Hey I cant figure out how to cancel an SSE Stream in my flutter app.
I am using this package to use SSE in my app: https://pub.dev/packages/sse_channel
I feel like it has a major lack in the documentation.
The SSE works fine just don't know how to stop it with a function.
Im using this to start the SSE
channel = SseChannel.connect(Uri.parse(dotenv.env['BASE_URL'] + '/sse/rn-updates'));
and
channel.stream.listen((message) { code... and some other stuff }
that part works but I don't know how to close it.
Tried stuff like this
static void cancelStream() {
if (channel != null)
channel.sink.close()
}
You should create a global var in your class
StreamSubscription? stream;
and assign it to this variable
stream = channel.stream.listen((message) { code... and some other stuff }
and you can use this code to cancel stream
stream?.cancel();
Related
I have video stream in mjpeg format, so I have read and implmented a lot of ways to work with it, but anything of these ways don't meet my requirments (also I was using webView packages, but now we should implement changing screen oreintation feature and webView dosen't have such thing, so I am using Hero animation to make it works, but in that case my urls with video stream open twice. It dosen't work because it has limitation: only one user can watch stream, in other cases stream will be closed).
So I have found the way to play mjepeg video using Kotlin, and read bout MethodChannel in Flutter, I implemented almost everything as it was said in docs, but it still dosen't work.
Native code:
class MainActivity: FlutterActivity() {
private val channel = "com.example.my_app"
private var view: MjpegView? = null
override fun configureFlutterEngine(#NonNull flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, channel).setMethodCallHandler {
call, result ->
if(call.method == "Video") {
view = findViewById(R.id.mjpegid)
view!!.isAdjustHeight = true
view!!.mode1 = MjpegView.MODE_FIT_WIDTH
view!!.setUrl("http://videos/videos/LiveViewCamera")
view!!.isRecycleBitmap1 = true
result.success("it successed!")
}
else {
result.notImplemented()
}
}
}
}
in Flutter:
final channel = MethodChannel('com.example.my_app');
String videos = '';
Future getVideoFromNative() async {
videos = await channel.invokeMethod('Video');
print(videos);
print('are you hehe?');
setState(() {});
}
Got this error:
E/MethodChannel#com.example.rosysk_nano_cleaned(17621): Failed to handle method call
E/MethodChannel#com.example.rosysk_nano_cleaned(17621): java.lang.NullPointerException
When I open it in pure Kotlin app, my video and code works perfectly fine
Chatting was working perfectly before migrating to null safety using signalr. But after migrating It is not working in chatting part.
Scenario is like there are 2 screens where I am using signalr.
1)Chatlist.
2)Chatting with person.
listener in Chatlist is perfect but in 2nd screen it is not working(Just worked when I installed and run for the 1st time). Weird issue.
All was working in old. I am using bloc for statemanagement and also migrated to yield to emit.
Piece of code is like:
void listenOnMessageReceived(
HubConnection hubConnection,
Function(Message? chatMessageReceive) onMessageReceived,
) {
final SocketResponseCallBack chatMessageReceived =
(response) => onMessageReceived(Message.fromJson(response));
final hubMethod = HubMethod(
CHAT_RECEIVED_MESSAGE_METHOD_NAME,
SignalRHelper.toSocketFunction(
CHAT_RECEIVED_MESSAGE_METHOD_NAME, chatMessageReceived));
bool exists = listenOnHubMethod.any((method) => method.methodName == CHAT_RECEIVED_MESSAGE_METHOD_NAME);
if(exists) {
listenOnHubMethod.removeWhere((element) =>
element.methodName == CHAT_RECEIVED_MESSAGE_METHOD_NAME);
SignalRHelper(hubConnection: hubConnection).on(
hubMethod.methodName,
hubMethod.methodFunction,
);
listenOnHubMethod.add(hubMethod);
}else{
SignalRHelper(hubConnection: hubConnection).on(
hubMethod.methodName,
hubMethod.methodFunction,
);
listenOnHubMethod.add(hubMethod);
}
}
I am having 2 types of above code in different screens. but it is working in only 1 screen and not listening in 2nd screen.
here is a piece of signalr listener code:
static MethodInvocationFunc toSocketFunction(
String methodName, SocketResponseCallBack responseCallBack) {
return (arguments) {
try {
if (arguments!.isEmpty) {
throw SocketEmptyResponseException(methodName);
}
final response = arguments.first;
responseCallBack(response);
} on FormatException {
throw SocketResponseException(methodName);
}
};
}
Is there any limitations in migration of stable version or anything else. Every help is appreciable.
Thank you.
Do not use signalR, on IOS it will be impossible to run listener on background or when app is closed and you will miss messages. Use FCM.
I'm making a Flutter Web App which has to access the microphone and streams the audio data as an array of integers for further processing.
I already succeeded doing this in plain JavaScript.
Things I've tried:
The flutter_sound library, but I couldn't get it to work. I also can't find any working examples for that library.
dart:web_audio seems to be a thing, but apparently you can't even import it yet in normal Flutter Apps.
dart:js is what im trying to do right now. I was able to create an AudioContext with var audioContext = JsObject(context['AudioContext']);. However, after that I dont know what syntax can be used to transfer the JavaScript code into Dart. Here is what I'm doing in JavaScript:
function initAudio() {
try {
audioCtx = new AudioContext();
const GotAudioStream = function(stream) {
const audioSource = audioCtx.createMediaStreamSource(stream);
const audioProcessor = audioCtx.createScriptProcessor(bufSize, 1, 1);
audioSource.connect(audioProcessor);
audioProcessor.connect(audioCtx.destination);
audioStarted = true;
audioProcessor.onaudioprocess = function(e) {
checkAudioBuffer(e.inputBuffer);
};
};
navigator.mediaDevices.getUserMedia({ audio: true, video: false }).then(GotAudioStream);
}
catch (err) {
console.log(err);
}
}
Does anyone have experience with the dart:js library or another Idea on how to implement a simple (live!) audio stream in Flutter Web?
Regards,
Kaisky
I am using the flutter-webrtc-plugin and would like to record both local and remote audio streams. Is there any way for me to get audio buffers from the media streams? I have tried using the AudioFileRenderer in the unified-plan branch. In the startRecording function of MediaRecorderImpl.java, I supplied the file storage path e.g. "storage/emulated/0/Android/data", a file is successfully created everytime I ended my call but the recording file is broken so it can't be played. There are no errors coming from the terminal. I'm using flutter v1.22.6 and forked the flutter-webrtc from 0.5.8. I added the AudioFileRenderer file to the flutter-webrtc 0.5.8, my code is as below:
public void startRecording(File file) throws Exception {
recordFile = file;
if (isRunning)
return;
isRunning = true;
//noinspection ResultOfMethodCallIgnored
file.getParentFile().mkdirs();
if (videoTrack != null) {
System.out.println("try123 1");
videoFileRenderer = new VideoFileRenderer(
file.getAbsolutePath(),
EglUtils.getRootEglBaseContext(),
audioInterceptor != null
);
videoTrack.addSink(videoFileRenderer);
if (audioInterceptor != null)
audioInterceptor.attachCallback(id, videoFileRenderer);
} else {
Log.e(TAG, "Video track is null");
if (audioInterceptor != null) {
//TODO(rostopira): audio only recording
// throw new Exception("Audio-only recording not implemented yet");
Log.d(TAG, "Try to use onWebrtcSamplesReady");
audioFileRenderer = new AudioFileRenderer(file);
audioInterceptor.attachCallback(id, audioFileRenderer);
}
}
}
Any help is appreciated! Thanks!
I am also looking for the same solution, none has been found so far.
So, I am using webview for the the RTC part (communication & recording), while keeping the Firebase messaging and EventSource/SSE (I'm not using socket) in Flutter.
This is not directly answer your question, just providing alternative solution, it's better than having no solution at all, probably in the future when flutter RTC updated and supporting voice only recording, we can update the apps we develop.
I know these libraries flutter_isolate and isolate_handler exist that support doing these but I couldn't find any method to call platform specific codes from inside of them. Can someone show any example of how it's done ?
My answer might not answer to your question directly but I was facing the same situation.
I was working on this to run a computing intensive task avoiding UI lagging. After a long research, no, you cannot run Platform from other isolates rather than the main one.
Instead of making and running the native code on another isolate, let's make the native code run in background instead with TaskQueue.
Channels and platform threading
The example code in the above link is using onAttachedToEngine, you can check it out. However, I was using is configureFlutterEngine so I have to figure out a little bit until I found a solution that I need binaryMessenger to make it working. Luckily it can called from flutterEngine too!
This is the example code of when using configureFlutterEngine
class MainActivity: FlutterFragmentActivity() {
val MOBILE_SDK_CHANNEL = "com.example.app/flutter"
override fun configureFlutterEngine(#NonNull flutterEngine: FlutterEngine) {
GeneratedPluginRegistrant.registerWith(flutterEngine);
super.configureFlutterEngine(flutterEngine)
val taskQueue = flutterEngine.dartExecutor.binaryMessenger.makeBackgroundTaskQueue()
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, MOBILE_SDK_CHANNEL,
StandardMethodCodec.INSTANCE, taskQueue).setMethodCallHandler { call, result ->
// TODO : Do implementation here
when (call.method) {
"example_method" -> {
// success
// result.success(data)
}
else -> result.notImplemented()
}
}
}
}
With taskQueue the native code will be ready to run in background.
Future<void> getData() async {
if (Platform.isAndroid) {
const platform = MethodChannel("com.example.app/flutter");
var data = await platform.invokeMethod("example_method");
// data is ready to use and non-blocked the UI thread
return data
}
}
The native code now runs in non-blocking manner, no more UI lag. :)