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使用 Redux 时，动作必须是普通对象

本文介绍了使用 Redux 时，动作必须是普通对象的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我收到类似的错误动作必须是普通对象.使用自定义中间件进行异步操作在使用 react redux 时.我正在开发具有登录功能的应用程序.这是我的代码.

组件

import React, { Component } from 'react';从 'prop-types' 导入 PropTypes；从'react-redux'导入{connect}；从redux"导入{bindActionCreators}；从material-ui/Paper"导入纸张；从 'material-ui/TextField' 导入 TextField；从'material-ui/RaisedButton'导入RaisedButton；import * as AuthActions from '../../actions/AuthAction';从material-ui/styles/colors"导入 {blueGrey50,lightBlue500}；常量样式 = {高度:350，宽度:370，左边距:80，边距:380，边距顶部:80，底边距:50，文本对齐:'居中'，显示:'内联块'，backgroundColor: blueGrey50,填充顶部:20，};常量样式 1 = {颜色:浅蓝色500};const style2 = {保证金:12，};类登录扩展组件{构造函数(道具){超级(道具)；this.state = {电子邮件: ''，密码: ''};}唱歌=()=>{console.log('登录');this.props.SigninActions.signIn({email:this.state.email,password:this.state.password});this.setState({email: '',password: '',loading:true});console.log('完成发送到动作');}使成为() {返回 (<div style={{backgroundImage: "url(" + "https://addmeskype.files.wordpress.com/2015/09/d62cb-teenagers-offlinle-online.jpg" + ")",宽度:1301，高度:654}}><Paper style={style} zDepth={2}><h1 style={style1}><center>登录</center></h1><TextField hintText="Email";floatLabelText="电子邮件"onChange={e=>{this.setState({email:e.target.value})}}/><TextFieldhintText=密码"floatLabelText="密码";类型=密码"onChange={p=>{this.setState({password:p.target.value})}}/><br/><br/><RaisedButton label="Sign In";primary={true} style={style2} onTouchTap={this.singin}/></纸>{(this.props.isError)?<span>电子邮件或密码组合错误！</span>:<div>没有错误</div>}

);}}登录.PropTypes = {isError: PropTypes.bool,登录操作:PropTypes.object}const mapStateToProps = (state,ownProps) =>{返回 {isError: state.isError}}const mapDispatchToProps = (调度) =>{返回 {SigninActions:bindActionCreators(AuthActions,dispatch)};}导出默认连接(mapStateToProps，mapDispatchToProps)(登录)；

操作

从'axios'导入axios；从'jwt-decode'导入jwtDecode；从 '../constants/user' 导入 { SIGN_UP_REQUEST, SIGN_IN_REQUEST, GET_USER_DETAILS, UPDATE_USER_DETAILS };export const getUserDetails=(email)=>{axios.get('http://localhost:3030/user',电子邮件).then((数据)=>{控制台日志(数据)；返回 ({类型:GET_USER_DETAILS，用户:data.data});}).catch((错误)=>{console.log('err', 错误);});}export const updateUserDetails=(user)=>{axios.put('http://localhost:3030/user',用户).then((数据)=>{控制台日志(数据)；返回 ({类型:UPDATE_USER_DETAILS，用户:data.data});}).catch((错误)=>{console.log('err', 错误);});}

减速器

import { SIGN_UP_REQUEST, SIGN_IN_REQUEST} from '../constants/user';常量初始状态 = {加载:假，isError: 假};导出默认函数用户(状态 = 初始状态，动作){开关(动作.类型){情况 SIGN_UP_REQUEST:return Object.assign({},state,{isError:action.data.isError});情况 SIGN_IN_REQUEST:return Object.assign({},state,{isError:action.data.isError});默认:返回状态；}}

Rootreducer

import { combineReducers } from 'redux';从'./ChatReducer'导入ChatReducer；从 './UserReducer' 导入 UserReducer；导出默认的 combineReducers({聊天:ChatReducer，用户:UserReducer})

商店

import { createStore, applyMiddleware } from 'redux';从redux-thunk"导入 thunk；从'../reducers/RootReducer'导入RootReducer；导出默认值() =>{返回 createStore(RootReducer,window.__REDUX_DEVTOOLS_EXTENSION__ &&window.__REDUX_DEVTOOLS_EXTENSION__());}

浏览器将错误显示为

如何克服这个问题?.我对 redux 很陌生.

解决方案

Vanilla redux 只处理普通的对象操作，比如

{ type: SOME_ACTION, ...parameters }

同步返回.

如果你想返回 Promises，你需要考虑使用像 redux-thunk 这样的中间件或者，实际上，除了来自动作创建者的普通对象之外的任何东西(或者，在这种情况下，处理异步动作).

参见:如何调度带有超时的 Redux 操作?

问题有两方面:

第一: 

export const getUserDetails = (email) =>{axios.put('http://localhost:3030/user', user) .then((data) => {返回 {类型:UPDATE_USER_DETAILS，用户:data.data};});});

您在承诺 (axios.put) 内返回一个操作，但您没有返回承诺 - javascript 无法按照您的预期工作.return，在这种情况下，仅限于最近的父作用域；在这种情况下，promise 主体.根据您目前的情况，getUserDetails 动作创建者的返回类型是 undefined.

//这在技术上仍然是*错误的*，见下文export const getUserDetails = (email) =>{//注意下一行的返回return axios.put('http://localhost:3030/user', user) .then((data) => {返回 {类型:UPDATE_USER_DETAILS，用户:data.data};});});

返回一个 Promise 仍然没有真正解决您的问题.

第二:使用 redux-thunk 时，你将你的动作包装在一个像

这样的函数中

export const getUserDetails = (email) =>{返回(调度)=>{return axios.put('http://localhost:3030/user', user) .then((data) => {//这是触发动作的地方派遣({类型:UPDATE_USER_DETAILS，用户:data.data});//如果要访问这个API调用的结果，可以在这里返回//返回的 promise 将解析为您在此处返回的任何内容返回数据；});}});

当您绑定动作创建者时，它会在保留方法签名的同时解开"创建者 - 您可以像平常一样使用它

this.props.getUserDetails("[email protected]").then((data) => {//可选的已解决承诺})

Im getting an error likeActions must be plain objects. Use custom middleware for async actionswhile using react redux. Im developing an application with a login functionality. Here is my code.

component

import React, { Component } from 'react';
import PropTypes from 'prop-types';
import {connect} from 'react-redux';
import {bindActionCreators} from 'redux';
import Paper from 'material-ui/Paper';
import TextField from 'material-ui/TextField';
import RaisedButton from 'material-ui/RaisedButton';
import * as AuthActions from '../../actions/AuthAction';
import {blueGrey50,lightBlue500} from 'material-ui/styles/colors';

const style = {
  height: 350,
  width: 370,
  marginLeft: 80,
  marginRight: 380,
  marginTop: 80,
  marginBottom: 50,
  textAlign: 'center',
  display: 'inline-block',
  backgroundColor: blueGrey50,
  paddingTop: 20,
};

const style1 = {
  color: lightBlue500
};

const style2 = {
  margin: 12,
};

class Login extends Component {
    constructor(props) {
      super(props);
      this.state = {
        email: '',
        password: ''
      };

    }

    singin=()=>{
      console.log('signing in');
      this.props.SigninActions.signIn({email:this.state.email,password:this.state.password});
      this.setState({email: '',password: '',loading:true});
      console.log('done sending to actions');
    }

    render() {
      return (
        <div style={{backgroundImage: "url(" + "https://addmeskype.files.wordpress.com/2015/09/d62cb-teenagers-offlinle-online.jpg" + ")",
                     width:1301, height:654}}>
          <Paper style={style} zDepth={2}>
            <h1 style={style1}><center>Sign In</center></h1>
            <TextField hintText="Email" floatingLabelText="Email" onChange={e=>{this.setState({email:e.target.value})}}/>
            <TextField hintText="Password" floatingLabelText="Password" type="password" onChange={p=>{this.setState({password:p.target.value})}}/>
            <br/><br/>
            <RaisedButton label="Sign In" primary={true} style={style2} onTouchTap={this.singin}/>
          </Paper>
          {
            (this.props.isError)? <span>Email or Password combination is wrong!</span> : <div>No errors</div>
          }
        </div>
      );
    }
}

Login.PropTypes = {
  isError: PropTypes.bool,
  SigninActions: PropTypes.object
}

const mapStateToProps = (state,ownProps) => {
  return {
    isError: state.isError
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    SigninActions:bindActionCreators(AuthActions,dispatch)
  };
}

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

Actions

import axios from 'axios';
import jwtDecode from 'jwt-decode';
import { SIGN_UP_REQUEST, SIGN_IN_REQUEST, GET_USER_DETAILS, UPDATE_USER_DETAILS } from '../constants/user';

export const getUserDetails=(email)=>{

    axios.get('http://localhost:3030/user',
        email
      )
      .then((data)=>{
        console.log(data);
        return ({
            type: GET_USER_DETAILS,
            user:data.data
        });
      })
      .catch((error)=>{
        console.log('err', error);
      });
}


export const updateUserDetails=(user)=>{

    axios.put('http://localhost:3030/user',
        user
      )
      .then((data)=>{
        console.log(data);
        return ({
            type: UPDATE_USER_DETAILS,
            user:data.data
        });
      })
      .catch((error)=>{
        console.log('err', error);
      });
}

Reducer

import { SIGN_UP_REQUEST, SIGN_IN_REQUEST} from '../constants/user';

const initialState = {
  loading: false,
  isError: false
};


export default function User(state = initialState, action) {
  switch (action.type) {
    case SIGN_UP_REQUEST:
      return Object.assign({},state,{isError:action.data.isError});

    case SIGN_IN_REQUEST:
      return Object.assign({},state,{isError:action.data.isError});

    default:
      return state;
  }
}

Rootreducer

import { combineReducers } from 'redux';
import ChatReducer from './ChatReducer';
import UserReducer from './UserReducer';

export default combineReducers({
  chat: ChatReducer,
  user: UserReducer
})

Store

import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import RootReducer from '../reducers/RootReducer';


export default() => {
    return createStore(RootReducer,
  window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__());
}

The browser displays the error as

How to overcome this issue?. im quite new to redux.

解决方案

Vanilla redux only handles plain object actions such as

{ type: SOME_ACTION, ...parameters }

returned synchronously.

You need to look into using middleware like redux-thunk if you want to return Promises or, really, anything other than a plain object from your action creators (or, in this case, handle asynchronous actions).

see this: How to dispatch a Redux action with a timeout?

edit:

The problem is kind of two fold:

first: 

export const getUserDetails = (email) => {
    axios.put('http://localhost:3030/user', user) .then((data) => {
        return {
            type: UPDATE_USER_DETAILS,
            user:data.data
        };
    });
});

you're returning an action inside the promise (axios.put) but you're not returning the promise - javascript doesn't work how you're intending it to work. return, in this case, is limited to the nearest parent scope; in this case the promise body. Just given what you have currently, the return type of the getUserDetails action creator is undefined.

// this is still technically *wrong*, see below
export const getUserDetails = (email) => {
    // notice the return on the next line
    return axios.put('http://localhost:3030/user', user) .then((data) => {
        return {
            type: UPDATE_USER_DETAILS,
            user:data.data
        };
    });
});

returns a Promise<Action> which still doesn't really solve your problem.

second:When working with redux-thunk, you wrap your action in a function like

export const getUserDetails = (email) => {
    return (dispatch) => {
        return axios.put('http://localhost:3030/user', user) .then((data) => {
            // this is where the action is fired
            dispatch({
                type: UPDATE_USER_DETAILS,
                user:data.data
            });

            // if you want to access the result of this API call, you can return here
            // the returned promise will resolve to whatever you return here

            return data;
        });
    }
});

when you bind the action creator, it will "unwrap" the creator while keeping the method signature - you use it like you would normally

this.props.getUserDetails("[email protected]").then((data) => {
    // optional resolved promise
})

这篇关于使用 Redux 时，动作必须是普通对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

09-03 17:38
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