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Building a geofencing powered live activity

In this tutorial, we show you how to use the Radar flutter SDK and geofences to show a live activity when a user enters a geofence.

In this example, we show live activities on iOS using event listeners.

Languages used#

  • Flutter
  • Swift

Features used#

Steps#

Step 1: Sign up for Radar#

If you haven't already, sign up for Radar to get your API key. You can create up to 1,000 geofences and make up to 100,000 API requests per month for free.

Get API keys

Step 2: Import geofences#

On the Geofences page, create a geofence. It may be useful to assign a specific tag to geofences you hope to power live activities with.

Step 3: Implement live activities#

Implement live activities using the flutter_live_activities library. Their README page contains instructions to set up the widget extension, necessary permissions and the iOS app group. You can also use their example app for reference.

Step 4: Install the Radar flutter SDK#

Follow the installation instructions to add flutter_radar to your project.

Initialize the SDK in your a class that is initialized near the root of the flutter app with your publishable API key.

Also implement the boiler plate setup code for flutter_live_activities

Then, request location permissions and start tracking:

import 'package:flutter_radar/flutter_radar.dart';import 'package:live_activities/live_activities.dart';...
class Home extends StatefulWidget {    const Home({super.key});
    @override    State<Home> createState() => _HomeState();}

class _HomeState extends State<Home> {    final _liveActivitiesPlugin = LiveActivities();
    @override    void initState() {        super.initState();        initRadar();
        _liveActivitiesPlugin.init(appGroupId: 'YOUR_APP_GROUP_ID');        ...    }
    Future<void> initRadar() async {        Radar.initialize('prj_test_pk_...');        Radar.setUserId('YOUR_USER_NAME');        Radar.setDescription('YOUR_USER_DESCRIPTION');
        // optionally implement your own location permissions request flow        await Radar.requestPermissions(false);        await Radar.requestPermissions(true);        var permissionStatus = await Radar.getPermissionsStatus();        if (permissionStatus != "DENIED") {            Radar.startTracking('responsive');        }        }}

Step 5: Listen for events#

Implement onEvents to listen for geofence entry events to control live activities:

class _HomeState extends State<Home> {    ...    @override    void initState() {        super.initState();        initRadar();        ...    }
    @pragma('vm:entry-point')    void onEvents(Map res) async {        if (res.containsKey('events')) {            List events = res['events'];            for (var event in events) {                // start the live activity when we enter the geofence                 if (event['type'] == 'user.entered_geofence' && event['geofence']['tag'] == 'YOUR_TAG_FOR_LIVE_ACTIVITY') {                    if (_latestActivityId == null) {                         // Start a live activity when user enters geofence                        final activityId = await _liveActivitiesPlugin.createActivity({                            'geofenceName': event['geofence']['description'] ?? 'Unknown geofence',                            'enteredAt': DateTime.now().toIso8601String(),                        });                        setState(() => _latestActivityId = activityId);                    } else {                        _liveActivitiesPlugin.updateActivity(                           _latestActivityId!,                           {                                'geofenceName': event['geofence']['description'] ?? 'Unknown geofence',                                'enteredAt': DateTime.now().toIso8601String(),                           }                         );                    }                                   }                if (event['type'] == 'user.exited_geofence' && event['geofence']['tag'] == 'YOUR_TAG_FOR_LIVE_ACTIVITY') {                   _liveActivitiesPlugin.endAllActivities();                    setState(() => _latestActivityId = null);                 }            }       }    }
    Future<void> initRadar() async {        Radar.initialize('prj_test_pk_...');        ...        Radar.onEvents(onEvents);        }}

Step 6: Access geofence information from the live activity widget#

Access the values inside the widget using the shared user defaults.

let geofenceDescription = sharedDefault.string(forKey: context.attributes.prefixedKey("geofenceName"))!let enteredAt = = sharedDefault.string(forKey: context.attributes.prefixedKey("enteredAt"))!

There are may resources that you can reference for implementing the live activity UI, here are some tutorials:

Support#

Have questions or feedback on this documentation? Let us know! Contact us at radar.com/support.