Upload Excel file Google Drive API - php

Question

I am using Google Drive API to upload Excel files. I did the API connection correctly. Create a folder and upload the excel file correctly. I can see both of them in my google drive. But, the excel file is empty.. What am I missing here?
my code is below:
$path = "uploads/school_info.xlsx"; //file that I am uploading, inside a folder of my website.
$folder_id = create_folder("School_".$_POST['submit_uid'], "****folder-id****");
$file_name = "School 1";
$success = insert_file_to_drive( $path, $file_name, $folder_id);
// This will insert file into drive and returns boolean values.
function insert_file_to_drive( $file_path, $file_name, $parent_file_id = null ) {
$service = new Google_Service_Drive( $GLOBALS['client'] );
$file = new Google_Service_Drive_DriveFile();
$file->setName( $file_name );
if( !empty( $parent_file_id ) ){
$file->setParents( [ $parent_file_id ] );
}
$result = $service->files->create(
$file,
array(
'data' => file_get_contents($file_path),
//'mimeType' => 'application/octet-stream',
'mimeType' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', //works but still empty excel
)
);
$is_success = false;
if( isset( $result['name'] ) && !empty( $result['name'] ) ){
$is_success = true;
}
return $is_success;
}

Answer 1

ok I found what was the problem. As I wrote in my code above, I had a relative path
$path = "uploads/school_info.xlsx";
when I changed it to full path like this:
$path = "https://www.example.com/uploads/school_info.xlsx";
everything works as expected
thank you all for your time

Answer 2

Answer
I have successfully uploaded a .xlsx file with the following code. Apparently it is very similar to yours, I just change the mimeType and add the uploadType. Once the file is uploaded, from the UI version of Drive, I can access and view the contents of the file. In case it still fails, please repeat the process by downloading a sample file from here.
Code
$service = new Google_Service_Drive($client);
$file = new Google_Service_Drive_DriveFile();
$file->setName('test.xlsx');
$data = file_get_contents('file_example_XLSX_50.xlsx');
$result = $service->files->create($file, array(
'data' => $data,
'mimeType' => 'application/vnd.ms-excel',
'uploadType' => 'multipart'
));