redux-saga 如何监听多个 eventChannel

Question

我订阅了聊天室的 2 个 channel 。代码会卡在 C直到第二个 channel 收到新消息。然后卡在 A直到第一个 channel 收到新消息。

我怎样才能让 2 个 channel 分开工作。

function* ChatRoomPageEnter() {
  const chanChat = yield call($stomp.eventChannel, 'ChatRoomPage', '/topic/chat');
  const chanEcho = yield call($stomp.eventChannel, 'ChatRoomPage', '/user/queue/echo');

  while (true) { // eslint-disable-line no-constant-condition
    console.log('A');
    const messageChat = yield take(chanChat);
    console.log('B');
    yield put({ type: 'chatroom/newMessage', payload: messageChat });
    console.log('C'); // <----
    const messageEcho = yield take(chanEcho);
    console.log('D');
    yield put({ type: 'chatroom/newMessage', payload: messageEcho });
    console.log('E');
  }
}

Answer 1

为什么不创建一个观察者作为一个单独的函数并调用它两次。例如:

function * chatWatcher(chanName) {
  while(true) {
    const message = yield take(chanName);
    yield put({ type: 'chatroom/newMessage', payload: message });
  }
}

function* ChatRoomPageEnter() {
  const chanChat = yield call($stomp.eventChannel, 'ChatRoomPage', '/topic/chat');
  const chanEcho = yield call($stomp.eventChannel, 'ChatRoomPage', '/user/queue/echo');

  yield * chatWatcher(chanChat);
  yield * chatWatcher(chanEcho);
}