memos/web/src/labs/i18n/i18nStore.ts
2022-08-07 22:48:22 +08:00

59 lines
1.1 KiB
TypeScript

type I18nState = Readonly<{
locale: string;
}>;
type Listener = (ns: I18nState, ps?: I18nState) => void;
const createI18nStore = (preloadedState: I18nState) => {
const listeners: Listener[] = [];
let currentState = preloadedState;
const getState = () => {
return currentState;
};
const setState = (state: Partial<I18nState>) => {
const nextState = {
...currentState,
...state,
};
const prevState = currentState;
currentState = nextState;
for (const cb of listeners) {
cb(currentState, prevState);
}
};
const subscribe = (listener: Listener) => {
let isSubscribed = true;
listeners.push(listener);
const unsubscribe = () => {
if (!isSubscribed) {
return;
}
const index = listeners.indexOf(listener);
listeners.splice(index, 1);
isSubscribed = false;
};
return unsubscribe;
};
return {
getState,
setState,
subscribe,
};
};
const defaultI18nState = {
locale: "en",
};
const i18nStore = createI18nStore(defaultI18nState);
export default i18nStore;