calckey/packages/sw/src/scripts/lang.ts

48 lines
1.2 KiB
TypeScript

/*
* Language manager for SW
*/
declare var self: ServiceWorkerGlobalScope;
import { get, set } from 'idb-keyval';
import { I18n } from '@/scripts/i18n';
class SwLang {
public cacheName = `mk-cache-${_VERSION_}`;
public lang: Promise<string> = get('lang').then(async prelang => {
if (!prelang) return 'en-US';
return prelang;
});
public setLang(newLang: string) {
this.lang = Promise.resolve(newLang);
set('lang', newLang);
return this.fetchLocale();
}
public i18n: Promise<I18n<any>> | null = null;
public fetchLocale() {
return this.i18n = this._fetch();
}
private async _fetch() {
// Service Workerは何度も起動しそのたびにlocaleを読み込むので、CacheStorageを使う
const localeUrl = `/assets/locales/${await this.lang}.${_VERSION_}.json`;
let localeRes = await caches.match(localeUrl);
// _DEV_がtrueの場合は常に最新化
if (!localeRes || _DEV_) {
localeRes = await fetch(localeUrl);
const clone = localeRes?.clone();
if (!clone?.clone().ok) Error('locale fetching error');
caches.open(this.cacheName).then(cache => cache.put(localeUrl, clone));
}
return new I18n(await localeRes.json());
}
}
export const swLang = new SwLang();