Function collectDomEventsInfo

packages/core/src/hydration/event_replay.ts:230–273

(
  tView: TView,
  lView: LView,
  eventTypesToReplay: {regular: Set<string>; capture: Set<string>},
)

 * LView. Maps collected events to a corresponding DOM element (an element is used as a key).
 */
export function collectDomEventsInfo(
  tView: TView,
  lView: LView,
  eventTypesToReplay: {regular: Set<string>; capture: Set<string>},
): Map<Element, string[]> {
  const domEventsInfo = new Map<Element, string[]>();
  const lCleanup = lView[CLEANUP];
  const tCleanup = tView.cleanup;
  if (!tCleanup || !lCleanup) {
    return domEventsInfo;
  }
  for (let i = 0; i < tCleanup.length; ) {
    const firstParam = tCleanup[i++];
    const secondParam = tCleanup[i++];
    if (typeof firstParam !== 'string') {
      continue;
    }
    const eventType = firstParam;
    if (!isEarlyEventType(eventType)) {
      continue;
    }
    if (isCaptureEventType(eventType)) {
      eventTypesToReplay.capture.add(eventType);
    } else {
      eventTypesToReplay.regular.add(eventType);
    }
    const listenerElement = unwrapRNode(lView[secondParam]) as any as Element;
    i++; // move the cursor to the next position (location of the listener idx)
    const useCaptureOrIndx = tCleanup[i++];
    // if useCaptureOrIndx is boolean then report it as is.
    // if useCaptureOrIndx is positive number then it in unsubscribe method
    // if useCaptureOrIndx is negative number then it is a Subscription
    const isDomEvent = typeof useCaptureOrIndx === 'boolean' || useCaptureOrIndx >= 0;
    if (!isDomEvent) {
      continue;
    }
    if (!domEventsInfo.has(listenerElement)) {
      domEventsInfo.set(listenerElement, [eventType]);
    } else {
      domEventsInfo.get(listenerElement)!.push(eventType);
    }
  }
  return domEventsInfo;
}

export function invokeRegisteredReplayListeners(
  injector: Injector,