# XWUILocale Lightweight i18n controller. Fetches per-locale JSON, swaps `` + `` on activation, persists the chosen locale, and exposes a static `t()` helper. One instance per page is enough. ## Basic Usage Mount + use `XWUILocale.t()` for translations. ```example file: examples/BasicUsage.ts html: examples/BasicUsage.html title: Basic Usage description: Mount + use `XWUILocale.t()` for translations. ``` ## Init With Scopes Static `XWUILocale.init({...})` with multiple string scopes (common / crm / etc.). ```example file: examples/InitWithScopes.ts html: examples/InitWithScopes.html title: Init With Scopes description: Static `XWUILocale.init({...})` with multiple string scopes (common / crm / etc.). ``` ## Preloaded RTL Inline English + Arabic files with a runtime switch that flips `` to rtl. ```example file: examples/PreloadedRtl.ts html: examples/PreloadedRtl.html title: Preloaded RTL description: Preloaded locales, RTL direction flip and {{name}} interpolation. ``` ## Plurals And Switch Runtime-registered locales with a language toggle and count-driven pluralization. ```example file: examples/PluralsAndSwitch.ts html: examples/PluralsAndSwitch.html title: Plurals And Switch description: registerLocale + onChange + CLDR plural forms via t({ count }). ``` ## Missing-key machine translation (opt-in) Offline JSON packs remain the source of truth. When a key is missing from the active locale **and** the fallback locale, hosts may install an async provider. `t()` still returns the raw key immediately; the fill merges in the background and fires `xwui-locale-changed` so reactive UI refreshes. ```ts import { XWUILocale, createFreeMissingKeyProvider, } from '@exonware/xwui'; await XWUILocale.init({ basePath: '/locales', fallbackLocale: 'en', missingKeyProvider: createFreeMissingKeyProvider(), // MyMemory → LibreTranslate missingKeyCache: { persist: true, concurrency: 2 }, }); ``` Prefer **build-time** fill of locale JSON for production. Public free endpoints have quotas/CORS/ToS limits; self-hosted LibreTranslate is the production path. Unofficial Google scrape endpoints are not supported. ### Performance / WASM - MT fill + provider response caches use **FastLru** (xwnode algorithm via `createStringLru`) - bounded, O(1), no multi‑MB download. - `localeAccel: true` enables opportunistic **xwsystem** decode for msgpack/cbor locale payloads when that port is already warm. - `localeAccel: { initWasm: true }` eagerly loads system+node - only for apps that already want wasm. Plain JSON packs stay on native `res.json()` (faster than xwjson for kilobyte files; xwjson is not vendored in xwui dist). ```api ```