[Issue]: Missing Plugin exception when the app is in background. Using home screen widget to start the scan about flutter_blue_plus

[chipweinberger]

flutterHotRestart is called during any fbp launch, not just hot restart.

edit: just now, in this commit (29561d5) i renamed it to flutterRestart

[chipweinberger]

did you look here: https://github.com/boskokg/flutter_blue_plus?tab=readme-ov-file#missingpluginexceptionno-implementation-found-for-method-xxxx-

---

MissingPluginException(No implementation found for method XXXX ...)

If you just added flutter_blue_plus to your pubspec.yaml, a hot reload / hot restart is not enough.

You need to fully stop your app and run again so that the native plugins are loaded.

Also try flutter clean.

[rohanots]

Yes Sir, I did. Actually, this is happening because the invoke method is unable to perform a hot restart since the app is is in background.

Why my app is in background?
Because I am using home screen widget flutter and starting the BLE scan from there.

Log:
MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:332:7)
No implementation found for method flutterHotRestart

[rohanots]

Is there any way we can scan and connect nearby BLE devices with iOS devices while the app is in background.

[chipweinberger]

yes. implement this PR: #846

pauldemarco/flutter_blue#210

[chipweinberger]

I cannot reproduce this problem btw. Starting from home screen works for me.

[rohanots]

This is how I am doing this. The app is background/killed. A user can quickly connect with BT device from the widget outside without opening the app.

Using the home_widget package.
Code on button clicks.
@pragma('vm:entry-point') Future<void> interactiveCallback(Uri? uri) async { // Set AppGroup Id. This is needed for iOS Apps to talk to their WidgetExtensions await HomeWidget.setAppGroupId(Constants.appGroupId); print("interactiveCallback ${uri?.host}"); // We check the host of the uri to determine which action should be triggered. if (uri?.host == 'increment') { await connectBTDevice(); } else if (uri?.host == 'unlock') { await unlockDevice(); } }

`connectBTDevice(){
FlutterBluePlus.startScan(
timeout: const Duration(seconds: 3),
);

 for (var btDevice in scanResults) {
          if (btDevice.advertisementData.advName.split('-').last ==
              tempDeviceId) {
              await btDevice.connect();
  }       

}
`

[chipweinberger]

Ah, I did not understand what you meant by Home Screen Widget. Thank you for the screenshot.

This is not something I know how to fix. Sorry. If you fix it, please open PR.

My guess is that the problem must be fixed in the home_widget package, not fbp

[rohanots]

No i have not been able to fix this yet.
Thanks for your replies and the quick support.