qcast-front/.agents/skills/vercel-react-best-practices/rules/rendering-activity.md

title	impact	impactDescription	tags
Use Activity Component for Show/Hide	MEDIUM	preserves state/DOM	rendering, activity, visibility, state-preservation

Use Activity Component for Show/Hide

Use React's <Activity> to preserve state/DOM for expensive components that frequently toggle visibility.

Usage:

import { Activity } from 'react'

function Dropdown({ isOpen }: Props) {
  return (
    <Activity mode={isOpen ? 'visible' : 'hidden'}>
      <ExpensiveMenu />
    </Activity>
  )
}

Avoids expensive re-renders and state loss.