Obj::toArray() 

public function toArray ( $obj, $depth = 3, $fields = [], $addClass = false )
{
	if ($obj === null) {
		return null;
	}
	$isSimpleType = $this->isSimpleType( gettype($obj) );
	$isStorage = !$isSimpleType && $this->isStorage($obj);
	if ($depth < 0) {
		return $isSimpleType && !is_array($obj) ? $obj : self::END_OF_RECURSION;
	}
	if ($isSimpleType && !is_array($obj)) {
		return $obj;
	}
	$type = is_object($obj) ? get_class($obj) : false;
	$final = [];
	$depth--;
	if (is_a($obj, \TYPO3\CMS\Extbase\Persistence\Generic\QueryResult::class)) {
		$obj = $obj->toArray();
	} else if (is_a($obj, \DateTime::class)) {
		// DateTime in UTC konvertieren
		$utc = $obj->getTimestamp();
		return $utc;
	} else if ($isStorage) {
		// StorageObject in einfaches Array konvertieren
		$obj = $this->forceArray( $obj );
		if ($addClass) $obj['__class'] = ObjectStorage::class;
	} else if (\nn\t3::Obj()->isSysCategory($obj)) {
		//$categoryData = ['uid' => $obj->getUid(), 'title'=>$obj->getTitle(), 'parent'=>$parent];
		$categoryData = [];
		foreach ($this->getKeys($obj) as $k) {
			if ($k == 'parent') {
				$categoryData[$k] = $this->toArray( $obj->getParent(), $depth, $fields, $addClass );
				continue;
			}
			$categoryData[$k] = ObjectAccess::getProperty($obj, $k);
		}
		if ($addClass) $categoryData['__class'] = $type;
		return $categoryData;
	} else if (\nn\t3::Obj()->isFalFile($obj)) {
		// SysFile in Array konvertieren
		$falData = ['uid' => $obj->getUid(), 'title'=>$obj->getTitle(), 'publicUrl'=>$obj->getPublicUrl()];
		if ($addClass) $falData['__class'] = $type;
		return $falData;
	} else if (\nn\t3::Obj()->isFileReference($obj)) {
		// FileReference in einfaches Array konvertieren
		$map = ['uid', 'pid', 'title', 'alternative', 'link', 'description', 'size', 'publicUrl', 'crop', 'type'];
		$falData = [];
		if ($originalResource = $obj->getOriginalResource()) {
			$props = $originalResource->getProperties();
			$props['publicUrl'] = $originalResource->getPublicUrl();
			foreach ($map as $k=>$v) {
				$falData[$v] = $props[$v];
			}
		}
		// Falls FAL nicht über Backend erzeugt wurde, fehlt evtl. das Feld "crop". Also: mit default nachrüsten
		if (!$falData['crop']) {
			$falData['crop'] = json_encode(['default'=>['cropArea' => ['x'=>0, 'y'=>0, 'width'=>1, 'height'=>1]]]);
		}
		if ($addClass) $falData['__class'] = FalFileReference::class;
		return $falData;
	} else if ($type) {
		// Alle anderen Objekte
		$keys = $fields ?: $this->getKeys($obj);
		foreach ($keys as $field) {
			$val = $this->prop($obj, $field);
			$val = $this->toArray($val, $depth, $fields, $addClass);
			if ($val === self::END_OF_RECURSION) continue;
			$final[$field] = $val;
		}
		return $final;
	}
	foreach ($obj as $k=>$v) {
		$val = $this->toArray( $v, $depth, $fields, $addClass );
		if ($val === self::END_OF_RECURSION) continue;
		$final[$k] = $val;
	}
	return $final;
}