This plugin provides a file upload functionality that can continue to run even while the app is in background. It includes progress updates suitable for long-term transfer operations of large files.
Supported Platforms
- iOS
- Android
Installation
To install the plugin:
cordova plugin add @spoonconsulting/cordova-plugin-background-upload --save
To uninstall this plugin:
cordova plugin rm @spoonconsulting/cordova-plugin-background-upload
Sample usage
The plugin needs to be initialised before any upload. Ideally this should be called on application start. The uploader will provide global events which can be used to check the progress of the uploads. By default, the maximum number of parallel uploads allowed is set to 1. You can override it by changing the configuration on init.
var FileTransferManager: any;
var config = {};
var uploader = FileTransferManager.init(config, callback);Configuration Options
| Option | Availability | Purpose |
|---|---|---|
| parallelUploadsLimit | iOS, Android | Sets the number of simultaneous uploads. |
| resourceTimeout | iOS | How long a given resource will retry until it fails. |
| requestTimeout | iOS | How long an individual attempt will wait until it fails to retry again later. |
Methods
Initialises the uploader with provided configuration. To control the number of parallel uploads,
pass parallelUploadsLimit in config.
The callback is used to track progress of the uploads
var uploader = FileTransferManager.init({parallelUploadsLimit: 2}, event => {});
Adds an upload. In case the plugin was not able to enqueue the upload, an error will be emitted in the global event listener.
var payload = {
id: "c3a4b4c7-4f1e-4c69-a951-773602e269fb",
filePath: "/storage/emulated/0/Download/Heli.divx",
fileKey: "file",
serverUrl: "http://requestb.in/14cizzj1",
notificationTitle: "Uploading images",
headers: {
api_key: "asdasdwere123sad"
},
parameters: {
signature: "a_signature_hash",
timestamp: 112321321
}
};
uploader.startUpload(payload);| Param | Description |
|---|---|
| id | a unique id of the file (UUID string) |
| filePath | the absolute path for the file to upload |
| fileKey | the name of the key to use for the file |
| serverUrl | remote server url |
| headers | custom http headers |
| parameters | custom parameters for multipart data |
| notificationTitle | Notification title when file is being uploaded (Android only) |
Cancels and removes an upload
uploader.removeUpload(uploadId, function () {
//upload aborted
}, function (err) {
//could not abort the upload
});Confirms event received and remove it from plugin cache
uploader.acknowledgeEvent(eventId);The uploader will provide global events which can be used to check the status of the uploads.
FileTransferManager.init({}, function (event) {
if (event.state == 'UPLOADED') {
console.log("upload: " + event.id + " has been completed successfully");
console.log(event.statusCode, event.serverResponse);
} else if (event.state == 'FAILED') {
if (event.id) {
console.log("upload: " + event.id + " has failed");
} else {
console.error("uploader caught an error: " + event.error);
}
} else if (event.state == 'UPLOADING') {
console.log("uploading: " + event.id + " progress: " + event.progress + "%");
}
});To prevent any event loss while transitioning between native and Javascript side, the plugin stores success/failure events on disk. Once you have received the event, you will need to acknowledge it else it will be broadcast again when the plugin is initialised. Progress events do not have eventId and are not persisted.
if (event.eventId) {
uploader.acknowledgeEvent(event.eventId, function () {
//success
}, function (error) {
//error
});
}An event has the following attributes:
| Property | Comment |
|---|---|
| id | id of the upload |
| state | state of the upload (either UPLOADING, UPLOADED or FAILED) |
| statusCode | response code returned by server after upload is completed |
| serverResponse | server response received after upload is completed |
| error | error message in case of failure |
| errorCode | error code for any exception encountered |
| progress | progress for ongoing upload |
| eventId | id of the event |
The plugin runs on ios 10.0 and above and internally uses AFNetworking. AFNetworking uses NSURLSession under the hood to perform the upload in a background session. When an upload is initiated, it will continue until it has been completed successfully or until the user kills the application. If the application is terminated by the OS, the uploads will still continue. When the user relaunches the application, after calling the init method, events will be emitted with the ids of these uploads. If the user kills the application by swiping it up from the multitasking pane, the uploads will not be continued. Upload tasks in background sessions are automatically retried by the URL loading system after network errors as decided by the OS.
The minimum API level required is 21(Android 5) and the background file upload is handled by the WorkMananger library. If you have configured a notification to appear in the notifications area, the uploads will continue even if the user kills the app manually. If an upload is added when there is no network connection, it will be retried as soon as the network becomes reachable unless the app has already been killed.
On Android 12 and above, there are strict limitations on background services that does not allow to start a Foreground Service when the app is processing in background(https://developer.android.com/guide/components/foreground-services). Hence to prevent this on Android 12 and above, we have a classic notification. On Android 11 and below, we are still using foreground service along with WorkManager to start the notification.
- When v2 of the plugin is launched on an app containing uploads still in progress from v1 version, it will mark all of
them as
FAILEDwitherrorCode500 so that they can be retried. - If an upload is cancelled, an event with status
FAILEDand error code-999will be broadcasted in the global callback. It is up to the application to properly handle cancelled callbacks. - v2 removes the events
success,error,progressand instead uses a single callback for all events delivery:uploader.on('event', function (event) { //use event.state to handle different scenarios });
- Events need to be acknowledged to be removed. Failure to do so will result in all saved events being broadcast
on
init. -showNotificationparameter has been removed (A notification will always be shown on Android during upload)
The README for the previous version can be found here.
cordova-plugin-background-upload is licensed under the Apache v2 License.
cordova-plugin-background-upload is brought to you by [Spoon Consulting Ltd] (http://www.spoonconsulting.com/).