- A first webcomponent (et2-button)

- Some mixin logic, not used but available

api/js/etemplate/et2_core_inheritance.ts

@@ -16,6 +16,69 @@ import {egw} from "../jsapi/egw_global";
 import {et2_checkType, et2_no_init, et2_validateAttrib} from "./et2_core_common";
 import {et2_implements_registry} from "./et2_core_interfaces";
 
+// Needed for mixin
+export function mix (superclass)
+{
+	return new MixinBuilder(superclass);
+}
+export class MixinBuilder {
+	constructor(superclass) {
+		this.superclass = superclass;
+	}
+
+	with(...mixins) {
+		return mixins.reduce(this.applyMixins, this.superclass);
+	}
+	applyMixins(derivedConstructor: any, baseConstructor: any) {
+		Object.getOwnPropertyNames(baseConstructor.prototype)
+			.forEach(name => {
+				Object.defineProperty(derivedConstructor.prototype,
+					name,
+					Object.
+					getOwnPropertyDescriptor(
+						baseConstructor.prototype,
+						name
+					)
+				);
+			});
+	}
+	 copyProperties(target, source) {
+		for (let key of Reflect.ownKeys(source)) {
+			if (key !== "constructor" && key !== "prototype" && key !== "name") {
+				let desc = Object.getOwnPropertyDescriptor(source, key);
+				Object.defineProperty(target, key, desc);
+			}
+		}
+	}
+}
+
+// This one from Typescript docs
+export function applyMixins(derivedCtor: any, constructors: any[]) {
+  constructors.forEach((baseCtor) => {
+    Object.getOwnPropertyNames(baseCtor.prototype).forEach((name) => {
+      Object.defineProperty(
+        derivedCtor.prototype,
+        name,
+        Object.getOwnPropertyDescriptor(baseCtor.prototype, name) ||
+          Object.create(null)
+      );
+    });
+  });
+}
+
+/*
+Experiments in using mixins to combine et2_widget & LitElement
+Note that this "works", in that it mixes the code properly.
+It does not work in that the resulting class does not work with et2's inheritance & class checking stuff
+
+// This one to make TypeScript happy?
+interface et2_textbox extends et2_textbox, LitElement {}
+// This one to make the inheritance magic happen
+applyMixins(et2_textbox, [et2_textbox,LitElement]);
+// Make it a real WebComponent
+customElements.define("et2-textbox",et2_textbox);
+
+ */
 export class ClassWithInterfaces
 {
 	/**