function datetime_range_years

Specifies the start and end year to use as a date range.

Handles a string like -3:+3 or 2001:2010 to describe a dynamic range of minimum and maximum years to use in a date selector.

Centers the range around the current year, if any, but expands it far enough so it will pick up the year value in the field in case the value in the field is outside the initial range.

Parameters

string $string: A min and max year string like '-3:+1' or '2000:2010' or '2000:+3'.

object $date: (optional) A date object to test as a default value. Defaults to NULL.

Return value

array A numerically indexed array, containing the minimum and maximum year described by this pattern.

File

drupal/core/modules/datetime/datetime.module, line 1092

Field hooks to implement a simple datetime field.

Code

function datetime_range_years($string, $date = NULL) {
  $this_year = date_format(new DrupalDateTime(), 'Y');
  list($min_year, $max_year) = explode(':', $string);

  // Valid patterns would be -5:+5, 0:+1, 2008:2010.
  $plus_pattern = '@[\\+|\\-][0-9]{1,4}@';
  $year_pattern = '@^[0-9]{4}@';
  if (!preg_match($year_pattern, $min_year, $matches)) {
    if (preg_match($plus_pattern, $min_year, $matches)) {
      $min_year = $this_year + $matches[0];
    }
    else {
      $min_year = $this_year;
    }
  }
  if (!preg_match($year_pattern, $max_year, $matches)) {
    if (preg_match($plus_pattern, $max_year, $matches)) {
      $max_year = $this_year + $matches[0];
    }
    else {
      $max_year = $this_year;
    }
  }

  // We expect the $min year to be less than the $max year. Some custom values
  // for -99:+99 might not obey that.
  if ($min_year > $max_year) {
    $temp = $max_year;
    $max_year = $min_year;
    $min_year = $temp;
  }

  // If there is a current value, stretch the range to include it.
  $value_year = $date instanceof DrupalDateTime ? $date
    ->format('Y') : '';
  if (!empty($value_year)) {
    $min_year = min($value_year, $min_year);
    $max_year = max($value_year, $max_year);
  }
  return array(
    $min_year,
    $max_year,
  );
}