Function createOverlayRef

src/cdk/overlay/overlay.ts:52–116

(injector: Injector, config?: OverlayConfig)

 * @returns Reference to the created overlay.
 */
export function createOverlayRef(injector: Injector, config?: OverlayConfig): OverlayRef {
  // This is done in the overlay container as well, but we have it here
  // since it's common to mock out the overlay container in tests.
  injector.get(_CdkPrivateStyleLoader).load(_CdkOverlayStyleLoader);

  const overlayContainer = injector.get(OverlayContainer);
  const doc = injector.get(DOCUMENT);
  const idGenerator = injector.get(_IdGenerator);
  const appRef = injector.get(ApplicationRef);
  const directionality = injector.get(Directionality);
  const renderer =
    injector.get(Renderer2, null, {optional: true}) ||
    injector.get(RendererFactory2).createRenderer(null, null);

  const overlayConfig = new OverlayConfig(config);
  const defaultUsePopover =
    injector.get(OVERLAY_DEFAULT_CONFIG, null, {optional: true})?.usePopover ?? true;

  overlayConfig.direction = overlayConfig.direction || directionality.value;

  if (!('showPopover' in doc.body)) {
    overlayConfig.usePopover = false;
  } else {
    overlayConfig.usePopover = config?.usePopover ?? defaultUsePopover;
  }

  const pane = doc.createElement('div');
  const host = doc.createElement('div');
  pane.id = idGenerator.getId('cdk-overlay-');
  pane.classList.add('cdk-overlay-pane');
  host.appendChild(pane);

  if (overlayConfig.usePopover) {
    host.setAttribute('popover', 'manual');
    host.classList.add('cdk-overlay-popover');
  }

  const customInsertionPoint = overlayConfig.usePopover
    ? overlayConfig.positionStrategy?.getPopoverInsertionPoint?.()
    : null;

  if (isElement(customInsertionPoint)) {
    customInsertionPoint.after(host);
  } else if (customInsertionPoint?.type === 'parent') {
    customInsertionPoint.element.appendChild(host);
  } else {
    overlayContainer.getContainerElement().appendChild(host);
  }

  return new OverlayRef(
    new DomPortalOutlet(pane, appRef, injector),
    host,
    pane,
    overlayConfig,
    injector.get(NgZone),
    injector.get(OverlayKeyboardDispatcher),
    doc,
    injector.get(Location),