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();