isolate_channel

Communication channels for isolates based on Flutter's platform channels

Features

• Helper functions to spawn, setup, and connect to isolates
• Method channels for making method calls to an isolate and receiving the result
• Event channels for receiving streamed events from an isolate

Usage

In the parent isolate, use the spawnIsolate function to spawn a new isolate and connect to it

final connection = await spawnIsolate(isolateEntryPoint);
                

In the newly spawned isolate, use the setupIsolate function to set up the isolate for channel communication

void isolateEntryPoint(SendPort? send) {
                  final connection = setupIsolate(send);
                }
                

Now create communication channels in both isolates

final methodChannel = IsolateMethodChannel('method_channel', connection);
                final eventChannel = IsolateEventChannel('event_channel', connection);
                

Set up handlers for the channels in the newly spawned isolate

methodChannel.setMethodCallHandler((call) {
                  switch (call.method) {
                    case 'example_method':
                      print(call.arguments);
                      return 'World!';
                    default:
                      return call.notImplemented();
                  }
                });
                
                eventChannel.setStreamHandler(
                  IsolateStreamHandler.inline(
                    onListen: (arguments, sink) {
                      sink.success(arguments);
                      sink.error(
                        code: 'error',
                        message: 'Something went wrong',
                        details: 1234,
                      );
                      sink.endOfStream();
                    },
                    onCancel: (arguments) => print('Canceled: $arguments'),
                  ),
                );
                

Now you can use the channels to communicate

final result = await methodChannel.invokeMethod('example_method', 'Hello');
                final stream = eventChannel.receiveBroadcastStream();
                

And close the connection when you're done

connection.close();
                

Connect to a running isolate

Pass an isolate's send port to the connectToIsolate function to connect to it. A send port can be retrieved from an IsolateNameServer.

final connection = await connectToIsolate(send);
                

0.6.1

• Fixes README

0.6.0

• Adds onSendPortReady in setupIsolate to support headless restarts
• The IsolateEntryPoint and setupIsolate functions now accept a nullable send parameter to support headless restarts
• The connectToIsolate function now supports onExit and onError callback setup

0.5.0

• Exposes the spawnIsolateConnection function that allows connecting to custom isolates
• Removes the spawn parameters from the spawnIsolate and spawnUriIsolate functions

0.4.2

• Updates README to reflect that connectToIsolate returns a Future

0.4.1

• Loosens constraint on meta

0.4.0

• Allows passing an IsolateSpawner to support custom isolate implementations such as FlutterIsolate
• Makes connectToIsolate return a Future so that connection failure can be handled

0.3.0

• Removes unnecessary type parameters from spawn methods

0.2.2+1

• Adds README badges

0.2.2

• Handles more edge cases in IsolateEventChannel

0.2.1

• Does not cancel handler subscription when onCancel is called in IsolateEventChannel

0.2.0

• BREAKING: Refactors IsolateException.notImplemented(...) into call.notImplemented()
• Supports communication between isolates spawned with Isolate.spawnUri
• EventChannel optimizations

0.1.1

• Handles exceptions thrown in method call handlers

0.1.0

• Initial release