Conas a chinneann tú cá ar cheart do gach píosa staid a bheith ina chónaí?

Question

Accepted Answer

Is é a bheith ag cinneadh **cá bhfuil an staid ina cónaí** ar cheann de na scileanna ailtireachta is tábhachtaí. An prionsabal treorach: cuir gach píosa staid sa **scóip is cúinge** atá ann fós agus a shásann gach duine atá i ndiaidh a bheith ann — agus bain gach *cineál* de staid a mheaitsiú don uirlis cheart.

## Creat cinneadh

```text
1. Who needs this state?
   - One component                  → local state (useState)
   - A few related components        → lift to common parent / small context
   - Many distant components         → global store or context

2. What KIND of state is it?
   - Server/remote data              → server-state library (React Query/SWR)
   - UI/client state                 → useState / Zustand / Redux
   - URL-derivable (filters, page)    → the URL (searchParams)
   - Form input                       → form library or local state

3. How OFTEN does it change?
   - Rarely, widely shared (theme)    → Context is fine
   - Frequently, widely shared        → store with selective subscriptions
```

## Na catagóirí agus a dtithe

```text
State type     Lives in                       Examples
─────────────────────────────────────────────────────────────────
Local UI       component (useState)           input text, isOpen, hover
Shared UI      lifted parent / Context / store modal state, selected item
Server data    React Query / SWR / RTK Query  users, products (cached remote)
URL state      router / searchParams          filters, page, search query, tab
Form state     React Hook Form / local         field values, validation
Global app     Zustand / Redux / Context      auth user, theme, cart
```

## Botúin choitianta a bhíonn an creat ag cosc

```text
❌ Server data in Redux       → use React Query (it's a cache, not UI state)
❌ Everything global "just in case" → over-coupling, extra re-renders; keep local
❌ Filters/page in state       → put in the URL (shareable, bookmarkable, back-button)
❌ Duplicating derivable values → derive instead (single source of truth)
❌ Form state in a global store → usually overkill; keep local or use a form lib
```

## An URL — staid atá gan úsáid a dhóthain

```text
Filters, pagination, search, active tab → belong in the URL.
Benefits: shareable links, browser back/forward works, survives refresh, SEO.
```

## Cén fáth a bhíonn sé tábhachtach

Déanann áit a bhfuil an staid ina cónaí a chinneadh ar shimplíce, ar fheidhmíochta, agus ar inoibritheachta an aip.

Is é an scil a bheith ag foluain i gcoinne an dúil a bheith ag déanamh gach rud domhanda agus ina áit sin **a bheith ag foluain ar bhealach logánta, gach cineál staid a mheaitsiú dá uirlis cheart** (sonraí freastalaí → React Query, infhillithe URL → an URL, UI → áitiúil/stór).

Má fhaigheann tú seo i gceart, seachnaíonn sé na fadhbanna ailtireachta is coitianta — sonraí freastalaí brúite isteach i Redux, staid róghlobálaithe ag cur faoi do athrá, agus scagachán i staid an chomhpháirt in ionad an URL.

Is é an bhreithiúnas seo an rud a dhéanann idirdhealú idir ailtireacht staid gheal, inréadta agus ceann foluain, tanglaithe.