Broadcast

按 event 收发瞬时消息。默认不回传自己发出的消息，也不等待服务端确认。

const channel = realtime.channel("broadcast-test", {
  config: {
    broadcast: { ack: false, self: false },
  },
});

channel.on("broadcast", { event: "some-event" }, (payload) => {
  console.log(payload);
});

channel.subscribe(async (status) => {
  if (status !== "SUBSCRIBED") return;
  await channel.send({
    type: "broadcast",
    event: "some-event",
    payload: { hello: "world" },
  });
});

选项	说明
ack	true 时 send() 会等服务端确认后再 resolve
self	true 时发送方也会收到自己发出的消息
replay	仅私有频道可用。按 since（毫秒时间戳）回放历史 Broadcast，可选 limit（最大 25）

const twelveHoursAgo = Date.now() - 12 * 60 * 60 * 1000;

const channel = realtime.channel("main:room", {
  config: {
    private: true,
    broadcast: { replay: { since: twelveHoursAgo, limit: 10 } },
  },
});

channel.on("broadcast", { event: "my_event" }, (payload) => {
  if (payload?.meta?.replayed) {
    console.log("历史消息", payload);
  } else {
    console.log("新消息", payload);
  }
});
channel.subscribe();

未建立 WebSocket 时，send() 会回退到 HTTP；需要显式走 HTTP 时请用 httpSend()。