Question

在减速机上处理AJAX错误的适当位置是什么？（如果您使用Redux加上redux-promise中间件）。

至少应该有3种类型的错误：网络错误/超时，未找到数据或500内部服务器错误。我尝试处理它的方式是：

  if (action.error) {
    return state;
  }

所以整个减速器是：

export default function(state = [], action) {

  if (action.error) {
    return state;
  }

  switch (action.type) {
    case FETCH_WEATHER:
      return [action.payload.data].concat(state);
    default:
      return state;
  }

}

以上是处理AJAX调用可能具有的所有错误类型的正确方法吗？如果没有，那么什么是正确的方式？

Answer 1

予。基本方式：

a）定义您的行动创作者：

import axios from 'axios';

//Post list
export const FETCH_DATA = 'FETCH_DATA';
export const FETCH_DATA_SUCCESS = 'FETCH_DATA_SUCCESS';
export const FETCH_DATA_FAILURE = 'FETCH_DATA_FAILURE';

const ROOT_URL = 'foo/bar';
export function fetchPosts() {
  const request = axios({
    method: 'get',
    url: `${ROOT_URL}/data`,
    headers: []
  });

  return {
    type: FETCH_DATA,
    payload: request
  };
}

export function fetchDataSuccess(data) {
  return {
    type: FETCH_DATA_SUCCESS,
    payload: data
  };
}

export function fetchDataFailure(error) {
  return {
    type: FETCH_DATA_FAILURE,
    payload: error
  };
}

b）定义减速器：

import { FETCH_DATA, FETCH_DATA_SUCCESS, FETCH_DATA_FAILURE } from 'pathToActionTypes';
export default function(state = INITIAL_STATE, action) {
  let error;
  switch(action.type) {

  case FETCH_DATA: // start fetching and set fetching = true
    return { ...state, dataObj: {data:[], error: null, fetching: true} }; 
  case FETCH_DATA_SUCCESS:// return data and set fetching = false
    return { ...state, dataObj: {data: action.payload, error:null, fetching: false} };
  case FETCH_DATA_FAILURE:// return error and set fetching = false
    error = action.payload || {message: action.payload.message}; // message could be provided if network/server down errors
    return { ...state, dataOjb: {data: [], error: error, fetching: false} };
  default:
    return state;
  }
}

c）容器：

import { connect } from 'react-redux'
import { fetchData, fetchDataSuccess, fetchDataFailure } from 'pathToActionCreators';    
import FooBarComponent from '../components/foo_bar_component';


const mapStateToProps = (state) => {
  return { 
    fooBar: state.dataObj.data
  };
}

const mapDispatchToProps = (dispatch) => {
  return {
    fetchData: () => {
      dispatch(fetchData()).then((response) => {
            !response.error ? 
            dispatch(fetchDataSuccess(response.payload.data)) : 
            dispatch(fetchDataFailure(response.payload.data));
          });
    }
  }
}

export default connect(mapStateToProps, mapDispatchToProps)(FooBarComponent);

II。高级方式：自己定义你的中间件nross83在这里做了： Redux: Using async middlewares vs dispatching actions on success functions

III。懒惰的方式：使用redux-promise-middleware，因为它在内部和外部将FETCH_DATA扩展到FETCH_DATA_PENDING，FETCH_DATA_FULLFILLED，FETCH_DATA_REJECTED。请查看https://github.com/pburtchaell/redux-promise-middleware/tree/master/examples

上的示例

希望这可能会有所帮助。

如何在reducer中处理Redux的redux-promise中间件AJAX错误？

1 个答案: