如何处理redux中的redux承诺中间件AJAX错误？

Question

在还原器上处理AJAX错误的合适位置是什么？(如果使用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。我处理这件事的方法是：

  if (action.error) {
    return state;
  }

所以整个减速机是：

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;
  }

}

以上是处理调用所能产生的所有类型错误的正确方法吗？如果没有，那么什么是正确的方法？

Answer 1

一.基本方式：

( a)定义您的行为创建者：

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)界定减速器：

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)集装箱：

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.高级方法:像nross83在这里所做的那样，自己定义中间件：Redux: Using async middlewares vs dispatching actions on success functions

懒惰的方式:使用redux-允诺中间件，因为它将FETCH_DATA扩展到FETCH_DATA_PENDING、FETCH_DATA_FULLFILLED、FETCH_DATA_REJECTED内部和外部。请查看https://github.com/pburtchaell/redux-promise-middleware/tree/master/examples上的示例

希望这能帮上忙。