使用 react-redux 成功提交表單后如何重定向

Question

動作.js

import axios from 'axios';
import { EVENT_ADD_FAIL, EVENT_ADD_REQUEST, EVENT_ADD_SUCCESS } from '../constraints/eventConstraint';

const addEvent = (event) => async (dispatch) => {
 dispatch({ type: EVENT_ADD_REQUEST, payload: event });
 try {
    const { data } = await axios.post(`http://localhost:4000/event`, event);
    dispatch({ type: EVENT_ADD_SUCCESS, payload:data });
 }
 catch (error) {
    dispatch({ type: EVENT_ADD_FAIL, payload:error.message });
 };
};


export { addEvent };

約束.js

export const EVENT_ADD_REQUEST = 'EVENT_ADD_REQUEST';
export const EVENT_ADD_SUCCESS = 'EVENT_ADD_SUCCESS';
export const EVENT_ADD_FAIL = 'EVENT_ADD_FAIL';

減速器.js

import {EVENT_ADD_FAIL, EVENT_ADD_REQUEST, EVENT_ADD_SUCCESS } from "../constraints/eventConstraint";

function eventAddReducer(state = {}, action) {
 switch(action.type) {
    case EVENT_ADD_REQUEST:
        return { loading: true };
    case EVENT_ADD_SUCCESS:
        return { loading: false, event: action.payload, success:true };
    case EVENT_ADD_FAIL:
        return { loading: false, error: action.payload, success:false };
    default:
        return state
 };
};

export { eventAddReducer }

store.js

import { createStore, combineReducers, applyMiddleware, compose } from 'redux';
import thunk from 'redux-thunk';
import { eventAddReducer } from './reducers/eventReducer';

const initialState = {};
const reducer = combineReducers({
  addEvent: eventAddReducer
});

const store = createStore(reducer, initialState, compose(applyMiddleware(thunk)));
export default store

事件.js

import React, { useState } from 'react';
import { useDispatch, useSelector } from 'react-redux';
import { Link, useHistory } from 'react-router-dom';
import { addEvent } from '../actions/eventAction';

const AddEvent = () => {
 const history = useHistory();
 const [event, setEvent] = useState();
 const addNewEvent = useSelector(state => state.addEvent);
 console.log(addNewEvent)
 const dispatch = useDispatch();

 const handleChange = e => {
    setEvent({ ...event,[e.target.name]:e.target.value})
 };

 const submitHandler = async (e) => {
    e.preventDefault();
    await dispatch(addEvent(event));
 };

// if(addNewEvent.success === true) {   
//     history.push('/')
// };   ===========>>>>>>>>>>> It works at first but after submission first time next time it automatically redirects to '/' because react-redux holds state

return (
    <>
        <form onSubmit = { submitHandler } >
            <div className="form-group">
                <label htmlFor="name">Name:</label>
                <input type="text" className="form-control" id="name" name="name" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="description">Description:</label>
                <input type="text" className="form-control" id="description" name="description" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="price">Price:</label>
                <input type="text" className="form-control" id="price" name="price" onChange={e => handleChange(e)} />
            </div>
            <Link to='/'> <button type="button" className="btn btn-success"> Back </button> </Link>
            <button type="submit" className="btn btn-success float-right"> Add Event </button>
        </form>
    </>
 )
};

export default AddEvent

一切正常，但我希望在成功提交表單后它需要重定向到某個頁面。 沒有 react-redux 很簡單，我們可以在提交表單后簡單地重定向，但我正在嘗試學習 redux 並且對 redux 不太了解。 我嘗試在reducer中使用success = true，它第一次工作，但是當我嘗試打開鏈接時redux保持狀態，它自動重定向到主頁，因為success = true被react-redux保持。 任何幫助將不勝感激

Answer 1

我現在遇到了同樣的問題，我通過兩種方式解決了

1. 第一個：完成您的解決方案

event.js文件：

import React, { useState } from 'react';
import { useDispatch, useSelector } from 'react-redux';
import { Link, useHistory } from 'react-router-dom';
import { addEvent } from '../actions/eventAction';

const AddEvent = () => {
 const history = useHistory();
 const [event, setEvent] = useState();
 const addNewEvent = useSelector(state => state.addEvent);
 console.log(addNewEvent)
 const dispatch = useDispatch();

 const handleChange = e => {
    setEvent({ ...event,[e.target.name]:e.target.value})
 };

 const submitHandler = async (e) => {
    e.preventDefault();
    await dispatch(addEvent(event));
 };
addNewEvent.success && history.push('/')

return (
    <>
    // after submition success only you will redirect to "/"

    {addNewEvent.success && history.push('/')}
    
        <form onSubmit = { submitHandler } >
            <div className="form-group">
                <label htmlFor="name">Name:</label>
                <input type="text" className="form-control" id="name" name="name" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="description">Description:</label>
                <input type="text" className="form-control" id="description" name="description" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="price">Price:</label>
                <input type="text" className="form-control" id="price" name="price" onChange={e => handleChange(e)} />
            </div>
            <Link to='/'> <button type="button" className="btn btn-success"> Back </button> </Link>
            <button type="submit" className="btn btn-success float-right"> Add Event </button>
        </form>
    </>
 )
};

export default AddEvent

我們只能在返回后而不是之前從 store reducer 訪問成功值，因此您可以根據您的條件在每次重新渲染和重定向時訪問值

現在在react-router-dom v6中，您可以使用useNavigate()並對以下行進行更改

import { Link, useNavigate } from "react-router-dom";
// rest of imports

const AddEvent = () => {
  const navigate = useNavigate();

//rest of code
return (
<>
{addNewEvent.success && navigate('/')}

//rest of code

</>

)
};
export default AddEvent

2. 第二個：您可以通過在調度操作上發送導航作為參數來在action.js中創建條件，並在調度成功后編寫您的條件，如下所示

event.js文件

import { Link, useNavigate } from "react-router-dom";
// rest of imports

const AddEvent = () => {
 const navigate = useNavigate();

const submitHandler = async (e) => {
   e.preventDefault();
   await dispatch(addEvent(event,navigate));
};

//rest of code
return (
<>

//rest of code

</>

)
};
export default AddEvent

在action.js文件中

import axios from 'axios';
import { EVENT_ADD_FAIL, EVENT_ADD_REQUEST, EVENT_ADD_SUCCESS } from '../constraints/eventConstraint';

const addEvent = (event,navigate) => async (dispatch) => {
 dispatch({ type: EVENT_ADD_REQUEST, payload: event });
 try {
    const { data } = await axios.post(`http://localhost:4000/event`, event);
    dispatch({ type: EVENT_ADD_SUCCESS, payload:data });
    
    //add your navigation or condition here
    navigate("/");

 }
 catch (error) {
    dispatch({ type: EVENT_ADD_FAIL, payload:error.message });
 };
};


export { addEvent };

Answer 2

首先：確保您重置每個操作的success ：

function eventAddReducer(state = {}, action) {
  switch(action.type) {
     case EVENT_ADD_REQUEST:
         return { 
           loading: true,
           success: null // <-- Look at this
          };
    /** ... */
  };
};

第二：將success存儲變量連接到您的組件，並在componentDidupdate事件中檢查它，例如：

import { connect } from 'react-redux';

class AddEvent extends React.Component {
  componentDidUpdate(prevProps) {
    const {success} = this.props;
    const {succcess: prevSuccess} = prevProps;

    if (success && success !== prevSuccess) {
      /** Redirect here */
    }
  }
  /** .... */
}

const mapStateToProps = ({ addEvent: { success } }) => ({
  success
});

export default connect(mapStateToProps)(AddEvent);

使用鈎子

const AddEvent = ({ success }) => {
  useEffect(() => {
    if (success) {
      /** Redirect here */
    }
  }, [success]); // <-- This will make sure that the effect only runs when success variable has changed
};

const mapStateToProps = ({ addEvent: { success } }) => ({
  success
});

export default connect(mapStateToProps)(AddEvent);

Answer 3

我知道這不是最理想的解決方案，但是如何創建一個重置成功的操作並將其分派到 useEffect 中呢？

像這樣的東西：

減速器

import {EVENT_ADD_FAIL, EVENT_ADD_REQUEST, EVENT_ADD_SUCCESS } from "../constraints/eventConstraint";

function eventAddReducer(state = {}, action) {
 switch(action.type) {
    case EVENT_ADD_REQUEST:
        return { loading: true };
    case EVENT_ADD_SUCCESS:
        return { loading: false, event: action.payload, success:true };
    case EVENT_ADD_FAIL:
        return { loading: false, error: action.payload, success:false };
case RESET:
      return {
         ...state, 
         loading: false, 
         success:false
      } // This will reset everything including success
    default:
        return state
 };
};

export { eventAddReducer }

並在您的 event.js 文件中調用將調度 RESET 的操作。 確保將其放在 useeffect 中。

import React, { useState } from 'react';
import { useDispatch, useSelector } from 'react-redux';
import { Link, useHistory } from 'react-router-dom';
import { addEvent } from '../actions/eventAction';

const AddEvent = () => {
 const history = useHistory();
 const [event, setEvent] = useState();
 const addNewEvent = useSelector(state => state.addEvent);
 console.log(addNewEvent)
 const dispatch = useDispatch();
React.useEffect(() =>{
myResetAction()

}, [])
 const handleChange = e => {
    setEvent({ ...event,[e.target.name]:e.target.value})
 };

const submitHandler = async (e) => {
    e.preventDefault();
    await dispatch(addEvent(event));
 };

// if(addNewEvent.success === true) {   
//     history.push('/')
// };   ===========>>>>>>>>>>> It works at first but after submission first time next time it automatically redirects to '/' because react-redux holds state

return (
    <>
        <form onSubmit = { submitHandler } >
            <div className="form-group">
                <label htmlFor="name">Name:</label>
                <input type="text" className="form-control" id="name" name="name" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="description">Description:</label>
                <input type="text" className="form-control" id="description" name="description" onChange={e => handleChange(e)} />
            </div>
            <div className="form-group">
                <label htmlFor="price">Price:</label>
                <input type="text" className="form-control" id="price" name="price" onChange={e => handleChange(e)} />
            </div>
            <Link to='/'> <button type="button" className="btn btn-success"> Back </button> </Link>
            <button type="submit" className="btn btn-success float-right"> Add Event </button>
        </form>
    </>
 )
)}

這樣做會有所幫助。