48 lines
1.3 KiB
TypeScript
48 lines
1.3 KiB
TypeScript
// Copyright 2017-2020 @polkadot/react-components authors & contributors
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// SPDX-License-Identifier: Apache-2.0
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import languageCache from './cache';
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type Callback = (error: string | null, data: any) => void;
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type LoadResult = [string | null, Record<string, string> | boolean];
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const loaders: Record<string, Promise<LoadResult>> = {};
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export default class Backend {
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type = 'backend'
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static type: 'backend' = 'backend'
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async read (lng: string, _namespace: string, responder: Callback): Promise<void> {
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if (languageCache[lng]) {
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return responder(null, languageCache[lng]);
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}
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// eslint-disable-next-line @typescript-eslint/no-misused-promises
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if (!loaders[lng]) {
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loaders[lng] = this.createLoader(lng);
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}
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const [error, data] = await loaders[lng];
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return responder(error, data);
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}
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async createLoader (lng: string): Promise<LoadResult> {
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try {
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const response = await fetch(`locales/${lng}/translation.json`, {});
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if (!response.ok) {
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return [`i18n: failed loading ${lng}`, response.status >= 500 && response.status < 600];
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} else {
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languageCache[lng] = await response.json() as Record<string, string>;
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return [null, languageCache[lng]];
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}
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} catch (error) {
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return [(error as Error).message, false];
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}
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}
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}
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