Example analysis of 60s countdown for obtaining verification code in WeChat mini program

class Countdown {
constructor(options = {}) {
Object.assign(this, {
options, 
})
this.__init()
}
/**
* 初始化
*/
__init() {
this.page = getCurrentPages()[getCurrentPages().length - 1]
this.setData = this.page.setData.bind(this.page)
this.restart(this.options)
}
/**
* 默认参数
*/
setDefaults() {
return {
date: `June 7, 2087 15:03:25`, 
refresh: 1000, 
offset: 0, 
onEnd() {}, 
render(date) {}, 
}
}
/**
* 合并参数
*/
mergeOptions(options) {
const defaultOptions = this.setDefaults()
for (let i in defaultOptions) {
if (defaultOptions.hasOwnProperty(i)) {
this.options[i] = typeof options[i] !== `undefined` ? options[i] : defaultOptions[i]
if (i === `date` && typeof this.options.date !== `object`) {
this.options.date = new Date(this.options.date)
}
if (typeof this.options[i] === `function`) {
this.options[i] = this.options[i].bind(this)
}
}
}
if (typeof this.options.date !== `object`) {
this.options.date = new Date(this.options.date)
}
}
/**
* 计算日期差
*/
getDiffDate() {
let diff = (this.options.date.getTime() - Date.now() + this.options.offset) / 1000
let dateData = {
years: 0,
days: 0,
hours: 0,
min: 0,
sec: 0,
millisec: 0,
}
if (diff <= 0) {
if (this.interval) {
this.stop()
this.options.onEnd()
}
return dateData
}
if (diff >= (365.25 * 86400)) {
dateData.years = Math.floor(diff / (365.25 * 86400))
diff -= dateData.years * 365.25 * 86400
}
if (diff >= 86400) {
dateData.days = Math.floor(diff / 86400)
diff -= dateData.days * 86400
}
if (diff >= 3600) {
dateData.hours = Math.floor(diff / 3600)
diff -= dateData.hours * 3600
}
if (diff >= 60) {
dateData.min = Math.floor(diff / 60)
diff -= dateData.min * 60
}
dateData.sec = Math.round(diff)
dateData.millisec = diff % 1 * 1000
return dateData
}
/**
* 补零
*/
leadingZeros(num, length = 2) {
num = String(num)
if (num.length > length) return num
return (Array(length + 1).join(`0`) + num).substr(-length)
}
/**
* 更新组件
*/
update(newDate) {
this.options.date = typeof newDate !== `object` ? new Date(newDate) : newDate
this.render()
return this
}
/**
* 停止倒计时
*/
stop() {
if (this.interval) {
clearInterval(this.interval)
this.interval = !1
}
return this
}
/**
* 渲染组件
*/
render() {
this.options.render(this.getDiffDate())
return this
}
/**
* 启动倒计时
*/
start() {
if (this.interval) return !1
this.render()
if (this.options.refresh) {
this.interval = setInterval(() => {
this.render()
}, this.options.refresh)
}
return this
}
/**
* 更新offset
*/
updateOffset(offset) {
this.options.offset = offset
return this
}
/**
* 重启倒计时
*/
restart(options = {}) {
this.mergeOptions(options)
this.interval = !1
this.start()
return this
}
}

<view class="weui-cell__ft">
 <view class="weui-vcode-btn" bindtap="vcode">{{ c2 || &#39;获取验证码&#39; }}</view>
</view>

import $wuxCountDown from 'countdown/countdown'
export {
 $wuxCountDown, 
}
import { $wuxCountDown } from '../../components/wux'
 vcode: function () {
 if (this.c2 && this.c2.interval) return !1
 this.c2 = new $wuxCountDown({
 date: +(new Date) + 60000,
 onEnd() {
 this.setData({
  c2: '重新获取验证码',
 })
 },
 render(date) {
 const sec = this.leadingZeros(date.sec, 2) + ' 秒后重发 '
 date.sec !== 0 && this.setData({
  c2: sec,
 })
 },
 })
 }