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我不太擅长处理datetime。我将momentjs用于离子应用程序来操纵时间，但我想实现一些我做不到的事情。

我为此使用了一个管道，我想根据过去的天数或几周、几个月或几年来显示。使用相对时间会帮助我喜欢momentjs的fromNow()方法和calendar()。但就我而言，我会有多个.conditions

这是我的管道下面的示例代码

transform(value: Date | moment.Moment, dateFormat: string): any {
    if (moment(value) < moment(value).subtract(7, 'days')) {
      return moment(value).format('llll') // Use this format if weeks, months or years has passed
    } else if (moment(value) < moment(value).subtract(1, 'days')) {
      return moment(value).calendar(); // Use calendar time if 1 day has passed
    } else {
      return moment(value).fromNow(); // Use relative time if within 24 hours
    }
  }

如果几秒钟、几分钟或几小时已经过去，直到 24 小时，我将使用该fromNow()方法，但当几天过去时，我将使用 the calendar()，如果几周、几个月或几年过去，则使用 this format('llll')。

有人可以为我解释一下吗？

提前致谢。

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2 回答 2

4

据我了解，您想根据某个特定时刻距 离多长时间now做出决定。您似乎有 3 个案例：> 7 天，> 1 天，<1 天。

Momentjs 提供了一个非常有用的diff方法。因此，您可以执行以下操作：

  var currDate = moment.now();
  var dateToTest = moment(val);
  // if dateToTest will always be in past, use currDate as the base to diff, else 
  be prepared to handle the negative outcomes. 
  var result = currDate.diff(dateToTest, 'days')


window.onload = function() {
  console.log("Test Cases: ")
  console.log("Input: Date is 2 minutes behind")
  dateThing("2018-07-20T12:02:54+00:00");
  
  console.log("Input: Date is few hours behind")
  dateThing("2018-07-20T07:02:54+00:00");
  
  console.log("Input: Date is 23 hours 59 minutes behind")
  dateThing("2018-07-19T12:03:54+00:00");
  
  console.log("Input: Date is 24 hours behind")
  dateThing("2018-07-19T12:04:54+00:00");
  
  console.log("Input: Date is 2 days behind")
  dateThing("2018-07-18T12:04:54+00:00");
  
  console.log("Input: Date is 12 days behind")
  dateThing("2018-07-08T12:04:54+00:00");
}

dateThing = function(val) {
  // for now freezing the "now" so that precise testcases can be written.
  // var currDate = moment.now();
  var currDate = moment("2018-07-20T12:04:54+00:00")
  var dateToTest = moment(val);
  // if dateToTest will always be in past, use currDate as the base to diff, else be prepared to handle the negative outcomes. 
  var result = currDate.diff(dateToTest, 'days')
  if (result > 7) {
    console.log("Output: date is more than 1 week behind")
  } else if (result > 1) {
    console.log("Output: date is more than 1 day but less than 1 week behind")
  } else {
    console.log("Output: date is less  than 1 day behind")
  }
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>

请运行上面的代码片段来查看边界情况的行为，如果它不准确，您可以用分钟进行 diff 并反转流程。

于 2018-07-20T09:12:19.137 回答
0

你去吧。:)

function transformDate(givenDate) {
    if (moment().subtract(7, 'days').valueOf() > moment(givenDate).valueOf()) {
      return moment(givenDate).format('llll');
    } else if (moment().subtract(1, 'days').valueOf() > moment(givenDate).valueOf()) {
      return moment(givenDate).calendar();
    } else {
      return moment(givenDate).fromNow();
    }
}
// current time
console.log(transformDate(new Date()));
// 8 days before this answer was posted 
console.log(transformDate(new Date(1531394211385))); 
// 2 days before this answer was posted
console.log(transformDate(new Date(1531912692803))); 
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.20.1/moment.min.js"></script>

于 2018-07-20T11:19:26.447 回答