background_location_tracker

A new Flutter plugin that allows you to track the background location for Android & iOS

Android Config

Update compile sdk

Compile sdk should be at 29 at least.

android {
  ...
  compileSdkVersion 29
  ...

  defaultConfig {
    ...
    targetSdkVersion 29
    ...
  }
  ...
}

iOS Configuration

Update Info.plist

Add the correct permission descriptions

	<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
	<string>Your description why you should use NSLocationAlwaysAndWhenInUseUsageDescription</string>
	<key>NSLocationAlwaysUsageDescription</key>
	<string>Your description why you should use NSLocationAlwaysAndWhenInUseUsageDescription</string>
	<key>NSLocationWhenInUseUsageDescription</key>
	<string>Your description why you should use NSLocationAlwaysAndWhenInUseUsageDescription</string>

Add the background location updates in xcode

Or add the info to the Info.plist

	<key>UIBackgroundModes</key>
	<array>
		<string>location</string>
	</array>

Update the AppDelegate

Make sure you call the setPluginRegistrantCallback so other plugins can be accessed in the background.

import UIKit
import Flutter
import background_location_tracker

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
    override func application(_ application: UIApplication,didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        GeneratedPluginRegistrant.register(with: self)

        BackgroundLocationTrackerPlugin.setPluginRegistrantCallback { registry in
            GeneratedPluginRegistrant.register(with: registry)
        }

        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }
}

Flutter implementation

Make sure you set the @pragma('vm:entry-point') to make sure you can find the callback in release.

@pragma('vm:entry-point')
void backgroundCallback() {
  BackgroundLocationTrackerManager.handleBackgroundUpdated(
    (data) async => Repo().update(data),
  );
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await BackgroundLocationTrackerManager.initialize(
    backgroundCallback,
    config: const BackgroundLocationTrackerConfig(
      loggingEnabled: true,
      androidConfig: AndroidConfig(
        notificationIcon: 'explore',
        trackingInterval: Duration(seconds: 4),
        distanceFilterMeters: null,
      ),
      iOSConfig: IOSConfig(
        activityType: ActivityType.FITNESS,
        distanceFilterMeters: null,
        restartAfterKill: true,
      ),
    ),
  );

  runApp(MyApp());
}

Future startLocationTracking() async {
  await BackgroundLocationTrackerManager.startTracking();
}

Future stopLocationTracking() async {
  await BackgroundLocationTrackerManager.stopTracking();
}

FAQ:

I get a Unhandled Exception: MissingPluginException(No implementation found for method .... on channel ...)

This is mostly caused by a misconfiguration of the plugin:
Android Pre v2 embedding: make sure the plugin registrant callback is set
Android v2 embedding: Log a new github issues. This
iOS: make sure the plugin registrant callback is set

Libraries

background_location_tracker