Simple YouTube API v3 class

<?php
//==> usage
// youtube data retrieving
$youtube = new YouTubeAPI();
$youtube->setAPIKey($APIKey);

// all videos data
$videos = $youtube->getLatestUploads("ChannelName");
/*
 Notice: sorted by date by default, latest on top
         If you want to have the latest on the bottom,
         just reverse the array using the command:
           $videos = array_reverse($videos);
*/


//==> class
class YouTubeAPI {

    private $api;

    // API
    public function setAPIKey($api)
    {
        $this->api = $api;
    }

    public function getAPIKey()
    {
        return $this->api;
    }

    // VIDEOS
    public function getLatestUploads($channel)
    {
        $playlistId = $this->getPlaylistUploads($channel);
        return $this->getPlaylistVideos($playlistId);
    }

    public function getPlaylistUploads($username)
    {
        return $this->getRelatedPlaylists($username, "uploads");
    }

    public function getPlaylistVideos($playlistId, $maxResults=30)
    {
        $url = $this->getUrl("playlistItems", array(
            "part"       => "snippet",
            "order"      => "date",
            "maxResults" => $maxResults,
            "playlistId" => $playlistId,
        ));
        $data = $this->getData($url);
        return $data;
    }

    public function getRelatedPlaylists($username=null, $playlist="uploads")
    {
        // possible values: likes, uploads
        if($username === null) {
            return null;
        }

        $url = $this->getUrl("channels", array(
            "part"        => "contentDetails",
            "forUsername" => $username,
        ));

        $data = $this->getData($url);

        $PID = @$data["items"][0]["contentDetails"]["relatedPlaylists"][$playlist];
        if(empty($PID)) {
            $PID = null;
        }

        return $PID;
    }

    // DATA
    private function getUrl($service, $data)
    {
        if(empty($data["key"])) {
            $data["key"] = $this->getAPIKey();
        }
        $query = http_build_query($data);
        $url = sprintf("https://www.googleapis.com/youtube/v3/%s?%s", $service, $query);
        return $url;
    }

    private function getData($url)
    {
        $ch = curl_init();
        curl_setopt_array($ch, array(
            CURLOPT_URL => $url,
            CURLOPT_PORT => 443,
            CURLOPT_PROTOCOLS => CURLPROTO_HTTPS,
            CURLOPT_SSLVERSION => CURL_SSLVERSION_TLSv1,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_CONNECTTIMEOUT => 5,
            CURLOPT_AUTOREFERER => false,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_USERAGENT => "pkern.at VideoFeedRetriever",
        ));
        $data = curl_exec($ch);
        curl_close($ch);

        $json = json_decode($data, true);
        if(is_array($json)) {
            return $json;
        }else{
            return $data;
        }
    }
}
?>