Using onesignal push notifications without backend server

Hello,

You can use onesignal service to send push notifications without using an external server or backend server directly from the mobile app for example, I know it's not the best solution but you can manage to make it work in small apps.

the code below is an example of flutter code:

sendAdNotification() async {
     OneSignal.shared.getPermissionSubscriptionState();
     OneSignal.shared.getDeviceState().then((deviceState) {
       print("OneSignal: device state: ${deviceState?.userId}");
     });

     var sendData = await post(
       Uri.parse('https://onesignal.com/api/v1/notifications'),
       headers: <String, String>{
         'Content-Type': 'application/json; charset=UTF-8',
         'Authorization': 'Basic RESTAPIKEY',
       },
       body: jsonEncode(<String, dynamic>
       {
         "app_id": "APPID",//kAppId is the App Id that one get from the OneSignal When the application is registered.

         "filters": [
           {"field": "tag", "key": "KeyNAme", "relation": "=", "value": Id},

         ],
         "android_accent_color":"FF9976D2",

         "small_icon":"ic_stat_onesignal_default",

         "large_icon":"biglogo.png",

         "headings": {"en": "New Ad"},

         "contents": {"en": titleTextEditingController.text},


       }),
     );

     debugPrint(sendData.body.toString());
   }