ionic-framework/packages/angular/src/util/util.ts

export function hydrateElement(element: any) {
  return element.componentOnReady();
}

export function getElement(elementName: string) {
  return document.querySelector(elementName);
}

export function ensureElementInBody(elementName: string) {
  let element = getElement(elementName);
  if (!element) {
    element = document.createElement(elementName);
    document.body.appendChild(element);
  }
  return element;
}

export function removeAllNodeChildren(element: HTMLElement) {
  while (element.firstChild) {
    element.removeChild(element.firstChild);
  }
}

export function isString(something: any) {
  return typeof something === 'string' ? true : false;
}

export function ensureExternalRounterController(): Promise<HTMLIonExternalRouterControllerElement> {
  const element = document.querySelector('ion-external-router-controller');
  if (element) {
    return (element as any).componentOnReady();
  }
  const toCreate = document.createElement('ion-external-router-controller');
  document.body.appendChild(toCreate);
  return (toCreate as any).componentOnReady();
}