javascript-工具函数

/**
 * 解析日期
 * @param {(Object|string|number)} time
 * @param {string} cFormat
 * @returns {string | null}
 */
export function parseTime(time, cFormat) {
  if (arguments.length === 0 || !time) {
    return null
  }
  const format = cFormat || '{y}-{m}-{d} {h}:{i}:{s}'
  let date
  if (typeof time === 'object') {
    date = time
  } else {
    if ((typeof time === 'string')) {
      if ((/^[0-9]+$/.test(time))) {
        // support "1548221490638"
        time = parseInt(time)
      } else {
        // support safari
        // https://stackoverflow.com/questions/4310953/invalid-date-in-safari
        time = time.replace(new RegExp(/-/gm), '/')
      }
    }

    if ((typeof time === 'number') && (time.toString().length === 10)) {
      time = time * 1000
    }
    date = new Date(time)
  }
  const formatObj = {
    y: date.getFullYear(),
    m: date.getMonth() + 1,
    d: date.getDate(),
    h: date.getHours(),
    i: date.getMinutes(),
    s: date.getSeconds(),
    a: date.getDay()
  }
  const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {
    const value = formatObj[key]
    // Note: getDay() returns 0 on Sunday
    if (key === 'a') { return ['日', '一', '二', '三', '四', '五', '六'][value ] }
    return value.toString().padStart(2, '0')
  })
  return time_str
}

/**
 * 三位分节发
 * @param number
 * @returns {string}
 */
export function formatNumber(number) {
  const numbers = number.toString().split('').reverse()
  const segs = []

  while (numbers.length) segs.push(numbers.splice(0, 3).join(''))

  return segs.join(',').split('').reverse().join('')
}

/**
 * vue自定义指令
 * 数字翻牌器
 * 同一个组件多出使用该指令，会出现重复执行问题。同一个组件中该指令各处的响应式数据同时赋值已解决该问题
 */
export const countTo = {
  componentUpdated: function(el, binding) {
    let i = 1
    const timer = setInterval(() => {
      el.innerHTML = `${Math.round(binding.value / 20 * i)}`
      if (i === 20) {
        clearInterval(timer)
      }
      i++
    }, 30)
  }
}