Laravel自定义表单选择宏

Question

Please help me with this custom select macro that I've got from this website . This code is working fine when you add the start value less that the end value.

Form::macro('selectRangeWithDefault', function($name, $start, $end, $selected = null, $default = null, $attributes = [])
{
  if ($default === null) {
    return Form::selectRange($name, $start, $end, $selected, $attributes);
  }
  $items = [];
  if (!in_array($default, $items)) {
    $items[''] = $default;
  }

  if($start > $end) {
    $interval = -1;
    $startValue = $end;
    $endValue = $start;
  }  else {
    $interval = 1;
    $startValue = $start;
    $endValue = $end;
  }

  for ($i=$startValue; $i<$endValue; $i+=$interval) {
    $items[$i . ""] = $i;
  }

  $items[$endValue] = $endValue;

  return Form::select($name, $items, isset($selected) ? $selected : $default, $attributes);
});

When adding greater than value from start value and less in the end value it breaks. Please help me fix this code guys

Answer 1

If your startvalue is bigger than your endvalue, you set 'start=end', and 'end=start'. If you want (need) to loop from the start to the endvalue, you need to increase every time with '1'. However, if you set the interval to '-1', and you begin from your startvalue (which is now smaller than the endvalue), your loop will never stop.

change

if($start > $end) {  
$interval = -1;
$startValue = $end; 
$endValue = $start;

into

if($start > $end) {
$interval = 1;
$startValue = $end;
$endValue = $start;

to make it work.

edit: explanation