Function scheduleDelayedPrefetching

packages/core/src/defer/triggering.ts:106–126

(
  scheduleFn: (callback: VoidFunction, injector: Injector) => VoidFunction,
)

 * @param scheduleFn A function that does the scheduling.
 */
export function scheduleDelayedPrefetching(
  scheduleFn: (callback: VoidFunction, injector: Injector) => VoidFunction,
) {
  if (typeof ngServerMode !== 'undefined' && ngServerMode) return;

  const lView = getLView();
  const injector = lView[INJECTOR];

  // Only trigger the scheduled trigger on the browser
  // since we don't want to delay the server response.
  const tNode = getCurrentTNode()!;
  const tView = lView[TVIEW];
  const tDetails = getTDeferBlockDetails(tView, tNode);

  if (tDetails.loadingState === DeferDependenciesLoadingState.NOT_STARTED) {
    const lDetails = getLDeferBlockDetails(lView, tNode);
    const prefetch = () => triggerPrefetching(tDetails, lView, tNode);
    const cleanupFn = scheduleFn(prefetch, injector);
    storeTriggerCleanupFn(TriggerType.Prefetch, lDetails, cleanupFn);
  }
}

/**
 * Schedules hydration triggering of a defer block for `on idle` and `on timer` conditions.