LCN Registry

Open React hooks distributed as a shadcn custom registry.

The first registry item, lifecycle-effects, installs explicit React 19+ effect hooks into your project's configured hooks directory.

Install

Install directly from the public registry item:

npx shadcn@latest add https://raw.githubusercontent.com/laststance/lcn-registry/main/public/r/lifecycle-effects.json

Or register a namespace in components.json:

{
  "registries": {
    "@lcn-registry": "https://raw.githubusercontent.com/laststance/lcn-registry/main/public/r/{name}.json"
  }
}

Then install by name:

npx shadcn@latest add @lcn-registry/lifecycle-effects

Before installing, inspect the exact code payload:

npx shadcn@latest view https://raw.githubusercontent.com/laststance/lcn-registry/main/public/r/lifecycle-effects.json

Lifecycle Effects

lifecycle-effects adds:

• useInitialEffect: mount-only effects.
• useUpdateEffect: post-mount update effects, with empty deps rejected at the type level.
• useUnmountEffect: unmount-only cleanup using React 19 useEffectEvent.
• useRenderEffect: every render, or mount plus non-empty dependency changes.
• useCycleEffect: a semantic alias for useEffect.

React 19+ is required because useUnmountEffect and useUpdateEffect use useEffectEvent to call the latest callback without forcing dependency churn.

Development

pnpm install
pnpm registry:build
pnpm registry:check
pnpm typecheck
pnpm validate

The generated registry item lives in public/r/lifecycle-effects.json. Review that JSON in pull requests because it is the exact payload consumed by the shadcn CLI.