/**
* Get the difference by the given interval using a filter closure.
* The callback will be called for each period in the given time frame. If the callback returns true the period is
* included as difference, false should be returned otherwise.
*
* @param DateInterval|PHPDateInterval|string|null $dateInterval A DateInterval or PHPDateInterval instance, the
* date interval specification as a string, the date interval relative date and time as a string or null to use
* a zero date interval.
* @param Closure $callback The callback function to call for each period as filter.
* @param DateTime|PHPDateTime|string|null $dateTime [optional] The DateTime or PHPDateTime instance, the date and
* time as a string or null to use the now() date and time.
* @param boolean $absolute [optional] True to get the absolute difference, false otherwise.
*
* @return int|null The difference of the date interval in the given time frame. Null will be returned on failure.
*/
public function diffFiltered($dateInterval, Closure $callback, $dateTime = null, $absolute = true)
{
// Parse the date interval, return null on failure
if (($dateInterval = DateInterval::parse($dateInterval)) === null) {
return null;
}
// Parse the date and time, return null on failure
if (($dateTime = static::parse($dateTime, $this->getTimezone())) === null) {
return null;
}
// Define the start and end times, define whether the value should be inverted
$inverse = !$this->isLessThan($dateTime);
$start = $inverse ? $this : $dateTime;
$end = $inverse ? $dateTime : $start;
// Run the callback for all periods
$period = new DatePeriod($start, $dateInterval, $end);
$values = array_filter(iterator_to_array($period), function (DateTime $date) use($callback) {
return call_user_func($callback, DateTime::instance($date));
});
// Get the difference result
$diff = count($values);
// Return the difference result, inverse the value if needed
return $inverse && !$absolute ? $diff * -1 : $diff;
}
