48 lines
1.7 KiB
TypeScript
48 lines
1.7 KiB
TypeScript
/*
|
|
Copyright 2021 The Matrix.org Foundation C.I.C.
|
|
|
|
Licensed 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 CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
import { useCallback, useEffect, useState } from "react";
|
|
import { Room } from "matrix-js-sdk/src/models/room";
|
|
import { RoomState, RoomStateEvent } from "matrix-js-sdk/src/models/room-state";
|
|
|
|
import { useTypedEventEmitter } from "./useEventEmitter";
|
|
|
|
type Mapper<T> = (roomState: RoomState) => T;
|
|
const defaultMapper: Mapper<RoomState> = (roomState: RoomState) => roomState;
|
|
|
|
// Hook to simplify watching Matrix Room state
|
|
// eslint-disable-next-line @typescript-eslint/no-unnecessary-type-constraint
|
|
export const useRoomState = <T extends any = RoomState>(
|
|
room?: Room,
|
|
mapper: Mapper<T> = defaultMapper as Mapper<T>,
|
|
): T => {
|
|
const [value, setValue] = useState<T>(room ? mapper(room.currentState) : (undefined as T));
|
|
|
|
const update = useCallback(() => {
|
|
if (!room) return;
|
|
setValue(mapper(room.currentState));
|
|
}, [room, mapper]);
|
|
|
|
useTypedEventEmitter(room?.currentState, RoomStateEvent.Update, update);
|
|
useEffect(() => {
|
|
update();
|
|
return () => {
|
|
setValue(room ? mapper(room.currentState) : (undefined as T));
|
|
};
|
|
}, [room, mapper, update]);
|
|
return value;
|
|
};
|