Function dispatchEvent

code/composition/public/app.js:6059–6083

(topLevelType, nativeEvent)

}

function dispatchEvent(topLevelType, nativeEvent) {
  if (!_enabled) {
    return;
  }

  var nativeEventTarget = getEventTarget(nativeEvent);
  var targetInst = getClosestInstanceFromNode(nativeEventTarget);
  if (targetInst !== null && typeof targetInst.tag === 'number' && !isFiberMounted(targetInst)) {
    // If we get an event (ex: img onload) before committing that
    // component's mount, ignore it for now (that is, treat it as if it was an
    // event on a non-React tree). We might also consider queueing events and
    // dispatching them after the mount.
    targetInst = null;
  }

  var bookKeeping = getTopLevelCallbackBookKeeping(topLevelType, nativeEvent, targetInst);

  try {
    // Event queue being processed in the same cycle allows
    // `preventDefault`.
    batchedUpdates(handleTopLevel, bookKeeping);
  } finally {
    releaseTopLevelCallbackBookKeeping(bookKeeping);
  }
}

var ReactDOMEventListener = Object.freeze({
	get _enabled () { return _enabled; },