Why Google_Service_Drive type is undefined

I was stuck with this problem as well. I was trying to connect Google Drive with my Laravel project. My goal was to allow users to connect their Google Drive accounts so they can upload, download, and view a list of their files directly from the application.

To get the class :

remove the "_" and replace it with "\"

use Google_Client;
use Google\Service\Drive;
use Google\Client;




function listFiles($clientId)
    {
       $clientId = (int) $clientId;
       $client = $this->getClient($clientId);
       $service = new \Google\Service\Drive($client);
       $files = $service->files->listFiles([
                'pageSize' => 10,
                'fields' => 'files(id, name, mimeType)'
            ]);

       return $files->getFiles();
    }


function uploadToDrive(Request $request)
    {
        $uploadedFile = $request->file('file');
        $client = $this->getClient($request->client_id);

        $service = new \Google\Service\Drive($client);
        $fileMetadata = new \Google\Service\Drive\DriveFile([
                'name' => $uploadedFile->getClientOriginalName()
            ]);

        $file = $service->files->create($fileMetadata, [
                'data' => file_get_contents($uploadedFile->getRealPath()),
                'mimeType' => $uploadedFile->getClientMimeType(),
                'uploadType' => 'multipart',
                'fields' => 'id, name'
            ]);

        return $file;
    }


function downloadDriveFile(Request $request)
    {
      $client = $this->getClient($request->client_id);
      $service = new \Google\Service\Drive($client);
      $file = $service->files->get($request->file_id, ['fields' => 'name,   mimeType']);

      $response = $service->files->get($request->file_id, ['alt' => 'media']);

       return response()->streamDownload(function () use ($response) {
                echo $response->getBody();
            }, $file->getName(), [
                'Content-Type' => $file->getMimeType()
            ]);
    }


function getClient($clientId)
    {
        $integration = CloudIntegration::where('user_id', $clientId)
            ->where('provider', 'google_drive')->first();

        if (!$integration) {
            return $this->responseWithError(null, "Client not found", 404);
        }
        $token = json_decode($integration->access_token, true);
        // $token = $integration->access_token;

        $client = new Google_Client();
        $client->setClientId(config('services.google.client_id'));
        $client->setClientSecret(config('services.google.client_secret'));
        $client->setRedirectUri(config('services.google.redirect'));

        $client->setAccessToken($token);

        if ($client->isAccessTokenExpired()) {
            $newToken = $client->fetchAccessTokenWithRefreshToken($integration->refresh_token);
            $integration->update([
                'access_token' => json_encode($newToken),
                'access_token_expires_in' => now()->addSeconds($newToken['expires_in'])
            ]);
            $client->setAccessToken($newToken);
        }
        return $client;
    }

I believe that format is an older format and the newer version uses namespaces, for example

require ("path_to_google_vendor/autoload.php")
//$client is \Google\Client
$service=new \Google\Service\Drive($client);

//Create a folder in root of google drive
$file=new \Google\Service\Drive();
$file->setMimeType('application/vnd.google-apps.folder');
$folder = $service->files->create($file);

A lot of old examples would use the _ version : Google_Service_Drive. For the entire google API you can replace the _ with a \ to get the namespaced version