How to make a downloader that would run for some time?

[m-haisham]

Assume I have a list of items and I want to download some content to it. I have tried the following:

Below is a minimal implementation with some classes that I don't think are important missing.

class Item {
    final String name;
    final List<int>? content;
    final DownloadState downloadState;  // pending, inProgress, complete
}

final itemListController = StateNotifierProvider<ItemListController, List<Item>>(
    (ref) => [
        // Dummy data
        Item('item1', const DownloadState.pending());
        Item('item2', const DownloadState.pending());
        Item('item3', const DownloadState.pending());
        Item('item4', const DownloadState.pending());
    ];
);

final downloadController = StateNotifierProvider<DownloadController, DownloadControllerState>(
    (ref) {
        // Needs items to know which is pending
        //
        // I would like to update the list to show what is being downloaded
        // and what is pending.
        //
        // But if i update itemList it would destroy downloadController
        // as this depends on itemList
        return DownloadController(ref.watch(itemListController));
    };
);

Thanks in advance.

[rrousselGit]

You probably don't want to use watch and instead want to use listen

StateNotifierProvider<DownloadController, State>((ref) {
  final controller = DownloadController();
  ref.listen<List<Item>>(itemListController, (_, itemList) {
    // do something with itemList
  });
  return controller;
});

[m-haisham]

Thank you very much