This article mainly introduces the use and configuration of React mongodb, which has certain reference value. Now I share it with everyone. Friends in need can refer to it
React environment construction (step by step)
Basic configuration of React
(React is a JAVASCRIPT library used to build user interfaces. React is mainly used to build UI. Many people think that React
is the V (view) in MVC. )
npm install -g create-react-app Global installation
create-react-app react_mongodb (This is my project name)
The following is my installation process
4. Enter the project npm start and see the following effect to indicate that the project has been The construction was successful
5. Let me analyze the directory structure for everyone to understand
6 .Open webpack configuration (npm run eject) or configure it yourself
After running the command, you will see the following directory
Basic use of redux
-
Lead everyone to get started with redux
1> First download npm i redux --save
2> After we have seen the redux example, now we split the code
3> Introduction to synchronous and asynchronous (react requires the redux-thunk plug-in to handle asynchronous processing)
* redux.js
const ADD = '嘻嘻'
const REMOVE = '呵呵'
// reducer
export function counter(state = 0, action) {
switch (action.type) {
case ADD:
return state + 1;
case REMOVE:
return state - 1;
default:
return 10;
}
}
// action creator
export function addgun() {
return { type: ADD }
}
export function removegun() {
return { type: REMOVE }
}
// 异步函数操作
export function addgunAsync() {
return dispatch => { // dispatch参数
setTimeout(() => {
dispatch(addgun())
}, 2000)
}
}
* 在index.js中引入
import React from 'react';
import ReactDOM from 'react-dom';
import { createStore, applyMiddleware } from 'redux'; // applyMiddleware 处理中间键
import thunk from 'redux-thunk'; // 中间键
import registerServiceWorker from './registerServiceWorker';
import App from './App';
import { counter, addgun, removegun, addgunAsync } from './redux';
// 创建一个store counter执行reducer方法
const store = createStore(counter, applyMiddleware(thunk))
// const store = createStore(counter)
function render() {
ReactDOM.render(<app></app>, document.getElementById('root'));
}
render()
// 更新后重新渲染
store.subscribe(render)
// ReactDOM.render(<app></app>, document.getElementById('root'));
registerServiceWorker();
* App.js 组件
import React, { Component } from 'react';
export default class App extends Component {
render() {
const store = this.props.store
const num = store.getState()
// 由父组件中传入
const addgun = this.props.addgun
const removegun = this.props.removegun
const addgunAsync = this.props.addgunAsync
return (
<p>
</p><h1>
hello
<br>
{num}
</h1>
<button> store.dispatch(addgun())}>加一</button>
<button> store.dispatch(removegun())}>减一</button>
<button> store.dispatch(addgunAsync())}>异步添加</button>
)
}
}
* 这里你可以打开浏览器查看效果Copy after login
-
react-redux is installed using npm i react-redux -S (abbreviation of --save)
Provider 组件应用在最外层, 传入store,只调用一次
connect 负责从外部获取组件需要的参数
connect 可以用装饰器的方式来写
& 下面是修改过的代码: 依然使用redux.js
修改了**App.js index.js**
index.js
import React from 'react';
import ReactDOM from 'react-dom';
import { createStore, applyMiddleware, compose } from 'redux'; // applyMiddleware 处理中间键
import thunk from 'redux-thunk'; // 中间键
import { Provider } from 'react-redux';
import registerServiceWorker from './registerServiceWorker';
import App from './App';
import { counter } from './redux';
// 创建一个store counter执行reducer方法
const store = createStore(counter, compose(
applyMiddleware(thunk),
window.devToolsExtension ? window.devToolsExtension() : f => f
))
ReactDOM.render(
<provider>
<app></app>
</provider>,
document.getElementById('root'));
registerServiceWorker();Copy after login
App.js 组件
import React, { Component } from 'react';
// 连接使用
import { connect } from 'react-redux';
import { addgun, removegun, addgunAsync } from './redux/index.redux';
class App extends Component {
render() {
return (
<p>
</p><h1>
hello
<br>
{this.props.num}
</h1>
<button>加一</button>
<button>减一</button>
<button>异步添加</button>
)
}
}
const mapStatetoProps = (state)=> {
return { num: state }
}
const actionCreators = { addgun, removegun, addgunAsync }
// 装饰器的使用 connect 链接过后可以用 this.props 获取
App = connect(mapStatetoProps, actionCreators)(App)
export default App;
** 这里是不是感觉比store.subscribe方便一点Copy after login
(调试react 推荐谷歌插件 Redux DevTools) 在谷歌商店下载需要翻墙
Copy after login
react-router4
##
*注意点*： 下载router包 npm i react-router-dom --save
react-router-dom 也有2个路由参数
HashRouter（带#路由）
BrowserRouter （不带#号） 如果使用这种路由 和Vue一样需要后台配置
下面提供代码 供朋友参考：
import React from 'react';
import ReactDOM from 'react-dom';
import registerServiceWorker from './registerServiceWorker';
import { createStore, applyMiddleware, compose } from 'redux'; // applyMiddleware 处理中间键
import thunk from 'redux-thunk'; // 中间键
import { Provider } from 'react-redux';
import { BrowserRouter, Route, Link, Redirect, Switch } from 'react-router-dom';
import App from './App';
import { counter } from './redux/index.redux';
// 创建一个store counter执行reducer方法
const store = createStore(counter, compose(
applyMiddleware(thunk),
window.devToolsExtension ? window.devToolsExtension() : f => f
))
class about extends React.Component {
render () {
return (
<h1>关于详情: {this.props.match.params.id}</h1>
)
}
}
function home() {
return <h1>我的详情</h1>
}
ReactDOM.render(
(
<provider>
<browserrouter>
<p>
</p>
<ul>
<li>
<link>嘻嘻嘻
</li>
<li>
<link>关于
</li>
<li>
<link>我的
</li>
</ul>
<switch>
{/* {Switch} 默认只会匹配第一个 */}
<route></route>
<route></route>
{/* match.params.id 取值 */}
<route></route>
</switch>
</browserrouter>
{/* <app></app> */}
</provider>
),
document.getElementById('root'));
registerServiceWorker();
*Copy after login
react-router4 jumps inconsistently with other versions
如果使用一下跳转方式 会包错 push
this.props.history.push('/about')
在4.x 中提供了一个高阶组件 withRouter
import { withRouter } from "react-router-dom";
eg: 以下事例
import React, { Component } from 'react';
import { withRouter } from "react-router-dom";
class Info extends Component {
handleClick() {
this.props.history.push('/about')
}
render() {
return (
<button> this.handleClick()}>加一</button>
)
}
}
export default withRouter(Info);
后续更新全部！！！！Copy after login
The above is the entire content of this article. I hope it will be helpful to everyone's study. For more related content, please pay attention to the PHP Chinese website!
Related recommendations:
How to use NodeJS Lighthouse Gulp to build an automated website performance testing tool
The above is the detailed content of Usage and configuration of React+mongodb. For more information, please follow other related articles on the PHP Chinese website!
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
