Button组件
整体
- Button组件
- 主要是通过改变state状态，从而渲染时应用不同className来改变外观
- 检查是否只有2个中文字符，例如 “提交”， 检查到则会变更state中的属性，再次渲染时就会变为 “提 交”
- componentWillReceiveProps中会检查是否需要loading状态
- 渲染的dom中绑定了click，通过setTimeout方法延迟执行click动画
注意
- 学习使用classNames和omit
- React.cloneElement的使用
- 使用React.children与使用this.props.children的比较，前者更准确
- 每次render通过改变className来改变外观和动画
源码注释
import * as React from 'react';
import { findDOMNode } from 'react-dom';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import omit from 'omit.js';
import Icon from '../icon';
import Group from './button-group';
//2个中文字符
const rxTwoCNChar = /^[\u4e00-\u9fa5]{2}$/;
const isTwoCNChar = rxTwoCNChar.test.bind(rxTwoCNChar);
function isString(str: any) {
return typeof str === 'string';
}
// Insert one space between two chinese characters automatically.
function insertSpace(child: React.ReactChild, needInserted: boolean) {
// Check the child if is undefined or null.
if (child == null) {
return;
}
const SPACE = needInserted ? ' ' : '';
// strictNullChecks oops.
// child是react的组件并且组件的子元素只有2个中文字符
// 如果是<span>点击</span>,child是一个obj，里面type为"span"
if (typeof child !== 'string' && typeof child !== 'number' &&
isString(child.type) && isTwoCNChar(child.props.children)) {
// 克隆组件(element,[props],[...children])
// 也可以写成
// <child.type {...child.props}>{child.props.children.split('').join(SPACE)}</child.type>
return React.cloneElement(child, {},
child.props.children.split('').join(SPACE));
}
// child是字符串
if (typeof child === 'string') {
// child只有2个中文字符
if (isTwoCNChar(child)) {
child = child.split('').join(SPACE);
}
return <span>{child}</span>;
}
return child;
}
export type ButtonType = 'default' | 'primary' | 'ghost' | 'dashed' | 'danger';
export type ButtonShape = 'circle' | 'circle-outline';
export type ButtonSize = 'small' | 'default' | 'large';
export interface BaseButtonProps {
type?: ButtonType;
htmlType?: string;
icon?: string;
shape?: ButtonShape;
size?: ButtonSize;
loading?: boolean | { delay?: number };
prefixCls?: string;
className?: string;
ghost?: boolean;
}
export type AnchorButtonProps = BaseButtonProps & React.AnchorHTMLAttributes<HTMLAnchorElement>;
export type NativeButtonProps = BaseButtonProps & React.ButtonHTMLAttributes<HTMLButtonElement>;
export type ButtonProps = AnchorButtonProps | NativeButtonProps;
export default class Button extends React.Component<ButtonProps, any> {
static Group: typeof Group;
static __ANT_BUTTON = true;
static defaultProps = {
prefixCls: 'ant-btn',
loading: false,
ghost: false,
};
static propTypes = {
type: PropTypes.string,
shape: PropTypes.oneOf(['circle', 'circle-outline']),
size: PropTypes.oneOf(['large', 'default', 'small']),
htmlType: PropTypes.oneOf(['submit', 'button', 'reset']),
onClick: PropTypes.func,
loading: PropTypes.oneOfType([PropTypes.bool, PropTypes.object]),
className: PropTypes.string,
icon: PropTypes.string,
};
timeout: number;
delayTimeout: number;
constructor(props: ButtonProps) {
super(props);
this.state = {
loading: props.loading,
clicked: false,
hasTwoCNChar: false,
};
}
//每次创建时
componentDidMount() {
//判断子元素是否只有2个字符，并且更改state
this.fixTwoCNChar();
}
//每次prop改变
componentWillReceiveProps(nextProps: ButtonProps) {
const currentLoading = this.props.loading;
const loading = nextProps.loading;
//如果传了loading
if (currentLoading) {
//先清空之前loading的计时器
clearTimeout(this.delayTimeout);
}
//loading不为布尔值，并且存在delay属性（自定义loadidng延迟）
if (typeof loading !== 'boolean' && loading && loading.delay) {
this.delayTimeout = window.setTimeout(() => this.setState({ loading }), loading.delay);
} else {
//未自定义loading延迟
this.setState({ loading });
}
}
//每次更新render后，检查是否2中文字符
componentDidUpdate() {
this.fixTwoCNChar();
}
componentWillUnmount() {
if (this.timeout) {
clearTimeout(this.timeout);
}
if (this.delayTimeout) {
clearTimeout(this.delayTimeout);
}
}
//判断子元素是否只有2个字符，并且将判断结果给state.hasTwoCNChar
fixTwoCNChar() {
// Fix for HOC usage like <FormatMessage />
//返回已经装在的DOM（这里可能是<a>或者<button>)
const node = (findDOMNode(this) as HTMLElement);
//返回button上的值（例如：点击）
const buttonText = node.textContent || node.innerText;
//只有1个子元素，并且这个子元素是2个中文字符
if (this.isNeedInserted() && isTwoCNChar(buttonText)) {
//将state的hasTowCNChar改变为true
if (!this.state.hasTwoCNChar) {
this.setState({
hasTwoCNChar: true,
});
}
} else if (this.state.hasTwoCNChar) {
//如果不符合条件，并且hasTowCNChar为true（说明这个组件之前是2个中文字，后来update就不是了），变为false
this.setState({
hasTwoCNChar: false,
});
}
}
/**
* 每次click都通过改变state.clicked来变更class，从而改变视觉效果
*/
handleClick = (e: React.MouseEvent<HTMLButtonElement | HTMLAnchorElement>) => {
// Add click effect
this.setState({ clicked: true });
clearTimeout(this.timeout);
this.timeout = window.setTimeout(() => this.setState({ clicked: false }), 500);
const onClick = this.props.onClick;
//onClick存在，执行
if (onClick) {
(onClick as (e: React.MouseEvent<HTMLButtonElement | HTMLAnchorElement>) => void)(e);
}
}
//只有1个子元素并且没有icon
isNeedInserted() {
const { icon, children } = this.props;
return React.Children.count(children) === 1 && !icon;
}
render() {
const {
type, shape, size, className, htmlType, children, icon, prefixCls, ghost, ...others,
} = this.props;
const { loading, clicked, hasTwoCNChar } = this.state;
// large => lg
// small => sm
let sizeCls = '';
switch (size) {
case 'large':
sizeCls = 'lg';
break;
case 'small':
sizeCls = 'sm';
default:
break;
}
const ComponentProp = (others as AnchorButtonProps).href ? 'a' : 'button';
//classNames 可以将以下class变为"xx1 xx2 xx3..."的格式
//其中值为true，key成立，值为false，key不合并
const classes = classNames(prefixCls, className, {
[`${prefixCls}-${type}`]: type,
[`${prefixCls}-${shape}`]: shape,
[`${prefixCls}-${sizeCls}`]: sizeCls,
[`${prefixCls}-icon-only`]: !children && icon,
[`${prefixCls}-loading`]: loading,
[`${prefixCls}-clicked`]: clicked,
[`${prefixCls}-background-ghost`]: ghost,
[`${prefixCls}-two-chinese-chars`]: hasTwoCNChar,
});
const iconType = loading ? 'loading' : icon;
const iconNode = iconType ? <Icon type={iconType} /> : null;
//this.props.children存在时，对每一个children类型执行判断(null，react组件，字符串)并且根据判断执行添加操作
const kids = (children || children === 0)
? React.Children.map(children, child => insertSpace(child, this.isNeedInserted())) : null;
/**
* omit:从others里删除loading这个属性
* type:如果有href属性（a标签）设为undefined，如果是button则设置为传入值或者'button'
*
*/
return (
<ComponentProp
{...omit(others, ['loading'])}
type={(others as AnchorButtonProps).href ? undefined : (htmlType || 'button')}
className={classes}
onClick={this.handleClick}
>
{iconNode}{kids}
</ComponentProp>
);
}
}
