@react-aria/i18n/src/useLocalizedStringFormatter.ts

Spectrum UI components in React

/*
 * Copyright 2022 Adobe. All rights reserved.
 * This file is licensed to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under
 * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

import {LocalizedString, LocalizedStringDictionary, LocalizedStringFormatter, LocalizedStrings} from '@internationalized/string';
import {useLocale} from './context';
import {useMemo} from 'react';

const cache = new WeakMap();
function getCachedDictionary<K extends string, T extends LocalizedString>(strings: LocalizedStrings<K, T>): LocalizedStringDictionary<K, T> {
  let dictionary = cache.get(strings);
  if (!dictionary) {
    dictionary = new LocalizedStringDictionary(strings);
    cache.set(strings, dictionary);
  }

  return dictionary;
}

/**
 * Provides localized string formatting for the current locale. Supports interpolating variables,
 * selecting the correct pluralization, and formatting numbers. Automatically updates when the locale changes.
 * @param strings - A mapping of languages to localized strings by key.
 */
export function useLocalizedStringFormatter<K extends string = string, T extends LocalizedString = string>(strings: LocalizedStrings<K, T>): LocalizedStringFormatter<K, T> {
  let {locale} = useLocale();
  let dictionary = useMemo(() => getCachedDictionary(strings), [strings]);
  return useMemo(() => new LocalizedStringFormatter(locale, dictionary), [locale, dictionary]);
}