Actions after download is completed

[HSCT]

Where do i process the downloaded file after download action is completed? For examples, if I download a .zip file, I'd want to write a function to extract the file right away. Where can I put the extract function? I tried to put function extract() in _bindBackgroundIsolate() and it worked, but only when I'm at the widget that contains _bindBackgroundIsolate(). If I'm at another widget, function extract() doesn't run at all

Edit: to be exact, i put function extract() inside port.listen to get the complete event. But as far as I know, port is define as a ReceivePort, and it is not a broadcast stream, so calling port.listen from another widget will not work

[781flyingdutchman]

If you need to process download events elsewhere (i.e. outside of the _port.listen method) then you can send the update via a normal flutter stream to anywhere you want, ad that can also be a broadcast stream. For example:

IsolateNameServer.registerPortWithName(
        _port.sendPort, 'downloader_send_port');
    _port.listen((dynamic data) {
      /// process incoming data by passing it to the callbacks
      String taskId = data[0];
      DownloadTaskStatus status = data[1];
      if (finalStates.contains(status)) {
        // we have reached an end point
        if (_numberOfRunningTasks != null) _numberOfRunningTasks--;
        _numberCompleted++;
        // determine the appropriate callback
        if (status == DownloadTaskStatus.complete) {
          _updateStream.add(DownloadUpdate(taskId, DownloadState.downloaded));
          return;
        }
        if (status == DownloadTaskStatus.failed) {
          _updateStream
              .add(DownloadUpdate(taskId, DownloadState.downloadError));
          return;
        }
        if (status == DownloadTaskStatus.canceled) {
          _updateStream.add(DownloadUpdate(taskId, DownloadState.canceled));
          return;
        }
      }
    });

[abdullah432]

@HSCT Do you got it?

[bartekpacia]

This is a more complex use case.

I've successfully implemented it in my app. Here's a very rough description of what I do:

1. I listen for download task updates using ReceivePort.listen((data) => callback)
2. When a callback is called, then I call FlutterDownloader.loadTasks()
3. I loop over tasks and when a task is successful, I take the path to the downloaded file and extract the zip archive.

I think that the example app should demonstrate it. I'll try to work on it during the holidays. Meanwhile, contributions are welcome :)