Function injectAsync

packages/core/src/di/inject_async.ts:58–85

(
  loader: () => Promise<InjectAsyncLoaderResult<T>>,
  options?: InjectAsyncOptions,
)

  options?: InjectAsyncOptions,
): () => Promise<T>;
export function injectAsync<T>(
  loader: () => Promise<InjectAsyncLoaderResult<T>>,
  options?: InjectAsyncOptions,
): () => Promise<T> {
  if (ngDevMode) {
    assertInInjectionContext(injectAsync);
  }

  const injector = inject(Injector);

  let loadedPromise: Promise<InjectAsyncLoaderResult<T>> | null = null;
  const load = () => {
    if (!loadedPromise) {
      loadedPromise = loader();
    }
    return loadedPromise;
  };

  if (options?.prefetch) {
    options
      .prefetch()
      .then(() => load())
      .catch(() => {});
  }

  // We can't use `inject` later on because of the async nature of the loader
  return () => load().then((loadedToken) => injector.get(maybeUnwrapDefaultExport(loadedToken))!);
}

/**
 * Interface for `options` argument used within `injectAsync` call.