signal-desktop/sticker-creator/util/i18n.tsx
2020-11-04 13:03:13 -06:00

82 lines
2.2 KiB
TypeScript

// Copyright 2019-2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import * as React from 'react';
export type I18nFn = (
key: string,
substitutions?: Array<string | number> | ReplacementValuesType
) => string;
export type ReplacementValuesType = {
[key: string]: string | number;
};
const I18nContext = React.createContext<I18nFn>(() => 'NO LOCALE LOADED');
export type I18nProps = {
children: React.ReactNode;
messages: { [key: string]: { message: string } };
};
export const I18n = ({ messages, children }: I18nProps): JSX.Element => {
const getMessage = React.useCallback<I18nFn>(
(key, substitutions) => {
if (Array.isArray(substitutions) && substitutions.length > 1) {
throw new Error(
'Array syntax is not supported with more than one placeholder'
);
}
const { message } = messages[key];
if (!substitutions) {
return message;
}
if (Array.isArray(substitutions)) {
return substitutions.reduce(
(result, substitution) =>
result.toString().replace(/\$.+?\$/, substitution.toString()),
message
) as string;
}
const FIND_REPLACEMENTS = /\$([^$]+)\$/g;
let match = FIND_REPLACEMENTS.exec(message);
let builder = '';
let lastTextIndex = 0;
while (match) {
if (lastTextIndex < match.index) {
builder += message.slice(lastTextIndex, match.index);
}
const placeholderName = match[1];
const value = substitutions[placeholderName];
if (!value) {
// eslint-disable-next-line no-console
console.error(
`i18n: Value not provided for placeholder ${placeholderName} in key '${key}'`
);
}
builder += value || '';
lastTextIndex = FIND_REPLACEMENTS.lastIndex;
match = FIND_REPLACEMENTS.exec(message);
}
if (lastTextIndex < message.length) {
builder += message.slice(lastTextIndex);
}
return builder;
},
[messages]
);
return (
<I18nContext.Provider value={getMessage}>{children}</I18nContext.Provider>
);
};
export const useI18n = (): I18nFn => React.useContext(I18nContext);