摘要：因為長期的項目積累自己寫了一些計算時間的插件相比較我覺得比它好用補全時間月往後推幾個月格式化日期把時間戳只取日期部分精確到天把時間戳只取時間部分精確到秒把時間戳轉(zhuǎn)化為字符串形式精確到秒取月份第一天精確到天

因為長期的項目積累,自己寫了一些計算時間的插件,相比較momoent,我覺得比它好用

const ONE_DAY = 86400000
const ensureLength = function (num) {
  // 補全時間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(把時間戳只取日期部分,精確到天),
  toTimeString(把時間戳只取時間部分,精確到秒),
  toDateTimeString(把時間戳轉(zhuǎn)化為字符串形式,精確到秒),
  getFirstDate(取月份第一天,精確到天),
  getLastDate(取月份最后一天,精確到天),
  toMonthString(月份轉(zhuǎn)化為字符串),
  getPreMonth(取上月份,精確到月),
  getPreMonthDay(取上一月,精確到天),
  ago(前第n天,精確到天),
  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