ...)
• internal node
• composed DOM: what the browser see and render

Insertions points

• Define render area in the shadow dom
• No logical link

Template

What is it ?

Reusable DOM template

Not in the document

No side effect

• DOM not rendered
• Script not parsed
• Image not loaded

Usage

Exemple

Support

Custom element

What is it ?

• Define new HTML element
• Extend existing elements

How ?

• registerElement
• a name (with a -)
• a prototype (HTMLElement by default)

Extend existing elements

Lifecycle

Declaration vs register

• Seen as unresolved

• pseudo-selector :unresolved

            
registerRegister
            
        

Callback

• createdCallback
• attachedCallback
• detachedCallback
• attributeChangedCallback

            
var myElemtProto = Object.create(HTMLElement.prototype);

myElemtProto.createdCallback = function() {};

var myElemt = document.registerElement('my-element', myElemtProto);
            
        

Add content

innerHTML

            
myEltProto.createdCallback = function() {
this.innerHTML = "un peu de contenu!";
};
            
        

shadowDom

            
myEltProto.createdCallback = function() {
var shadow = this.createShadowRoot();
shadow.innerHTML = "un peu de contenu!";
};
            
        

Template

            


myEltProto.createdCallback = function() {
var t = document.querySelector('#sdtemplate');
var clone = document.importNode(t.content, true);
this.createShadowRoot().appendChild(clone);
};
            
        

Add code

The prototype

myEltProto.myFctn=function(){...}
Object.defineProperty(myEltProto, "bar", {value: 5});

        

Support

And so what ?

Real good specification

Can be used alone

But a weak support

So what can we do ?

POLYMER

• polyfills (platform.js)
• components (core-elements, paper-elements)
• sugaring (polymer.js)

X-TAG

• Web Components Polyfills (custom element et HTMLImports)
• X-Tag Custom Elements
• X-Tag Core Library

BOSONIC

• polyfills (platform.js)
• components