dees-domtools/ts/domtools.classes.elementinstrumenter.ts

import * as plugins from './domtools.plugins';
import { LitElement } from 'lit-element';

export class ElementInstrumenter {
  connectedElements = new plugins.lik.ObjectMap<LitElement>();

  public instrumentElement(elementArg: LitElement) {
    const addToConnectedElementsFunc = (eventArg: CustomEvent) => {
      this.connectedElements.add(elementArg);
    };
    const removeFromConnectedElementsFunc = eventArg => {
      this.connectedElements.remove(elementArg);
      elementArg.removeEventListener('domtools-connected', addToConnectedElementsFunc);
      elementArg.removeEventListener('domtools-disconnected', removeFromConnectedElementsFunc);
    };
    elementArg.addEventListener('domtools-connected', addToConnectedElementsFunc);
    elementArg.addEventListener('domtools-disconnected', removeFromConnectedElementsFunc);

    if (elementArg.parentElement) {
      this.connectedElements.add(elementArg); 
    }
  }

  public async forEachelement(eachFuncArg: (elementArg: LitElement) => Promise<void>) {
    for (const elementArg of this.connectedElements.getArray()) {
      await eachFuncArg(elementArg);
    }
  }
}