loadPage method

Future loadPage({ PageKeyType? nextPageKey, bool isRefresh = false, })

Implementation

Future loadPage({PageKeyType? nextPageKey, bool isRefresh = false}) async {
  if (cancelableOperation != null && !cancelableOperation!.isCompleted) {
    cancelableOperation!.cancel();
  }
  var items =
      _pagingState.maybeMap((value) => value.items, orElse: () => null);
  cancelableOperation = CancelableOperation.fromFuture(
      dataSource.loadPage(isRefresh: isRefresh, newKey: nextPageKey));
  cancelableOperation!.value.then((value) {
    int? itemCount = isRefresh
        ? [...value].length
        : items != null
            ? [...items, ...value].length
            : [...value].length;

    bool hasNextPage = dataSource.currentKey != null && !dataSource.isEndList;

    bool hasItems = itemCount > 0;

    bool isListingUnfinished = hasItems && hasNextPage;

    bool isOngoing = isListingUnfinished;

    bool isCompleted = hasItems && !hasNextPage;

    /// The current pagination status.
    PagingStatus status =
        (isOngoing) ? PagingStatus.ongoing : PagingStatus.completed;

    emit(PagingState<PageKeyType, ItemType>(
        isRefresh
            ? [...value]
            : items != null
                ? [...items, ...value]
                : [...value],
        status,
        false));
  }, onError: (e) {
    if (dataSource.currentKey == null) {
      emit(PagingState<PageKeyType, ItemType>.error(e));
    } else {
      _pagingState.maybeMap(
          (value) => emit(PagingState<PageKeyType, ItemType>(
              value.items, PagingStatus.noItemsFound, true)),
          orElse: () => null);
    }
  });
  // await dataSource.loadPage(isRefresh: isRefresh).then((value) {
  //   int? itemCount = isRefresh
  //   ? [...value].length
  //       : items != null
  //   ? [...items, ...value].length
  //       : [...value].length;
  //
  //   bool hasNextPage = dataSource.currentKey != null && !dataSource.isEndList;
  //
  //   bool hasItems = itemCount > 0;
  //
  //   bool isListingUnfinished = hasItems && hasNextPage;
  //
  //   bool isOngoing = isListingUnfinished;
  //
  //   bool isCompleted = hasItems && !hasNextPage;
  //
  //   /// The current pagination status.
  //   PagingStatus status =
  //   (isOngoing) ? PagingStatus.ongoing : PagingStatus.completed;
  //
  //   emit(PagingState<PageKeyType, ItemType>(
  //   isRefresh
  //   ? [...value]
  //       : items != null
  //   ? [...items, ...value]
  //       : [...value],
  //   status,
  //   false));
  // }, onError: (e) {
  //   if (dataSource.currentKey == null) {
  //     emit(PagingState<PageKeyType, ItemType>.error(e));
  //   } else {
  //     _pagingState.maybeMap(
  //             (value) => emit(PagingState<PageKeyType, ItemType>(
  //             value.items, PagingStatus.noItemsFound, true)),
  //         orElse: () => null);
  //   }
  // });
}