如何按周过滤器过滤数据数组（）

Question

目前尝试按周过滤我的数据数组，我已经能够很容易地按天过滤，但是我在 x 和 y 之间的日期（例如按周）上苦苦挣扎。

我尝试设置开始日期和结束日期（今天），然后尝试返回小于或等于开始日期和结束日期的日期，但失败了。

数据数组日期格式：dd/mm/yyyy (01/01/2000)

用户将选择使用哪个过滤器（因此 switch() ）案例 7 被过滤 7 天。

computed: {
    appointments: function () {

      var today = new Date();
      var dd = String(today.getDate()).padStart(2, '0');
      var mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
      var yyyy = today.getFullYear();


      var data = this.$store.state.appointments;

      this.filter1_color = "grey";
      this.filter2_color = "grey";

      switch (this.dateFilter) {
        case 0:
        break;

        case 1:
        console.log("case1: " + today)
        return data.filter(word => word.date == today);

        case 7:

        /// WORKING /// (ex. edit)
        var week = [];

        var today = moment();
        var sevenDaysBefore = today.subtract(7, 'days');

        for (var i = 0; i < data.length; i++) {
          let momentDate = moment(data[i].date, 'DD/MM/YYYY')
          let newDate = momentDate.format("DD/MM/YYYY")
          if (momentDate.isBetween(sevenDaysBefore, moment(), null, '[]')) week.push(data[i]);
        }


        return week
        ///

      }


      return data;
    },

我需要过滤数据以仅显示数组中日期等于过去 7 天日期的项目。

Answer 1

您可以使用当前日期的时刻 js 库的方法 isBetween。您可以使用subtract(7, 'days') 减去当前日期的 7 天。

您可以在 Moment js 库文档中查看更多关于 isBetween 方法的信息。该方法的第三个参数是粒度，在您的情况下似乎应该是“天”

const today = moment();
const sevenDaysBefore = moment().subtract(7, 'days');

console.log('Today is ' + today.format('MMM Do YYYY'));
console.log('Is ' + today.format('MMM Do YYYY') + ' included in the last seven days?');
console.log(today.isBetween(sevenDaysBefore, today, 'day', '[]'));

console.log('Is ' + sevenDaysBefore.format('MMM Do YYYY') + ' included in the last seven days?');
console.log(sevenDaysBefore.isBetween(sevenDaysBefore, today, 'day', '[]'));

const eightDaysBefore = moment().subtract(8, 'days');
console.log('Is ' + eightDaysBefore.format('MMM Do YYYY') + ' included in the last seven days?');
console.log(eightDaysBefore.isBetween(sevenDaysBefore, today, 'day', '[]'));

const oneDayAfter = moment().add(1, 'days');
console.log('Is ' + oneDayAfter.format('MMM Do YYYY') + ' included in the last seven days?');
console.log(oneDayAfter.isBetween(sevenDaysBefore, today, 'day', '[]'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.js"></script>

Answer 2

如果您不想或不能使用像 moment.js 这样的库，并且也不介意具有某些限制的临时实现：

注意

我建议使用库来处理Date 对象，尤其是在将字符串解析为日期时。手动操作时可能会出错。如果可能，请使用@f-CJ 的答案

这些部分允许您从字符串创建Date 对象。但是，生成的Date总是转换为本地时间，并且字符串需要具有某种格式（您在问题中显示的格式）。如果您需要UTC 支持，这将不起作用。此外，它不能用于解析具有 ISO 格式的日期字符串。

const OFFSET_TO_UTC = new Date().getTimezoneOffset();

function parseDateString (dateString, sep) {
  var parts = dateString.split(sep);
  return parts.map(n => Number(n));
}

function localizeDate (pattern, parts) {
  return pattern.reduce((acc, pat, i) => {
    switch (pat) {
      case 'd':
        return Object.assign(acc, { day: parts[i] });
      case 'm':
        return Object.assign(acc, { month: parts[i] });
      case 'y':
        return Object.assign(acc, { year: parts[i] });
      default:
        return acc;
    }
  }, {});
}

function toDate (localized) {
  return new Date(
    localized.year,
    localized.month - 1,
    localized.day,
    0, 0 - OFFSET_TO_UTC, 0);
}

function parseDate (pattern, sep, dateString) {
  return toDate(localizeDate(pattern, parseDateString(dateString, sep)));
}


// try it:

const dStringUS = '04/04/2019'; // mm/dd/yyyy
const dStringDE = '04.04.2019'; // dd/mm/yyyy

const dateUS = parseDate(['m', 'd', 'y'], '/', dStringUS);
const dateDE = parseDate(['d', 'm', 'y'], '.', dStringDE);

console.log(dateUS);
console.log(dateDE);

基于它，你可以自己写一个通用的过滤函数：

const OFFSET_TO_UTC = new Date().getTimezoneOffset();

function parseDateString (dateString, sep) {
  var parts = dateString.split(sep);
  return parts.map(n => Number(n));
}

function localizeDate (pattern, parts) {
  return pattern.reduce((acc, pat, i) => {
    switch (pat) {
      case 'd':
        return Object.assign(acc, { day: parts[i] });
      case 'm':
        return Object.assign(acc, { month: parts[i] });
      case 'y':
        return Object.assign(acc, { year: parts[i] });
      default:
        return acc;
    }
  }, {});
}

function toDate (localized) {
  return new Date(
    localized.year,
    localized.month - 1,
    localized.day,
    0, 0 - OFFSET_TO_UTC, 0);
}

function parseDate (pattern, sep, dateString) {
  return toDate(localizeDate(pattern, parseDateString(dateString, sep)));
}



const data = [{
  value: 0,
  date: '04/05/2019'
}, {
  value: 1,
  date: '04/07/2019'
}, {
  value: 2,
  date: '03/07/2019'
}];

function filterByDatePattern (pattern, sep) {
  return function (date, list) {
    return list.filter(item => {
      var itemDate = parseDate(pattern, sep, item.date);
      return itemDate >= date;
    });
  }
}

const onlyUSUntil = filterByDatePattern(['m', 'd', 'y'], '/');
console.log(onlyUSUntil(new Date(2019, 3, 1), data));