added base element

app/elements/_base.ts

@@ -0,0 +1,18 @@
+export class BaseElement extends HTMLElement {
+    private _hasConnectedCallback: boolean = false;
+    connectedCallback() {
+
+        if (!this._hasConnectedCallback) {
+            this.onInit();
+        }
+        else {
+            this.onUpdate();
+        }
+
+        this._hasConnectedCallback = true;
+
+    }
+
+    onInit() { }
+    onUpdate() { }
+}

app/elements/app-root/app-root.less

@@ -0,0 +1,5 @@
+app-root {
+    width: 100%;
+    height: 100%;
+    display: block;
+}

app/elements/app-root/app-root.ts

@@ -0,0 +1,12 @@
+import { BaseElement } from "../_base";
+import './app-root.less';
+
+export class AppRoot extends BaseElement {
+    onInit(): void {
+        console.log("APP ROOT INIT");
+    }
+
+    onUpdate(): void {
+        console.log("APP ROOT UPDATE");
+    }
+}