Google Drive PHP API Download file - php

Question

I have problem with downloading file from google drive using php api. I managed to upload file to google drive in folder and $service->files->insert returns to me File Resource which has attribute downloadUrl but when I redirect to that url, it does not work. I get 401 error. Why is this happening? What do I need to do make this work?
Here's code:
<?php
require_once 'vendor/autoload.php';
session_start();
$client_id = 'xxx';
$client_secret = 'yyy';
$redirect_uri = 'http://localhost/GoogleDrive/code.php';
$client = new Google_Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);
$client->setRedirectUri($redirect_uri);
$client->addScope("https://www.googleapis.com/auth/drive");
$service = new Google_Service_Drive($client);
$authUrl = $client->createAuthUrl();
header("Location: $authUrl");
and code.php
require_once 'vendor/autoload.php';
session_start();
$client_id = 'xxx';
$client_secret = 'yyy';
$redirect_uri = 'http://localhost/GoogleDrivePayload/code.php';
$client = new Google_Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);
$client->setRedirectUri($redirect_uri);
$client->setApprovalPrompt('force');
$client->addScope("https://www.googleapis.com/auth/drive");
$service = new Google_Service_Drive($client);
if (isset($_GET['code'])) {
$client->authenticate($_GET['code']);
$_SESSION['upload_token'] = $client->getAccessToken();
$redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}
if (isset($_SESSION['upload_token']) && $_SESSION['upload_token']) {
$client->setAccessToken($_SESSION['upload_token']);
if ($client->isAccessTokenExpired()) {
unset($_SESSION['upload_token']);
}
}
if ($client->getAccessToken()) {
$file = new Google_Service_Drive_DriveFile();
$file->setTitle("hello.exe");
$file->setDescription("LALALALALAL");
$file->setMimeType('application/x-msdos-program');
$parent = new Google_Service_Drive_ParentReference();
$parent->setId("zzz");
$file->setParents(array($parent));
$data = file_get_contents('hello.exe');
$createdFile = $service->files->insert($file, array(
'data' => $data,
'mimeType' => 'application/x-msdos-program',
'uploadType' => 'multipart',
"visibility" => "DEFAULT"
));
header("Location: " . $createdFile->downloadUrl);
}

Answer 1

downloadUrl is exactly what it says, ie. the URL your PHP app can use to fetch the file. You would almost never redirect a browser to that URL, and if you did (you probably really don't want to), you'll need append a valid access token to the URL to fix the 401.