/**
* Return an array of available items, suitable for dropDownList()
* @param number $root ID of root nodes to retrieve
* @param string $level The level of tree to retrieve
* @return array $res An associate array with key - value
*/
public static function options($root = 0, $level = NULL)
{
$res = [];
if ($root instanceof self) {
$res[$root->id] = str_repeat('-', $root->level) . ' ' . $root->title;
if ($level) {
foreach ($root->children()->all() as $childRoot) {
$res += self::options($childRoot, $level - 1);
}
} elseif (is_null($level)) {
foreach ($root->children()->all() as $childRoot) {
$res += self::options($childRoot, NULL);
}
}
} elseif (is_scalar($root)) {
if ($root == 0) {
foreach (self::find()->roots()->all() as $rootItem) {
if ($level) {
$res += self::options($rootItem, $level - 1);
} elseif (is_null($level)) {
$res += self::options($rootItem, NULL);
}
}
} else {
$root = self::find($root);
if ($root) {
$res += self::options($root, $level);
}
}
}
return $res;
}
