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Dart - websocket.send()

Send a message to a connected websocket client.

import 'package:nitric_sdk/nitric.dart';

final socket = Nitric.websocket("socket");

await socket.send(connectionId, message);

Parameters

  • Name
    connectionId
    Required
    Required
    Type
    String
    Description

    The ID of the connection which should receive the message.

  • Name
    message
    Required
    Required
    Type
    Map<String, dynamic>
    Description

    The message that should be sent to the connection.

Examples

Broadcasting a message to all connections.

Do not send messages to a connection during it's connect callback, if you need to acknowledge connection, do so by using a topic

import 'package:nitric_sdk/nitric.dart';

final socket = Nitric.websocket("socket");
final connections = Nitric.kv("connections").allow([
  KeyValueStorePermission.get,
  KeyValueStorePermission.set,
  KeyValueStorePermission.delete,
]);

socket.onConnect((ctx) async {
  await connections.set(ctx.req.connectionId, {
    // add metadata
    "creation_time": DateTime.now(),
  });

  return ctx;
});

socket.onDisconnect((ctx) async {
  await connections.delete(ctx.req.connectionId);
});

// broadcast message to all clients (including the sender)
socket.onMessage((ctx) async {
  final conns = await connections.keys();

  await Future.wait(await conns.map((conn) async {
    // Send a message to a connection
    return socket.send(conn, ctx.req.message);
  }).toList());

  return ctx;
});