未调用 react redux 嵌套调度

Question

我正在使用带有 react native 的 redux，我需要重新使用我的操作

const fetchPosts = () => {

  return (dispatch) => {

    Api.get('/posts')
       .then(response => dispatch({type: FETCH_POSTS_SUCCESS, payload: response}))
       .catch(err => dispatch({type: FETCH_POSTS_FAIL, payload: err}))
  }
}

我想在登录后总是获取帖子

const login = ({username, password}) => {

  return (dispatch) => {

    Api.post('/auth', {username, password})
       .then(response => dispatch({type: LOGIN_SUCCESS, payload: response})
       .then(() => fetchPosts())
       .catch(err => dispatch({type: LOGIN_FAIL, payload: err}))
  }
}

问题是获取帖子调度永远不会发生，因为。

有什么建议吗？

Answer 1

你应该dispatch(fetchPosts())，你可以在同一个then回调中直接在dispatch({type: LOGIN_SUCCESS, payload: response}之后调用它，或者保留在第二个then回调中，它们都可以：

const login = ({username, password}) => {

  return (dispatch) => {

    Api.post('/auth', {username, password})
      .then(response => {
        dispatch({type: LOGIN_SUCCESS, payload: response}
        dispatch(fetchPosts())
      })
      .catch(err => dispatch({type: LOGIN_FAIL, payload: err}))
  }
}

Answer 2

代码不起作用的主要原因是 fetchPosts 没有返回承诺。试试下面的代码：

const fetchPosts = (dispatch) => {
    return Api.get('/posts')
       .then(response => dispatch({type: FETCH_POSTS_SUCCESS, payload: response}))
       .catch(err => dispatch({type: FETCH_POSTS_FAIL, payload: err}))
}

const login = ({username, password}) => {
  return (dispatch) => {
    Api.post('/auth', {username, password})
       .then(response => dispatch({type: LOGIN_SUCCESS, payload: response})
       .then(() => fetchPosts(dispatch))
       .catch(err => dispatch({type: LOGIN_FAIL, payload: err}))
  }
}