如何使用runSaga启动Redux Saga Watcher [英] How to start a redux saga watcher using runSaga

问题描述

我无法从文档中了解如何使用runSaga启动redux saga观察器.假设我在 saga.js 中具有以下内容:

I am not able to figure out from the documentation how to start a redux saga watcher using runSaga. Suppose I have the following in saga.js:

export function* fetchJokeSaga(action) {
  try {
    const response = yield call(axios.get, "...");
    yield put({ type: "UPDATE_JOKE", payload: response });
  } catch (e) {}
}

export default function* watcherSaga(action) {
  yield takeEvery("FETCH_JOKE", fetchJokeSaga);
}

以及 Component.js 中的以下内容:

const Component = () => {
  const store = useStore();
  const dispatch = useDispatch();
  const { joke } = useSelector(state => state);

  React.useEffect(() => {
    runSaga({ dispatch, getState: store.getState }, watcherSaga);
  }, []);

  return joke;
};

我无法使用 dispatch({type:'FETCH_JOKE'})触发api调用.
但是当我直接将 fetchJokeSaga 用作 runSaga({dispatch，getState:store.getState}，fetchJokeSaga); 时，它将立即进行api调用.
如何动态启动 watcherSaga ，以便以后可以分派"FETCH_JOKES"?

I'm not able to trigger the api call using dispatch({ type: 'FETCH_JOKE' }).
But when I use fetchJokeSaga directly as runSaga({ dispatch, getState: store.getState }, fetchJokeSaga);, it makes the api call immediately.
How do I dynamically start watcherSaga so that I can dispatch 'FETCH_JOKES' later?

推荐答案

azundo几乎可以解决.您需要在频道中"投放"一些操作才能启动生成器.

azundo almost had the solution. You need to 'put' some actions in the channel to get the generator started.

import {stdChannel, runSaga} from 'redux-saga';

const Component = () => {
   const store = useStore();
   const dispatch = useDispatch();
   const { joke } = useSelector(state => state);

   React.useEffect(() => {
       const channel = stdChannel();
       runSaga({ dispatch, getState: store.getState, channel}, watcherSaga);
       channel.put({ type: 'FETCH_JOKE' });
   }, []);

   return joke;
};

希望这会有所帮助.

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