Presence

在频道内同步在线状态。添加 .on("presence", ...) 后会自动开启接收；track() 会让其他已开启 Presence 的订阅者看到自己。

const channel = realtime.channel("presence-test", {
  config: {
    presence: { key: "user-1" },
  },
});

channel.on("presence", { event: "sync" }, () => {
  console.log("在线用户", channel.presenceState());
});

channel.on("presence", { event: "join" }, ({ newPresences }) => {
  console.log("加入", newPresences);
});

channel.on("presence", { event: "leave" }, ({ leftPresences }) => {
  console.log("离开", leftPresences);
});

channel.subscribe(async (status) => {
  if (status !== "SUBSCRIBED") return;
  await channel.track({ user_id: 1, name: "Ada" });
});

提示

config.presence.enabled（或添加 Presence 监听）只控制本端是否接收他人状态；不影响 track() 是否对他人可见。未开启时，本端 presenceState() 为空。