How to set closest available date?

Question

Main question: How to set closest available date?

Hi all, i'm using bootstrap-datetimepicker.

I've disabled some days from calendar and sometimes current date in range. So it disables successfully but I want to preset default date into the input value, if I use defaultDate: 'moment' it sets current date (which is disabled).

How to set closest available date?

Does exist any lifehack to resolve it? Or should I make it manually?

This is how it works now:

var $datesDisabled = [];
$.each($dates, function (key, value) {
    $datesDisabled.push(moment(value))
});

// PARAMS TO DATETIMEPICKER
var $params = {
    locale: 'en',
    format: 'DD/MM/YYYY',
    disabledDates: $datesDisabled,
};

// CHECK IF CURRENT DATE IS IN DISABLED ARRAY
if ($.inArray(moment().format('MM/DD/YYYY'), $dates) === -1) {
    // IF NOT PRESET CURRENT DATE
    $params.defaultDate = 'moment';
} else {
    // DO NOT PRESET
    $params.useCurrent = false;
}

$('.datetimepicker').datetimepicker($params);

Answer 1

According to the library documentation, you're not supposed to use defaultDate: 'moment'. They do mention the following:

Accepts: date, moment, string

But it means you can provide a Date object, a moment() object or a date string. The string "moment" is none of those, so it probably defaults to today.

However, you can configure the defaultDate like this:

// Using a date string
$('#my-date-picker').datetimepicker({
  defaultDate: '2016-08-20'
});

// Using a Date object
$('#my-date-picker').datetimepicker({
  defaultDate: new Date('2016-08-20')
});

// Using a moment.js object
$('#my-date-picker').datetimepicker({
  defaultDate: moment('2016-08-20')
});

But if you want to have the defaultDate the closest date according to your disabled dates, you'll have to calculate it by yourself. For such a functionality you could create a recursive function that recalls itself with the given date minus or plus 1 until it finds one that is not disabled.

For example:

var disabled = [
  new Date('2016-01-03'),
  new Date('2016-01-04'),
  new Date('2016-01-05'),
  new Date('2016-01-08')
];

function getClosest(date, disabled, direction) {
  if(!containsDate(disabled, date)) {
    return date;
  } else {
    var prev = getClosest(date.clone().add(direction || -1, 'days'), disabled, direction || -1),
        next = getClosest(date.clone().add(direction || 1, 'days'), disabled, direction || 1);
    if (Math.abs(date.diff(prev, 'days')) > Math.abs(date.diff(next, 'days'))) {
      return next;
    } else {
      return prev;
    }
  }
}

function containsDate(dates, given) {
  return dates.some(function(date) {
    return given.isSame(date, 'day');
  });
}

console.log(getClosest(moment('2016-01-02'), disabled).toDate());
console.log(getClosest(moment('2016-01-03'), disabled).toDate());
console.log(getClosest(moment('2016-01-04'), disabled).toDate());
console.log(getClosest(moment('2016-01-05'), disabled).toDate());
console.log(getClosest(moment('2016-01-06'), disabled).toDate());

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