Web component using slots

HTML

<script src="https://cdn.rawgit.com/webcomponents/webcomponentsjs/3b3bd26f/webcomponents-lite.js"></script>
<my-components>
    <p slot="header">
      header
    </p>
     <p slot="footer">
      footer
    </p>
</my-components>

JavaScript

/*
// src code
customElements.define('my-components', class extends HTMLElement {
  constructor() {
  	super()
    var root = this.attachShadow({mode: 'open'});
    root.innerHTML = `
      <slot name="footer"></slot>
      <slot name="header"></slot>
    `
  }
});

*/

'use strict';

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

// src code
customElements.define('my-components', function (_HTMLElement) {
  _inherits(_class, _HTMLElement);

  function _class() {
    _classCallCheck(this, _class);

    var _this = _possibleConstructorReturn(this, _HTMLElement.call(this));
    
    function connectedCallback() {
    	console.log("connected");
    }

    var root = _this.attachShadow({ mode: 'open' });
    root.innerHTML = '\n      <slot name="footer"></slot>\n      <slot name="header"></slot>\n    ';
    return _this;
  }

  return _class;
}(HTMLElement));