action.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 };
constraint.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';
reducer.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
event.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
一切都很好,但我希望在成功提交表单后,它需要重定向到某个页面。没有react redux很简单,我们可以在提交表单后简单地重定向,但我正在努力学习redux,对redux了解不多。我试图在reduce中使用success=true,它第一次起作用,但由于redux保持状态,当我试图打开链接时,它会自动重定向到主页,因为success=true由react redux保持。如有任何帮助,将不胜感激
首先:确保每次操作重置success
:
function eventAddReducer(state = {}, action) {
switch(action.type) {
case EVENT_ADD_REQUEST:
return {
loading: true,
success: null // <-- Look at this
};
/** ... */
};
};
第二:将success
存储变量连接到组件,并在componentDidupdate
事件中检查它,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);
使用挂钩
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);
我现在遇到了同样的问题,我用两种方法解决了它
- 第一步:在
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
我们只能在返回之后而不是之前从存储还原器访问成功值,所以你可以根据你的条件每次重新渲染和重定向都访问值
现在在react-router-dom v6
中,您可以使用useNavigate()
并对以下行进行更改
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
- 第二个:您可以在
action.js
中通过发送navigation作为调度操作的参数来设置条件,并在调度成功后编写条件,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
和在action.js
文件
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 };
我知道这不是最理想的解决方案,但创建一个可以重置成功并将其发送到useEffect内部的操作怎么样?
类似这样的东西:
还原剂
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 }
并在您的event.js文件中调用一个将调度RESET的操作。确保你把它放在一个有用的效果里面。
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>
</>
)
)}
这样做会有所帮助。