PHP Convert SimpleXML object to Array

public function simpleXMLToArray(SimpleXMLElement $xml,$attributesKey=null,$childrenKey=null,$valueKey=null){

    if($childrenKey && !is_string($childrenKey)){$childrenKey = '@children';}

    if($attributesKey && !is_string($attributesKey)){$attributesKey = '@attributes';}

    if($valueKey && !is_string($valueKey)){$valueKey = '@values';}

    $return = array();

    $name = $xml->getName();

    $_value = trim((string)$xml);

    if(!strlen($_value)){$_value = null;};

    if($_value!==null){

        if($valueKey){$return[$valueKey] = $_value;}

        else{$return = $_value;}

    }

    $children = array();

    $first = true;

    foreach($xml->children() as $elementName => $child){

        $value = $this->simpleXMLToArray($child,$attributesKey, $childrenKey,$valueKey);

        if(isset($children[$elementName])){

            if(is_array($children[$elementName])){

                if($first){

                    $temp = $children[$elementName];

                    unset($children[$elementName]);

                    $children[$elementName][] = $temp;

                    $first=false;

                }

                $children[$elementName][] = $value;

            }else{

                $children[$elementName] = array($children[$elementName],$value);

            }

        }

        else{

            $children[$elementName] = $value;

        }

    }

    if($children){

        if($childrenKey){$return[$childrenKey] = $children;}

        else{$return = array_merge($return,$children);}

    }

    $attributes = array();

    foreach($xml->attributes() as $name=>$value){

        $attributes[$name] = trim($value);

    }

    if($attributes){

        if($attributesKey){$return[$attributesKey] = $attributes;}

        else{$return = array_merge($return, $attributes);}

    }

    return $return;

}