@febe95/vue-functional-calendar/src/assets/js/helpCalendar.js

Lightweight, high-performance calendar component based on Vue.js

Date.prototype.getWeekNumber = function(sundayStart) {
  if (!sundayStart) {
    // ISO week date weeks start on monday
    // so correct the day number
    let dayNumber = (this.getDay() + 6) % 7
    // Set the target to the thursday of this week so the
    // target date is in the right year
    this.setDate(this.getDate() - dayNumber + 3)
  }

  let january4 = new Date(this.getFullYear(), 0, 4)
  return Math.ceil(((this - january4) / 86400000 + january4.getDay() + 1) / 7)
}

export default class helpCalendar {
  constructor(sundayStart, leftAndRightDays, dateFormat, dayNames) {
    this.sundayStart = sundayStart
    this.leftAndRightDays = leftAndRightDays
    this.dateFormat = dateFormat
    this.dayNames = dayNames
  }

  formatDate(date) {
    let day = date.getDate()
    let month = date.getMonth() + 1
    let year = date.getFullYear()

    let formattedDate = this.dateFormat.replace('dd', day.toString())
    formattedDate = formattedDate.replace('mm', month.toString())
    formattedDate = formattedDate.replace('yyyy', year.toString())
    return formattedDate.split(' ')[0]
  }

  getDateFromFormat(date) {
    let format = this.dateFormat.split(' ')[0]
    date = date.split(' ')[0]
    if (format.indexOf('/') !== -1) {
      format = format.split('/')
      date = date.split('/')
    } else if (format.indexOf('-') !== -1) {
      format = format.split('-')
      date = date.split('-')
    } else if (format.indexOf('.') !== -1) {
      format = format.split('.')
      date = date.split('.')
    } else {
      throw new Error('Your date format not valid. Please read documentation.!')
    }

    let year = format.indexOf('yyyy')
    let month = format.indexOf('mm')
    let day = format.indexOf('dd')
    return new Date(date[year], date[month] - 1, date[day])
  }

  checkValidDate(val) {
    val = this.getDateFromFormat(val)

    if (val != 'Invalid Date') {
      return true
    }

    return false
  }

  getWeeksInMonth(month, year) {
    let weeks = [],
      firstDate = new Date(year, month, 1),
      lastDate = new Date(year, month + 1, 0),
      numDays = lastDate.getDate()

    let start = 1

    let end = !this.sundayStart
      ? firstDate.getDay() === 0
        ? 1
        : 7 - firstDate.getDay() + 1
      : 7 - firstDate.getDay()

    while (start <= numDays) {
      weeks.push({
        year,
        start,
        end,
        number: new Date(year, month, start).getWeekNumber(this.sundayStart),
        days: []
      })
      start = end + 1
      end = end + 7
      if (end > numDays) end = numDays
    }
    return {
      weeks,
      month: lastDate.getMonth(),
      year: lastDate.getFullYear()
    }
  }

  getLeftMonthDays(month, year) {
    let weeks = this.getWeeksInMonth(month, year)
    let firstWeek = weeks.weeks[0]
    let weekDaysCount = firstWeek.end - firstWeek.start + 1

    let days = []
    let finalYear = 0
    let finalMonth = 0

    if (weekDaysCount !== 7) {
      let weeksLeftMonth = this.getWeeksInMonth(month - 1, year)

      let leftMonthLastWeek =
        weeksLeftMonth.weeks[weeksLeftMonth.weeks.length - 1]

      for (let i = leftMonthLastWeek.start; i <= leftMonthLastWeek.end; i++) {
        days.push(i)
      }

      finalMonth = weeksLeftMonth.month
      finalYear = weeksLeftMonth.year
    }

    return { days: days.reverse(), month: finalMonth, year: finalYear }
  }

  getRightMonthDays(month, year) {
    let weeks = this.getWeeksInMonth(month, year)
    let lastWeek = weeks.weeks[weeks.weeks.length - 1]

    let weekDaysCount = lastWeek.end - lastWeek.start + 1

    let days = []
    let finalYear = 0
    let finalMonth = 0

    if (weekDaysCount !== 7) {
      let weeksRightMonth = this.getWeeksInMonth(month + 1, year)
      let rightMonthFirstWeek = weeksRightMonth.weeks[0]

      for (
        let i = rightMonthFirstWeek.start;
        i <= rightMonthFirstWeek.end;
        i++
      ) {
        days.push(i)
      }

      finalMonth = weeksRightMonth.month
      finalYear = weeksRightMonth.year
    }

    return { days, month: finalMonth, year: finalYear }
  }

  getFinalizedWeeks(month, year) {
    let monthWeeks = this.getWeeksInMonth(month, year)
    let leftMonthDays = this.getLeftMonthDays(month, year)
    let rightMonthDays = this.getRightMonthDays(month, year)

    // Push Current Month Week days
    monthWeeks.weeks.forEach(week => {
      for (let i = week.start; i <= week.end; i++) {
        week.days.push({
          day: i,
          month: monthWeeks.month,
          year: monthWeeks.year,
          hide: false,
          hideLeftAndRightDays: false
        })
      }
    })

    // Left month days
    if (leftMonthDays.days.length) {
      leftMonthDays.days.forEach(day => {
        let hideLeftAndRightDays = false

        if (!this.leftAndRightDays) {
          day = ''
          hideLeftAndRightDays = true
        }

        monthWeeks.weeks[0].days.unshift({
          day,
          month: leftMonthDays.month,
          year: leftMonthDays.year,
          hide: true,
          hideLeftAndRightDays: hideLeftAndRightDays
        })
      })
    }

    // Right month days
    if (rightMonthDays.days.length) {
      rightMonthDays.days.forEach(day => {
        let hideLeftAndRightDays = false

        if (!this.leftAndRightDays) {
          day = ''
          hideLeftAndRightDays = true
        }

        monthWeeks.weeks[monthWeeks.weeks.length - 1].days.push({
          day,
          month: rightMonthDays.month,
          year: rightMonthDays.year,
          hide: true,
          hideLeftAndRightDays: hideLeftAndRightDays
        })
      })
    }

    // Remove Week Year
    monthWeeks.weeks.forEach(week => {
      delete week.year
    })

    return monthWeeks.weeks
  }

  mask(value) {
    let dayLength = this.getDateFromFormat(value)
      .getDate()
      .toString().length
    let month = this.getDateFromFormat(value).getMonth()

    let dayMask = '00'
    if (dayLength === 1) {
      dayMask = '0'
    }

    let monthMask = '00'
    if (month + 1 <= 9) {
      monthMask = '0'
    }

    let mask = this.dateFormat
      .replace('dd', dayMask)
      .replace('mm', monthMask)
      .replace('yyyy', '0000')
    // eslint-disable-next-line
    let literalPattern = /[0\*]/
    let numberPattern = /[0-9]/
    let newValue = ''

    for (let vId = 0, mId = 0; mId < mask.length; ) {
      if (mId >= value.length) break

      // Number expected but got a different value, store only the valid portion
      if (mask[mId] === '0' && value[vId].match(numberPattern) == null) {
        break
      }

      // Found a literal
      while (mask[mId].match(literalPattern) == null) {
        if (value[vId] === mask[mId]) break
        newValue += mask[mId++]
      }

      newValue += value[vId++]

      mId++
    }

    return newValue
  }
}