更新moment.js的持续时间

Question

Is it possible to update a moment.js duration using the standard methods without using the add/subtract methods?

For example, create the moment:

d = moment.duration({
    seconds: 34,
    minutes: 55,
    hours: 2,
});

Then update only the minutes but keep the seconds and hours the same?

I can do something like this:

newD = moment.duration({
    seconds: value.seconds(),
    minutes: 32,
    hours: value.hours(),
});

Or work out whether I need to add/subtract from the original and then use:

d.subtract(23).minutes();

But I feel like I'm missing something obvious here.

Rather than add/subtract from the moment, I'd like to replace one of the values stores in the object as seen in _data:

 _data: [object Object] {
     days: 0,
     hours: 1,
     milliseconds: 0,
     minutes: 20,
     months: 0,
     seconds: 0,
     years: 0
 },

Ie the equivalent of:

d._data.minutes = 3;

But it needs to also update the other properties of the object.

Answer 1

Looking at momentjs API (and code), there seems to be no setter methods on duration object for time units (hours, minutes, seconds etc). All momentjs provides for these time units is getters. So a good way to do this is the way you did it in the question itself, creating a new duration object using the values from an existing one.

var d = moment.duration({
    seconds: 34,
    minutes: 55,
    hours: 2
});

var newD = moment.duration({
    seconds: d.value(),
    minutes: 32,
    hours: d.value()
});

Updating the underlying _data property seems to update the specific time unit, but it doesn't update the duration object itself. So other methods like humanize do not provide us with the updated value.

var d = moment.duration({
    seconds: 34,
    minutes: 55,
    hours: 2
});

d.humanize() // '3 hours'
d._data.hours = 5;
d.hours() // 5 -> This is being updated
d.humanize() // '3 hours' -> This one isn't