react-组件props校验

使用场景

组件props的校验写法，增加组件的健壮性

props是由外部传入的，其实无法保证组件使用者传入了什么格式的数据，如果传入的数据格式不对，就有可能会导致组件内部错误，有一个点很关键 - 组件的使用者可能报错了也不知道为什么

1. 安装属性校验包：yarn add prop-types
2. 导入prop-types 包
3. 使用 组件名.propTypes = {} 给组件添加校验规则

import PropTypes from 'prop-types'

const Son = ({ List }) => {

  return <>
    {List.map((item, index) => <p key={index}>{item}</p>)}
  </>
}

Son.propTypes = {
  List: PropTypes.array
}

function App () {
  return <div className="App">
    <Son List={[1, 2, 3, 4, 5]} />
  </div>
}

export default App

规则说明

---

1. 常见类型：array、bool、func、number、object、string
2. React元素类型：element
3. 必填项：isRequired
4. 特定的结构对象：shape({})

// 常见类型
optionalFunc: PropTypes.func,
// 必填 只需要在类型后面串联一个isRequired
requiredFunc: PropTypes.func.isRequired,
// 特定结构的对象
optionalObjectWithShape: PropTypes.shape({
	color: PropTypes.string,
	fontSize: PropTypes.number
})

import PropTypes from 'prop-types'
const Son = () => {

  return <>
  </>
}
Son.propTypes = {
  List: PropTypes.array.isRequired
}

function App () {
  return <div className="App">
    <Son />
  </div>
}
export default App


react-jsx-dev-runtime.development.js:87 Warning: Failed prop type: The prop `List` is marked as required in `Son`, but its value is `undefined`.
    at Son
    at App

官方链接

import PropTypes from 'prop-types';

MyComponent.propTypes = {
  // You can declare that a prop is a specific JS type. By default, these
  // are all optional.
  optionalArray: PropTypes.array,
  optionalBool: PropTypes.bool,
  optionalFunc: PropTypes.func,
  optionalNumber: PropTypes.number,
  optionalObject: PropTypes.object,
  optionalString: PropTypes.string,
  optionalSymbol: PropTypes.symbol,

  // Anything that can be rendered: numbers, strings, elements or an array
  // (or fragment) containing these types.
  optionalNode: PropTypes.node,

  // A React element.
  optionalElement: PropTypes.element,

  // A React element type (ie. MyComponent).
  optionalElementType: PropTypes.elementType,

  // You can also declare that a prop is an instance of a class. This uses
  // JS's instanceof operator.
  optionalMessage: PropTypes.instanceOf(Message),

  // You can ensure that your prop is limited to specific values by treating
  // it as an enum.
  optionalEnum: PropTypes.oneOf(['News', 'Photos']),

  // An object that could be one of many types
  optionalUnion: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.number,
    PropTypes.instanceOf(Message)
  ]),

  // An array of a certain type
  optionalArrayOf: PropTypes.arrayOf(PropTypes.number),

  // An object with property values of a certain type
  optionalObjectOf: PropTypes.objectOf(PropTypes.number),

  // An object taking on a particular shape
  optionalObjectWithShape: PropTypes.shape({
    color: PropTypes.string,
    fontSize: PropTypes.number
  }),

  // An object with warnings on extra properties
  optionalObjectWithStrictShape: PropTypes.exact({
    name: PropTypes.string,
    quantity: PropTypes.number
  }),   

  // You can chain any of the above with `isRequired` to make sure a warning
  // is shown if the prop isn't provided.
  requiredFunc: PropTypes.func.isRequired,

  // A required value of any data type
  requiredAny: PropTypes.any.isRequired,

  // You can also specify a custom validator. It should return an Error
  // object if the validation fails. Don't `console.warn` or throw, as this
  // won't work inside `oneOfType`.
  customProp: function(props, propName, componentName) {
    if (!/matchme/.test(props[propName])) {
      return new Error(
        'Invalid prop `' + propName + '` supplied to' +
        ' `' + componentName + '`. Validation failed.'
      );
    }
  },

  // You can also supply a custom validator to `arrayOf` and `objectOf`.
  // It should return an Error object if the validation fails. The validator
  // will be called for each key in the array or object. The first two
  // arguments of the validator are the array or object itself, and the
  // current item's key.
  customArrayProp: PropTypes.arrayOf(function(propValue, key, componentName, location, propFullName) {
    if (!/matchme/.test(propValue[key])) {
      return new Error(
        'Invalid prop `' + propFullName + '` supplied to' +
        ' `' + componentName + '`. Validation failed.'
      );
    }
  })
};

校验-默认值

defaultProps 可以给组件的props设置默认值，在未传入props的时候生效

函数式组件

const Son = ({ pageSize }) => {
  return <>
    {pageSize}
  </>
}

Son.defaultProps = {
  pageSize: 10
}


function App () {
  return <div className="App">
    <Son />
  </div>
}


// function App () {
//   return <div className="App">
//     <Son pageSize={20} />
//   </div>
// }

export default App

官方推荐

const Son = ({ pageSize = 10 }) => {
  return <>
    {pageSize}
  </>
}


function App () {
  return <div className="App">
    <Son />
  </div>
}


// function App () {
//   return <div className="App">
//     <Son pageSize={20} />
//   </div>
// }

export default App

类组件

import React from 'react'
class Son extends React.Component {
  render () {
    return (
      <div>{this.props.pageSize}</div>
    )
  }
}
Son.defaultProps = {
  pageSize: 10
}
function App () {
  return <div className="App">
    <Son />
  </div>
}
export default App

使用类静态属性声明默认值，static defaultProps = {}

import React from 'react'
class Son extends React.Component {
  static defaultProps = {
    pageSize: 10
  }
  render () {
    return (
      <div>{this.props.pageSize}</div>
    )
  }
}

function App () {
  return <div className="App">
    <Son pageSize={20} />
  </div>
}
export default App