好用的时间插件

摘要：因为长期的项目积累自己写了一些计算时间的插件相比较我觉得比它好用补全时间月往後推幾個月格式化日期把时间戳只取日期部分精确到天把时间戳只取时间部分精确到秒把时间戳转化为字符串形式精确到秒取月份第一天精确到天

因为长期的项目积累,自己写了一些计算时间的插件,相比较momoent,我觉得比它好用

</>复制代码 
const ONE_DAY = 86400000
const ensureLength = function (num) {
  // 补全时间YYY-MM-dd HH:MM:ss
  let nlen = num.toString().length
  num = nlen < 2 ? "0" + num : num
  return num
}
const isUndefined = function (s) {
  return s === undefined || s === null || s === ""
}
const _DateUtils = {
  parse (dateStr) {
    if (dateStr instanceof Date) {
      return dateStr
    } else if (/^d+$/.test(dateStr)) {
      return new Date(parseInt(dateStr, 10))
    } else if (dateStr) {
      let dateString = dateStr.replace(/[-:]/g, ",").replace(/s+/g, ",")
      let dateArr = dateString.split(",")
      return new Date(dateArr[0], dateArr[1] - 1, dateArr[2], dateArr[3] || 0, dateArr[4] || 0, dateArr[5] || 0)
    } else if (!dateStr) {
      return dateStr
    }
  },
  toDateString (date, tpl) {
    let locals
    if (isUndefined(date)) {
      date = new Date()
    }
    if (isUndefined(tpl)) {
      tpl = "yyyy-MM-dd"
    }
    date = this.parse(date)
    locals = {
      yyyy: date.getFullYear(),
      YYYY: date.getFullYear(),
      MM: ensureLength(date.getMonth() + 1),
      dd: ensureLength(date.getDate()),
      HH: ensureLength(date.getHours()),
      mm: ensureLength(date.getMinutes()),
      ss: ensureLength(date.getSeconds())
    }
    return tpl.replace(/YYYY|yyyy|MM|dd|HH|mm|ss/g, function ($1) {
      return locals[$1]
    })
  },
  toTimeString (date, tpl) {
    let locals
    if (isUndefined(date)) {
      date = new Date()
    }
    if (isUndefined(tpl)) {
      tpl = "HH:mm:ss"
    }
    locals = {
      HH: ensureLength(date.getHours()),
      mm: ensureLength(date.getMinutes()),
      ss: ensureLength(date.getSeconds())
    }
    return tpl.replace(/HH|mm|ss/g, function ($1) {
      return locals[$1]
    })
  },
  toDateTimeString (date) {
    date = date || new Date()
    date = this.parse(date)
    return this.toDateString(date) + " " + this.toTimeString(date)
  },
  getFirstDate (date) {
    date = date || new Date()
    date = this.parse(date)
    let fitsrDate = new Date(date.getFullYear(), date.getMonth(), 1)
    return this.toDateString(fitsrDate)
  },
  getLastDate (date) {
    date = this.parse(date)
    let nextMonthFirstDate = (new Date(date.getFullYear(), date.getMonth() + 1, 1)).getTime()
    let lastDate = new Date(nextMonthFirstDate - ONE_DAY)
    return this.toDateString(lastDate)
  },
  toMonthString (date) {
    let month
    if (isUndefined(date)) {
      date = new Date()
    }
    date = this.parse(date)
    month = ensureLength(date.getMonth() + 1)
    return (date.getFullYear()) + "-" + month
  },
  getPreMonth (date) {
    let month, year
    if (isUndefined(date)) {
      date = new Date()
    }
    date = this.parse(date)
    year = date.getFullYear()
    month = ensureLength(date.getMonth())
    year = month === "00" ? year - 1 : year
    month = month === "00" ? "12" : month
    return year + "-" + month
  },
  getPreMonthDay (today) {
    if (isUndefined(today)) {
      today = new Date()
    }
    return this.toDateString(today.setMonth(today.getMonth() - 1))
  },
  ago (cnt) {
    let day = new Date().getDate()
    return new Date().setDate(day - cnt)
  },
  getCurrentWeek () {
    let now = new Date()
    let currentDay = now.getDay()
    let start = this.ago(currentDay - 1)
    let end = now
    return [start, end]
  },
  getRecentMonths (cnt) {
    /*
      params{
        cnt : "月",往後推幾個月
      }
    */
    if (isUndefined(cnt)) {
      cnt = 0
    }
    cnt = parseInt(cnt)
    let now = new Date()
    let currentMonth = now.getMonth()
    let year = now.getFullYear()
    let start
    let agoMonth = currentMonth - cnt > 0 ? currentMonth - cnt : currentMonth - cnt + 12
    let agoYear = currentMonth - cnt > 0 ? year : year - 1
    start = new Date(agoYear, agoMonth, 1)
    let end = new Date()
    return [start, end]
  },
  getCurrentQ () {
    let now = new Date()
    let currentMonth = now.getMonth()
    let start
    if (currentMonth < 3) {
      start = now.setMonth(0)
    } else if (currentMonth > 3 && currentMonth < 6) {
      start = now.setMonth(3)
    } else if (currentMonth > 2 && currentMonth < 6) {
      start = now.setMonth(6)
    } else if (currentMonth > 8 && currentMonth < 11) {
      start = now.setMonth(9)
    }
    start = new Date(start).setDate(1)
    let end = new Date()
    return [start, end]
  }
}
/*
params:{
  parse(格式化日期),
  toDateString(把时间戳只取日期部分,精确到天),
  toTimeString(把时间戳只取时间部分,精确到秒),
  toDateTimeString(把时间戳转化为字符串形式,精确到秒),
  getFirstDate(取月份第一天,精确到天),
  getLastDate(取月份最后一天,精确到天),
  toMonthString(月份转化为字符串),
  getPreMonth(取上月份,精确到月),
  getPreMonthDay(取上一月,精确到天),
  ago(前第n天,精确到天),
  getRecentMonths(最近幾個月,從1號開始)
  getCurrentQ(最近一個季度,從1號開始)
}
*/
export default _DateUtils