Polling for live data

Problem. Refresh a dashboard widget every few seconds without manual setInterval bookkeeping.

Solution. Use usePolling — it pauses on tab hidden, resumes on focus, and exposes a dispose() for teardown.

import { effect, usePolling } from '@bquery/bquery/reactive';

const stats = usePolling(
  async () => {
    const r = await fetch('/api/stats');
    if (!r.ok) throw new Error('failed');
    return r.json();
  },
  { interval: 5_000, immediate: true, pauseOnHidden: true }
);

effect(() => {
  const nextStats = stats.data.value;
  if (nextStats) render(nextStats);
});
// later: stats.dispose();

Why it works. usePolling listens to document.visibilitychange to avoid wasting requests, and the returned data / error / isActive are signals you can bind directly to your view.

Related

• Reactive — Polling helpers
• Reactive — useResource
• Longer worked example: Examples & Recipes — Polling for live data