jsx

reactjs父子组件间的传值

▼魔方 西西 提交于 2019-12-03 12:03:48
父传子数据 props FatherComponent.jsx ChildComponent.jsx 父传子方法 props FatherComponent.jsx ChildComponent.jsx 带参数的方法: FatherComponent.jsx ChildComponent.jsx 父组件将自身传给子组件 props FatherComponent.jsx ChildComponent.jsx 父组件获取子组件的数据 refs FatherComponent.jsx ChildComponent.jsx 父组件获取子组件的方法 refs FatherComponent.jsx ChildComponent.jsx 带有参数的方法: FatherComponent.jsx ChildComponent.jsx 组件的defaultProps和propTypes defaultProps:用来初始化组件的props属性 ChildComponent.jsx 当父组件FatherComponent没有给子组件ChildComponent的props属性传递message参数值时,会使用default值 => message:’这里是默认信息’ 如果有传,则会覆盖掉default值。 propTypes:对组件props属性中的值进行类型约束 (is propTypes no

Converting React function component to class component issue

烂漫一生 提交于 2019-12-03 11:55:42
问题 I have the following react functional component to help support authentication required routes with react-router. const PrivateRoute = ({ component: Component, ...rest }) => ( <Route {...rest} render={props => ( isAuthenticated() ? ( <Component {...props}/> ) : ( <Redirect to={{ pathname: '/login', state: {from: props.location } }}/> ) )}/> ) I need to convert this from a functional component to a class component so I can take advantage of the componentDidMount method of React.Component.

setState for nested objects

情到浓时终转凉″ 提交于 2019-12-03 11:19:45
问题 I have a nested object as a state and I have a form in a component. I was thinking of updating the state every time the user enter something in the form and to avoid creating many functions for each input I was thinking of creating a single function using switch. Is creating a single function with switch a good idea? How can I update a single nested element of the object? I have tried with the following code but it doesn't work: class App extends Component { constructor(props) { super(props)

ReactJS JSX Syntax for If-Else

匿名 (未验证) 提交于 2019-12-03 09:52:54
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I have the following jsx code, I am trying to put some code out of the mapping function, but getting errors with the jsx syntax, I want this block displayed only if there is some data.. {this.props.someData ? <div className="container"> <h3>Heading</h3> <div className="block1"> <button>one</button> <buttontwo</button> </div> this.props.someData.map((response, index) => { return ( <div className="Block2"> <div key={index}> <span>{response.number}</span> </div> </div> </div> ); }) : ''} 回答1: Write it like this: {this.props.someData ? <div

webpack配置: 如何同时使用ES2015和JSX

自作多情 提交于 2019-12-03 08:51:03
笔记笔记,网上很多例子都是过期的啊= = 因为jsx转换器整合到babel中了,根本不需要网上所说的jsx-loader sudo npm install webpack webpack-dev-server babel -g sudo npm install react react-dom babel-loader less-loader css-loader style-loader url-loader file-loader babel-preset-es2015 babel-preset-react --save-dev module.exports = { entry: { main: './src/index.jsx', es5:'./src/es6.js' }, output: { path: 'build', filename: '[name].build.js' }, resolve: { extensions: ['','.js', '.jsx'] }, module: { loaders: [{ test: /\.jsx$/, loader: 'babel-loader', query:{ presets:['es2015','react'] } }, { test: /\.js$/, loader: 'babel-loader', query:{

How to auto indent jsx in VSCode

拈花ヽ惹草 提交于 2019-12-03 08:33:38
问题 VSCode seems doesn't auto indent HTML elements in jsx? Is there any way to fix it. Update : In Atom : When I input <div> , atom will show: After I press the return key, the result is(pay attention to the location of the cursor): While in VSCode : 回答1: Try changing the language mode to JavaScript React. Open the commands palette. Type change language mode Press Enter Type javascript react Press Enter Once that's done, you'll see the JavaScript React mode in the bottom left corner. Once you're

Is node js and JSX required for React JS

匿名 (未验证) 提交于 2019-12-03 08:28:06
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: We have chosen the react JS 0.14.8 for front end because it supports IE 8 browser but Is Node JS or JSX is necessary for React JS development or we can create components without Node JS or Jsx 回答1: Yes you can create ReactJs app without nodejs and jsx. But why you should use JSX? JSX provides a very clean way to declare your UI component. You can use your familiar html syntax to declare your user interface. JSX gets trans-piled and converted to light weight objects representing ui elements. e.g You can use following way to declare a react js

一看就懂的ReactJs入门教程-精华版

流过昼夜 提交于 2019-12-03 07:58:23
现在最热门的前端框架有AngularJS、React、Bootstrap等。自从接触了ReactJS,ReactJs的虚拟DOM(Virtual DOM)和组件化的开发深深的吸引了我,下面来跟我一起领略ReactJs的风采吧~~ 文章有点长,耐心读完,你会有很大收获哦~ 一、ReactJS简介   React 起源于 Facebook 的内部项目,因为该公司对市场上所有 JavaScript MVC 框架,都不满意,就决定自己写一套,用来架设 Instagram 的网站。做出来以后,发现这套东西很好用,就在2013年5月开源了。由于 React 的设计思想极其独特,属于革命性创新,性能出众,代码逻辑却非常简单。所以,越来越多的人开始关注和使用,认为它可能是将来 Web 开发的主流工具。 ReactJS官网地址:http://facebook.github.io/react/ Github地址:https://github.com/facebook/react 二、对ReactJS的认识及ReactJS的优点 首先,对于React,有一些认识误区,这里先总结一下: React不是一个完整的MVC框架,最多可以认为是MVC中的V(View),甚至React并不非常认可MVC开发模式; React的服务器端Render能力只能算是一个锦上添花的功能,并不是其核心出发点

After Effects / ExtendScript: Using libraries and importing .jsx files?

断了今生、忘了曾经 提交于 2019-12-03 07:36:24
问题 I am new to After Effects scripting but have much experience with JavaScript in the browser. How do I import .jsx files? Can I use js libraries such as underscore.js etc? What are some good resources for AE scripting? (Ideally infographics projects) 回答1: To include a .jsx next to your script use: #include "includeme.jsx" EDIT 2: You can also include files using the following syntax: //@include "includeme.jsx" Which (IMHO) is the better way. It wont break a linter and is more javascript-ish.

What is the best way to have variable attributes in JSX?

前提是你 提交于 2019-12-03 06:54:48
Hopefully my question is clear, I'm mainly looking for a way to dynamically attach attributes to a JSX input. <input type="text" {variableAttribute}={anotherVariable} /> Is something like this possible without overriding the way JSX compiles to JS to regular HTML? You can initialize an object with a computed property name , and then use JSX Spread Attributes to convert it to attribute: const DemoComponent = ({ variablePropName, variablePropValue }) => { const variableAttribute = { [variablePropName]: variablePropValue }; return ( <input type="text" { ...variableAttribute } /> ); }; You can't