Draft: Downloads in dart with simpler interface without Databases #793

rekire · 2023-01-15T09:46:46Z

This is my draft for a 2.0 refactoring. I would like to get some feedback.

Progress

Platform	Download	Progress	Pausing	Resuming	Cancel	Deletion	Show paused downloads
Android	☑️	☑️	☑️	☑️	☑️	☑️	☑️
iOS	☑️	☑️	☑️	☑️	☑️	☑️	☑️
Windows	☑️	☑️	☑️	☑️	☑️	☑️	☑️
MacOS	☑️	☑️	☑️	☑️	☑️	☑️	☑️

Things I want to do before merging:

Improvements

fixes Add support for macOS #391
fixes Add support for Windows #617
No database used
No init calls
Simpler interface (with legacy support as far as possible)
You can observe now the FlutterDownloader and the Downloads with the ChangeNotifier API
Windows support
MacOS support

Breaking changes

Database and therefore old progress are lost
The progress is now in permille instead of percent (which make any progress bar more smoothly)

Technical details

The Download class/interface is the front end the user should use. There are two implementations:

DartDownload is the implementation of the Download which has the ability to download files in pure dart code which is used for Desktop platforms and provides the status updates etc.
PlatformDownload is an extended Version of the DartDownload which delegates downloads to platform implementations and get notified about progress from the native world and forward those details to the Flutter world.

Usage samples

Start a download

const sampleUrl = 'https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4';
final download = await FlutterDownloader().startDownload(sampleUrl);
download.addListener(() {
  if (download.status == DownloadStatus.complete || download.status == DownloadStatus.failed) {
    print('Download ended');
  }
  print('Progress: ${download.progress / 10.0}%');
});

Pause and resume a download

final download = await FlutterDownloader().startDownload(sampleUrl);
await download.pause();
// do something like app restart
await download.resume();

Get downloads (e.g. after restart)

final downloads = await FlutterDownloader().getDownloads();

Observe all downloads at once

final downloads = await FlutterDownloader().getDownloads();
final all = DownloadGroup(downloads);
await all.pause(); // pause all downloads
await all.resume(); // resume all downloads
all.addListener(() {
  print('Downloading ${all.downloads.length} files with an overall progress of ${all.progress / 10.0}%');
});

…k manager

Apply suggestions from code review Co-authored-by: Bartek Pacia <[email protected]>

rekire · 2023-02-09T06:00:21Z

FYI: I had the last days not a lot of time, but I will continue

bartekpacia · 2023-02-09T09:46:53Z

awesome :D

lyio · 2023-02-14T15:11:47Z

I have a question about how the API/usage of the plugin will change with this PR.

In the 1.0 version, I would schedule my download and let the platform handle everything. I would get a taskId when scheduling the download so I can keep track of the downloads on my side of things.

This seems to be gone now, is that correct? I get a Download object that has the url as the only identifying information.

Also, the listener I can attach does not actually inform me about individual downloads, does it? I can only ask about all downloads and match them myself.

The progress and status APIs seem to only allow tracking of one download at a time. Is this the intended use?

rekire · 2023-02-14T19:32:14Z

@lyio, you point out something interesting which I had not yet in mind.

With the code structure I have in mind you can query all downloads, then you need to filter out the download you are interested in. Each download has as you correctly found out a progress (in permille) and a status. Changes of those value will be notified (e.g. for UI). I had in mind that you can observe in that way a single Download or the overall progress when you observe the FlutterDownloader class.

As said you would need to find the download you are interested in yourself. I will think about a simpler way to give you the progress of a single download in a simpler way. I had already in mind to provide the progress of a group of downloads. But I want to have the basics done first.

By the way I'm currently working on the migration to the JSON structure, which takes (as expected) relativ high amount of time since I need to handle it differently on multiple platforms. When this works as expected I will push an update.

lyio · 2023-02-16T07:52:20Z

@rekire in v1 the plugin returned a taskId which could be used to properly identify the download. Could this be added again in v2? Otherwise you could only identify the download by its url, which seems a bit odd.

bartekpacia · 2023-02-16T11:22:54Z

I agree that each task having a unique ID of some sorts is a nice feature.

rekire · 2023-02-22T06:30:46Z

To be honest I see nothing useful in a random identifier... What about the hash of the url? I'm using it as id internal

781flyingdutchman · 2023-02-24T06:01:05Z

@rekire I've made quite a bit of progress on the background_downloader package that we have discussed before, and in issue #823 I am suggesting we could consider that package as a candidate for V2.0 of flutter_downloader. I know you're working on this too, so just wanted to let you know that I have no horse in this race, as they say! If you all would rather go further down this path, I am totally fine with that. I just wanted to offer an alternative that is already fully functional.

rekire · 2023-02-26T15:37:03Z

@bartekpacia what does the CI try to say me with the broken test? Out of my view the file which breaks the test does not exist.

rekire · 2023-03-03T20:19:04Z

@781flyingdutchman I just looked into your repo again, you made huge improvements since the last time I checked it. To take your metaphor of the horse race you would be ahead. I see that you added in the mean time also uploads and progress for groups of downloads.

The only thing I still don't really like is that you have negative progress values for some error cases. I'm currently fighting with that resuming downloads on mobile after app restarts, but what is actually working on other platforms right now. I count pausing and resuming as important, what is your timeline for your 5.0 and will this really be a breaking change what the major version change implies? In this small detail I'm might be a bit ahead.

Just general speaking you should just close bugs when they are done that was confusing me a bit while checking your progress.

Anyway great work and I'm not really sure what is better now, your or my approach

bartekpacia · 2023-03-03T21:29:17Z

what does the CI try to say me with the broken test? Out of my view the file which breaks the test does not exist.

It's a false positive. One of the analyzer rules ('implicit-casts) became removed. The solution is to remove flutter beta from the CI.

rekire · 2023-03-04T10:30:50Z

I have now the basic functionally done. I have just a bug on iOS that the current progress (just the progressbar) cannot be recovered after an app restart, but the download will continue on all Platforms with JSON files.

rekire · 2023-03-04T22:14:38Z

@bartekpacia I'm now happy with the current status could you review my changes now?

I would like to split out the open points into separate PRs:

Following redirects in dart (deduplicate code)
Reading the filename from response headers in dart (deduplicate code)
Code sample how to handle notifications with permission management
Use the scoped storage API on Android to provide the downloads

What is still open:

Move the finished downloads somewhere and expose the path to the client
Extend documentation, but I'm not really sure what is currently missing
Resolve the merge conflicts

Do you see something else missing? Might be even considering to use the work of 781flyingdutchman it's up to you

781flyingdutchman · 2023-03-05T06:52:36Z

HI @rekire and @bartekpacia apologies I didn't see your message, but I did just publish V5 which supports pause/resume. It passes all my tests, and I'm curious to see how it behaves in the wild!

bartekpacia

Thank you for your work. I left some comments.

bartekpacia · 2023-03-12T13:09:01Z

android/build.gradle

@@ -1,8 +1,8 @@
-group 'vn.hunghd.flutterdownloader'
+group 'com.github.fluttercommunity.flutterdownloader'


Let's use double quotes for all strings. It'll be easier to convert to Gradle Kotlin DSL in the future.

bartekpacia · 2023-03-12T13:14:08Z

lib/src/flutter_downloader.dart

+part 'legacy_api.dart';
+
+/// The target where the download should be visible for the user.
+enum DownloadTarget {


It'd be great if you added what methods can be used to access files under each of these paths.

For example, explain that path_provider.getDownloadsDirectory() can be used to access the file if its download target is downloadsFolder.

bartekpacia · 2023-03-12T13:15:20Z

lib/src/flutter_downloader.dart

+part 'legacy_api.dart';
+
+/// The target where the download should be visible for the user.
+enum DownloadTarget {


Can the user specify an arbitrary path where they want to save the file?

bartekpacia · 2023-03-12T13:15:41Z

lib/src/flutter_downloader.dart

+  @override
+  DownloadStatus get status => throw UnimplementedError();
+
+  // TODO check if that is required in the future


bartekpacia · 2023-03-12T13:16:44Z

lib/src/flutter_downloader.dart

+    final files = await baseDir.list().toList();
+    final downloads = <Download>[];
+    for (final file in files) {
+      //print('checking File: ${file.path}');


Let's make FlutterDownloader accept an optional function argument called logger. By default it's null, but the user can pass whatever they want to get logs from the internals of FlutterDownloader.

bartekpacia · 2023-03-12T13:18:11Z

lib/src/legacy_api.dart

+  }
+
+  /// Left for compatibility returns false.
+  @Deprecated('There is no replacement')


That's a pity. How hard would it be to provide a replacement?

bartekpacia · 2023-03-12T13:19:05Z

lib/src/platform_download.dart

+
+/// A platform specific [Download] which invokes the method channel and make the
+/// download native if the platform has this requirement.
+class PlatformDownload extends DesktopPlatformDownload {


I can use PlatformDownload on mobile, yet it inherits from DesktopPlatformDownload? Seems a bit wrong to me.

bartekpacia · 2023-03-12T13:19:50Z

lib/src/platform_download.dart

+  static Future<PlatformDownload> fromDirectory(
+    String baseDir,
+    String id,
+  ) async =>


Let's use the block body.

I use arrow body only when the whole function fits into a single line, otherwise it looks ugly, imho.

bartekpacia · 2023-03-12T13:21:18Z

test/example_test.dart

+}
+
+/// Run a test in a temp directory, which will be deleted after the execution.
+dynamic Function() isolated(Future<dynamic> Function(Directory testDir) body) {


You might want to use package:file for this - it abstracts the concrete file system and provides a useful MemoryFileSystem for use in testing.

bartekpacia · 2023-03-12T16:10:10Z

@rekire Please rebase with master to fix CI being red.

rekire · 2023-05-04T20:00:08Z

Just a quick update from me. I'm observing now for month the progress of the background_downloader of @781flyingdutchman and he is doing a great job out of my view. I have simply not the time to apply the changes as quickly. Therefore I would suggest to check if both packages could be merged to get a bigger audience.

bartekpacia · 2023-05-10T21:18:46Z

Thank you for your work @rekire. I agree with the comment above.

background_downloader does look nice. However, I'd like it to:

be in flutter community, to ensure it doesn't become abandoned
have good documentation (can be done easily with docs.page), like e.g. melos or patrol have.

I didn't use it personally though, and honestly, I think I'll try to write the code myself. I'm realizing that 90% of Flutter plugins are of very low quality, become abandoned easily, and in the long run bring more harm than good.

I tried my best to improve this plugin but failed. Sorry about this.

rekire and others added 23 commits September 11, 2022 22:12

Add basic Android 13 support

17ef212

Convert classes to kotlin

d0b332c

Add missing imports and fix some null value issues

503a104

Rename variable

914cacd

Native download basement

da64872

Reformat generation of metadata

dcacc92

Fix test on Windows

3d8aa48

Add way to isolate tests

27ebe3b

Playing with platform interface

e5c6781

Migrate to simplified API

673a16a

Migrate sample app to new api

1f3fcb3

Extend download class to keep track of progress

8a30069

Deprecate legacy api and add a migration path

642c454

Sync UI with ValueNotifier

1e2e82d

Track download progress

1dd5ff2

Fix memory leak and download progress

39d2262

Add code to resume downloads

0d976a0

Make pause and resuming working

e236787

Rename files

2ef9e50

Add abstraction layer to support platform specific overrides

ce3ef3a

Sync Dart with Android code

1c29f12

Make the download working without status updates on Android using wor…

8bb4da7

…k manager

Add progress updates from Android

b561b92

rekire mentioned this pull request Jan 15, 2023

Quick review #713

Closed

rekire added 6 commits January 15, 2023 12:20

Random changes after running app in emulator

ef8195b

Hello objective C: Avoid crashes

634c317

Update iOS meta data

cab5a4a

Add swift support and delete legacy code

e8a53b7

Add Linux sample app

5cb7f98

Add MacOS sample app

3adbe75

rekire and others added 4 commits January 30, 2023 09:39

Update documentation

ab42221

Apply suggestions from code review Co-authored-by: Bartek Pacia <[email protected]>

Extend documentation and some refactoring

ac02b88

Simplify code

a2ec20f

Yet another simplifying pass with migration to the JSON format

8759a6a

rekire added 2 commits February 26, 2023 08:22

Class renamings and migration to json config

1abf64c

Deduplicate code for metadata and make state recovering working again

7be20ac

Partially safe progress on iOS

ba9b83b

Resume downloads on Android

b9eeb20

Add support for observing and controlling groups of downloads

fa53de2

bartekpacia reviewed Mar 12, 2023

View reviewed changes

bartekpacia mentioned this pull request Mar 12, 2023

Clean up API #283

Closed

2 tasks

rekire closed this May 4, 2023

bartekpacia mentioned this pull request May 10, 2023

This package has no maintainer #854

Closed

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Draft: Downloads in dart with simpler interface without Databases #793

Draft: Downloads in dart with simpler interface without Databases #793

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		@@ -1,8 +1,8 @@
		group 'vn.hunghd.flutterdownloader'
		group 'com.github.fluttercommunity.flutterdownloader'

Draft: Downloads in dart with simpler interface without Databases #793

Draft: Downloads in dart with simpler interface without Databases #793

Conversation

rekire commented Jan 15, 2023 • edited Loading

Progress

Improvements

Breaking changes

Technical details

Usage samples

Start a download

Pause and resume a download

Get downloads (e.g. after restart)

Observe all downloads at once

rekire commented Feb 9, 2023

bartekpacia commented Feb 9, 2023

lyio commented Feb 14, 2023

rekire commented Feb 14, 2023 • edited Loading

lyio commented Feb 16, 2023

bartekpacia commented Feb 16, 2023

rekire commented Feb 22, 2023

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rekire commented Feb 26, 2023

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