Closed ashleshp closed 3 years ago
shamblett
commented
3 years ago The client doesn't provide a mechanism for auto connecting on start, you have to create the client and call connect from your code.
From the log output above -
E/flutter (31363): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: NoSuchMethodError: The method 'setAppConnectionState' was called on null.This error is output by flutter, and would seem to be in your code, not the client.
ashleshp
commented
3 years ago As we get appstate once the build is done, Iam not able to call it in "initstate" I have tried asynchronous calls but dont know if its right or wrong . Can you suggest me any idea?
shamblett
commented
3 years ago I'm not a flutter user so I wouldn't know, you are better off asking on a flutter list.
ashleshp
commented
3 years ago Suppose we have a function configureandconnect which connects client to any mqtt endpoint we can call this function in initstate by using PostFrameCallback: `void initState() { super.initState(); WidgetsBinding.instance.addPostFrameCallback((_) => currentAppState.getAppConnectionState==MQTTAppConnectionState.disconnected? _configureAndConnect():null);
}`
IS there a way where we can auto connect to endpoint on app start??? I have tried this and these were my logs**
`class _MQTTViewState extends State {
final TextEditingController _hostTextController = TextEditingController();
final TextEditingController _messageTextController = TextEditingController();
final TextEditingController _topicTextController = TextEditingController();
MQTTAppState currentAppState;
MQTTServerClientManager manager;
final String demoAWSIOTEndpoint =
'a1vh8wv3c2znzr.ats.iot.cn-north-1.amazonaws.com.cn';
final String demoAWSIOTTopic = 'drivingCycleTopic';
final String demoText =
'{"message":"hello from android/ios"}';
@override void initState() { super.initState(); _configureAndConnect(); }
@override void dispose() { _hostTextController.dispose(); _messageTextController.dispose(); _topicTextController.dispose(); super.dispose(); }
@override Widget build(BuildContext context) { final MQTTAppState appState = Provider.of(context);
// Keep a reference to the app state.
currentAppState = appState;
final Scaffold scaffold =
Scaffold(appBar: _buildAppBar(context), body: _buildColumn());
return scaffold;
}
void _configureAndConnect() {
// TODO: Use UUID
String osPrefix = 'Flutter_iOS';
if (Platform.isAndroid) {
osPrefix = 'Flutter_Android';
}
manager = MQTTServerClientManager(
host: "a2qjty4wsdd1fv-ats.iot.ap-south-1.amazonaws.com",
topic: _topicTextController.text,
//host: demoAWSIOTEndpoint,
//topic: demoAWSIOTTopic,
identifier: osPrefix,
state: currentAppState);
manager.initializeMQTTClient();
manager.connect();
}