useSubscribeCallback

useSubscribeCallback returns a stable subscribe function you can call imperatively to start a subscription and receive an Unsubscribe function back. Use it when you need to manage the subscription lifetime yourself (e.g. subscribing inside an event handler or effect).

Usage

import { useSubscribeCallback } from "@/components/realtime";
import { useEffect } from "react";
 
function DynamicSubscriber({ topicId }: { topicId: string | null }) {
  const subscribe = useSubscribeCallback();
 
  useEffect(() => {
    if (!topicId) return;
    const unsubscribe = subscribe(`resource/items/${topicId}`, (event) => {
      console.log("item event", event.type);
    });
    return unsubscribe;
  }, [topicId, subscribe]);
 
  return null;
}

Params

None. The hook takes no arguments.

Returns

A stable callback with signature:

(topic: string, callback: SubscriptionCallback) => Unsubscribe

Notes

• The returned function is memoised with useCallback and only changes when the underlying DataProvider instance changes — safe to include in dependency arrays.
• Throws at call time (not at hook call time) if the DataProvider does not implement subscribe().
• Prefer useSubscribe for component-lifetime subscriptions. Use useSubscribeCallback only when you need manual control over when the subscription starts and ends.