background_downloader 6.2.1 background_downloader: ^6.2.1 copied to clipboard
A multi-platform background file downloader and uploader. Define the task, enqueue and monitor progress
6.2.1 #
Bug fix for type cast errors and for thread safety on iOS for notifications
6.2.0 #
Added tasksFinished
method that returns true
if all tasks in the group have finished
Fixed bug related to allTasks
method
6.1.4 #
Fixed permission bug on Android 10
6.1.3 #
Added namespace
to Android build.gradle and removed irrelevant log messages
6.1.2 #
Migrating the persistent data from the documents directory to the support directory, so it is no longer visible in - for example - the iOS Files app, or the Linux home directory.
6.1.1 #
Bug fix for request
method where the httpRequestMethod
override was not taken into account properly.
6.1.0 #
Added unregisterCallBacks
to remove callbacks if you no longer want updates, and resetUpdates
to reset the updates
stream so it can be listened to again.
Bug fix for DownloadTask.withSuggestedFilename
for servers that do not follow case convention for the Content-Disposition header.
6.0.0 #
Breaking changes:
- The
TaskStatusCallback
andTaskProgressCallback
now take a single argument (TaskStatusUpdate
andTaskProgressUpdate
respectively) instead of multiple arguments. This aligns the callback API with theupdates
listener API, and makes it easier to add data to an update in the future. For example, in this version we add anexception
property to programmatically handle exceptions - Similarly, the
download
andupload
methods now return aTaskStatusUpdate
instead of aTaskStatus
- For consistency, the
taskStatus
property of theTaskRecord
(used to store task information in a persistent database) is renamed tostatus
- The
trackTasks
method no longer takes agroup
argument, and starts tracking for all tasks, regardless of group. If you need tracking only for a specific group, call the newtrackTasksInGroup
method
Other changes (non-breaking):
- You can override the
httpRequestMethod
used for requests by setting it in theRequest
,DownloadTask
orUploadTask
. By default, requests and downloads use GET (unlesspost
is set) and uploads use PUT - The
download
,upload
,downloadBatch
anduploadBatch
methods now take an optionalonElapsedTime
callback that is called at regular intervals (defined by the optionalelapsedTimeInterval
which defaults to 5 seconds) with the time elapsed since the call was made. This can be used to trigger UI warnings (e.g. 'this is taking rather long') or to cancel the task if it does not complete within a desired time. For performance reasons theelapsedTimeInterval
should not be set to a value less than one second, and this mechanism should not be used to indicate progress. - If a task fails, the
TaskStatusUpdate
will contain aTaskException
that provides information about the type of exception (e.g. aTaskFileSystemException
indicates an issue with storing or retrieving the file) and contains adescription
and (forTaskHttpException
only) thehttpResponseCode
. If tasks are tracked, the The followingTaskException
subtypes may occur:TaskException
(general exception)TaskFileSystemException
(issue retrieving or storing the file)TaskUrlException
(issue with the url)TaskConnectionException
(issue with the connection to the server)TaskResumeException
(issue with pausing or resuming a task)TaskHttpException
(issue with the HTTP connection, e.g. we received an error response from the server, captured inhttpResponseCode
)
Fixed a few bugs.
5.6.0 #
Adds handler for when the user taps a notification, and an openFile
method to open a file using the platform-specific convention.
To handle notification taps, register a callback that takes Task
and NotificationType
as parameters:
FileDownloader().registerCallbacks(
taskNotificationTapCallback: myNotificationTapCallback);
void myNotificationTapCallback(Task task, NotificationType notificationType) {
print('Tapped notification $notificationType for taskId ${task.taskId}');
}
To open a file, call FileDownloader().openFile
and supply either a Task
or a full filePath
(but not both) and optionally a mimeType
to assist the Platform in choosing the right application to use to open the file.
The file opening behavior is platform dependent, and while you should check the return value of the call to openFile
, error checking is not fully consistent.
Note that on Android, files stored in the BaseDirectory.applicationDocuments
cannot be opened. You need to download to a different base directory (e.g. .applicationSupport
) or move the file to shared storage before attempting to open it.
If all you want to do on notification tap is to open the file, you can simplify the process by
adding tapOpensFile: true
to your call to configureNotifications
, and you don't need to
register a taskNotificationTapCallback
.
5.5.0 #
Adds withSuggestedFilename
for DownloadTask
. Use:
final task = await DownloadTask(url: 'https://google.com')
.withSuggestedFilename(unique: true);
The method withSuggestedFilename
returns a copy of the task it is called on, with the filename
field modified based on the filename suggested by the server, or the last path segment of the URL, or unchanged if neither is feasible. If unique
is true, the filename will be modified such that it does not conflict with an existing filename by adding a sequence. For example "file.txt" would become "file (1).txt".
Bug fixes:
- Fix for issue #35 for pausing convenience download and a specific issue with nginx related to pause/resume
- Fix for issue #38 related to notification permissions on iOS
5.4.6 #
Fix issue #34 with moveToSharedStorage
on iOS
5.4.5 #
An invalid url in the Task
now results in false
being returned from the enqueue
call on
all platforms. Previously, the behavior was inconsistent.
5.4.4 #
Added optional properties to UploadTask
related to multi-part uploads:
fileField
is the field name used to indicate the file (default to "file")mimeType
overrides the mimeType derived from the filename extensionfields
is aMap<String, String>
containing form field name/value pairs that will be uploaded along with the file in a multi-part upload
5.4.3 #
Added optional mimeType
parameter for calls to moveToSharedStorage
and
moveFileToSharedStorage
. This sets the mimeType
directly, instead of relying on the system to determine the mime type based on the file extension.
Note that this may change the filename - for example, when moving the test file google.html
to
SharedStorage.images
while setting mimeType
to 'images/jpeg', the path to the file in shared
storage becomes /storage/emulated/0/Pictures/google.html.jpg
(note the added .jpg).
5.4.2 #
Better permissions management, implementation of moveToSharedStorage for Android versions below Q
5.4.1 #
Minor fixes
5.4.0 #
Shared and scoped storage #
The download directories specified in the BaseDirectory
enum are all local to the app. To make downloaded files available to the user outside of the app, or to other apps, they need to be moved to shared or scoped storage, and this is platform dependent behavior. For example, to move the downloaded file associated with a DownloadTask
to a shared 'Downloads' storage destination, execute the following after the download has completed:
final newFilepath = await FileDownloader().moveToSharedStorage(task, SharedStorage.downloads);
if (newFilePath == null) {
... // handle error
} else {
... // do something with the newFilePath
}
Because the behavior is very platform-specific, not all SharedStorage
destinations have the same result. The options are:
.downloads
- implemented on all platforms, but on iOS files in this directory are not accessible to other users.images
- implemented on Android and iOS only. On iOS files in this directory are not accessible to other users.video
- implemented on Android and iOS only. On iOS files in this directory are not accessible to other users.audio
- implemented on Android and iOS only. On iOS files in this directory are not accessible to other users.files
- implemented on Android only.external
- implemented on Android only
On MacOS, for the .downloads
to work you need to enable App Sandbox entitlements and set the key com.apple.security.files.downloads.read-write
to true.
On Android, depending on what SharedStorage
destination you move a file to, and depending on the OS version your app runs on, you may require extra permissions WRITE_EXTERNAL_STORAGE
and/or READ_EXTERNAL_STORAGE
. See here for details on the new scoped storage rules starting with Android API version 30, which is what the plugin is using.
Methods moveToSharedStorage
and the similar moveFileToSharedStorage
also take an optional directory
argument for a subdirectory in the SharedStorage
destination.
Thanks to @rebaz94 for implementing scoped storage on Android.
Library base directory #
The BaseDirectory
enum now also supports .applicationLibrary
. On iOS and MacOS this is the directory provided by the path_provider
package's getLibraryDirectory()
call. On Other platforms, for consistency, this is the subdirectory 'Library' of the directory returned byn the getApplicationSupportDirectory()
call.
Bug fix #
Fixed a bug with iOS cancellation in non-US locales.
5.3.0 #
Notifications #
On iOS and Android, for downloads only, the downloader can generate notifications to keep the user informed of progress also when the app is in the background, and allow pause/resume and cancellation of an ongoing download from those notifications.
Configure notifications by calling FileDownloader().configureNotification
and supply a TaskNotification
object for different states. For example, the following configures notifications to show only when actively running (i.e. download in progress), disappearing when the download completes or ends with an error. It will also show a progress bar and a 'cancel' button, and will substitute {filename} with the actual filename of the file being downloaded.
FileDownloader().configureNotification(
running: TaskNotification('Downloading', 'file: {filename}'),
progressBar: true)
To also show a notifications for other states, add a TaskNotification
for complete
, error
and/or paused
. If paused
is configured and the task can be paused, a 'Pause' button will show for the running
notification, next to the 'Cancel' button.
There are three possible substitutions of the text in the title
or body
of a TaskNotification
:
- {filename} is replaced with the filename as defined in the
Task
- {progress} is substituted by a progress percentage, or '--%' if progress is unknown
- {metadata} is substituted by the
Task.metaData
field
Notifications on iOS follow Apple's guidelines, notably:
- No progress bar is shown, and the {progress} substitution always substitutes to an empty string. In other words: only a single
running
notification is shown and it is not updated until the download state changes - When the app is in the foreground, on iOS 14 and above the notification will not be shown but will appear in the NotificationCenter. On older iOS versions the notification will be shown also in the foreground. Apple suggests showing progress and download controls within the app when it is in the foreground
While notifications are possible on desktop platforms, there is no true background mode, and progress updates and indicators can be shown within the app. Notifications are therefore ignored on desktop platforms.
The configureNotification
call configures notification behavior for all download tasks. You can specify a separate configuration for a group
of tasks by calling configureNotificationForGroup
and for a single task by calling configureNotificationForTask
. A Task
configuration overrides a group
configuration, which overrides the default configuration.
When attempting to show its first notification, the downloader will ask the user for permission to show notifications (platform version dependent) and abide by the user choice. For Android, starting with API 33, you need to add <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
to your app's AndroidManifest.xml
. Also on Android you can localize the button text by overriding string resources bg_downloader_cancel
, bg_downloader_pause
, bg_downloader_resume
and descriptions bg_downloader_notification_channel_name
, bg_downloader_notification_channel_description
. Localization on iOS is not currently supported.
5.2.0 #
Better persistence for tasks that execute while the app is suspended by the operating system.
To ensure your callbacks or listener capture events that may have happened when your app was
suspended in the background, call FileDownloader().resumeFromBackground()
right after registering
your callbacks or listener.
5.1.0 #
Previously, Android file downloads were limited to 8 minutes. Now, long downloads are possible provided the DownloadTask.allowPause
field is set to true. Just before the download times out, the downloader will pause and then resume the task in a new worker, effectively resetting the 9 minute clock. As a result, the download will eventually complete
5.0.0 #
Pause and resume #
To pause or resume a task, call:
pause
to attempt to pause a task. Whether a task can be canceled or not depends primarily on the server. Soon after the task is running (TaskStatus.running
) you can calltaskCanResume
which will return a Future that resolves totrue
if the server appears capable of pause & resume. If that returnsfalse
, then callingpause
will returnfalse
as well, and the call is ignoredresume
to resume a previously paused task, which returns true if resume appears feasible. The taskStatus will follow the same sequence as a newly enqueued task. If resuming turns out to be not feasible (e.g. the operating system deleted the temp file with the partial download) then the task will either restart as a normal download, or fail.
This adds TaskStatus.paused
which may require updating switch
statements to remain exhaustive, though this status will never appear unless you use pause.
Individual status and progress callbacks for batch upload and download #
Adds status and progress callbacks for individual files in a batch. This is breaking if you used a batch progress callback earlier, as that is now a named parameter. Change:
final result = await FileDownloader().downloadBatch(tasks, (succeeded, failed) {
print('$succeeded files succeeded, $failed have failed');
print('Progress is ${(succeeded + failed) / tasks.length} %');
});
to
final result = await FileDownloader().downloadBatch(tasks, batchProgressCallback: (succeeded, failed) {
...
});
To also monitor status and progress for each file in the batch, add a taskStatusCallback
(taking Task
and TaskStatus
as arguments) and/or a taskProgressCallback (taking
Task` and a double as arguments).
iOS minimum version from 11.0 to 13.0 #
To improve Swift code readability and maintenance, the minimum iOS version has moved from 11.0 to 13.0
4.2.3 #
Fixed another bug with database.allRecords
if taskId contains illegal filename characters (like '/'). For
tracking record id purposes those are now replaced with '_'
4.2.2 #
Fixed bug with database.allRecords
if taskId contains illegal filename characters (like '/'). For
tracking record id purposes those are now replaced with '_'
4.2.1 #
Upgraded dependency to address issue with Windows platform database performance
4.2.0 #
Added creationTime
field to Request
and Task
.
Added allRecordsOlderThan(Duration age, {String? group})
to database
, making it easy to extract
the TaskRecord
entries that are stale.
4.1.0 #
Adds optional tracking of task status and progress in a persistent database.
To keep track of the status and progress of all tasks, even after they have completed, activate tracking by calling trackTasks()
and use the database
field to query. For example:
// at app startup, start tracking
await FileDownloader().trackTasks();
// somewhere else: enqueue a download
final task = DownloadTask(
url: 'https://google.com',
filename: 'testfile.txt');
final successfullyEnqueued = await FileDownloader().enqueue(task);
// somewhere else: query the task status by getting a `TaskRecord`
// from the database
final record = await FileDownloader().database.recordForId(task.taskId);
print('Taskid ${record.taskId} with task ${record.task} has '
'status ${record.taskStatus} and progress ${record.progress}'
You can interact with the database
using allRecords
, recordForId
, deleteAllRecords
, deleteRecordWithId
etc. Note that only tasks that you asked to be tracked (using trackTasks
, which activates tracking for all tasks in a group) will be in the database. All active tasks in the queue, regardless of tracking, can be queried via the FileDownloader.taskForId
call etc, but those will only return the task itself, not its status or progress, as those are expected to be monitored via listener or callback. Note: tasks that are started using download
, upload
, batchDownload
or batchUpload
are assigned a special group name 'await', as callbacks for these tasks are handled within the FileDownloader
. If you want to track those tasks in the database, call FileDownloader().trackTasks(FileDownloader.awaitGroup)
at the start of your app.
4.0.0 #
Adds support for MacOS, Windows and Linux and refactored the backend to be more easily extensible.
Changes FileDownloader usage from static to a singleton. This means that instead of calling
FileDownloader.downloader(...)
now call FileDownloader().downloader(...)
etc.
Calling .initialize
is not longer required.
3.0.1 #
iOS BaseDirectory.applicationSupport now uses iOS applicationSupportDirectory instead of libraryDirectory
3.0.0 #
Version 3 introduces uploads, onProgress
and onStatus
callbacks passed to download
and upload
,
and cleans up the API to be less verbose.
The class hierarchy is Request
-> Task
-> (DownloadTask
| UploadTask
), and several
methods and callbacks will return or expect a Task
that may be a DownloadTask
or UploadTask
.
To align naming convention, several class and enum names have been changed:
- class BackgroundDownloadTask -> DownloadTask, and field progressUpdates -> updates
- enum DownloadTaskStatus -> TaskStatus
- enum DownloadProgressUpdates -> Updates (and enum value changes)
- class BackgroundDownloadEvent -> TaskUpdate
- class BackgroundDownloadStatusEvent -> TaskStatusUpdate
- class BackgroundDownloadProgressEvent -> TaskProgressUpdate
- typedef DownloadStatusCallback -> TaskStatusCallback
- typedef DownloadProgressCallback -> TaskProgressCallback
- class DownloadBatch -> Batch
- typedef BatchDownloadProgressCallback -> BatchProgressCallback
2.1.1 #
The url and urlQueryParameters passed to a BackgroundDownloadTask
or Request
must be encoded if necessary. For example, if the url or query parameters contain a space, it must be replaced with %20 per urlencoding
2.1.0 #
Changes:
- Added option to use a POST request: setting the
post
field to a String or UInt8List passes that data to the server using the POST method to obtain your file - Added
request
method, taking aRequest
object (a superclass ofBackgroundDownloadTask
), for simple server requests, where you process the server response directly (i.e. not in a file). - Refactored Android Kotlin code and made small improvement to the fix for issue with
Firebase plugin
onMethodCall
handler
2.0.0 #
Added option to automatically retry failed downloads. This is a breaking change, though for most existing implementations no or very little change is required.
The main change is the addition of enqueued
and waitingToRetry
status to the
DownloadTaskStatus
enum (and removal of undefined
). As a result, when checking a
DownloadStatusUpdate
(e.g. using a switch
statement) you need to cover these new cases (and
for existing implementations can typically just ignore them). The progressUpdate equivalent of
waitingToRetry
is a value of -4.0, but for existing implementations this will never be
emitted, as they won't have retries.
The second change is that a task now emits enqueued
when enqueued, and running
once the actual
download (on the native platform) starts. In existing applications this can generally be ignored,
but it allows for more precise status updates.
To use automatic retries, simply set the retries
field of the BackgroundDownloadTask
to an
integer between 0 and 10. A normal download (without the need for retries) will follow status
updates from enqueued
-> running
-> complete
(or notFound
). If retries
has been set and
the task fails, the sequence will be enqueued
-> running
->
waitingToRetry
-> enqueued
-> running
-> complete
(if the second try succeeds, or more
retries if needed).
1.6.0 #
Added option to set requiresWiFi
on the BackgroundDownloadTask
, which ensures the task won't
start downloading unless a WiFi network is available. By default requiresWiFi
is false, and
downloads will use the cellular (or metered) network if WiFi is not available, which may incur cost.
1.5.0 #
Added allTasks
method to get a list of running tasks. Use allTaskIds
to get a list of taskIds
only.
1.4.2 #
Added note to README referring to an issue ( and fix) where the firebase plugin interferes with the downloader
1.4.1 #
Improved example app, updated documentation and fixed minor Android bug
1.4.0 #
Added downloadBatch
method to enqueue and wait for completion of a batch of downloads
1.3.0 #
Added option to use an event listener instead of (or in addition to) callbacks
1.2.0 #
Added FileDownloader.download as a convenience method for simple downloads. This method's Future completes only after the download has completed or failed, and can be used for simple downloads where status and progress checking is not required.
1.1.0 #
Added headers and metaData fields to the BackgroundDownloadTask. Headers will be added to the request, and metaData is ignored but may be helpful to the user
1.0.2 #
Replaced Ktor client with a basic Kotlin implementation
1.0.0 #
Initial release