Can't open downloaded attachments from Gmail API

Question

I feel like I'm missing something stupid...

I'm using the PHP SDK for the new Gmail API to fetch an attachment from an email. I can get the attachment content, but unless it's a text file, I can't open the file after it's been saved. If the attachment is a PDF, it won't render. If it's an excel file, it won't open.

What am I doing wrong?

// this works; I get the attachment body, etc
$data = $g->gmail->users_messages_attachments->get($email_account, $email_message_id, $p->getBody()->getAttachmentId());

$fh = fopen(DOC_ROOT."/file.pdf", "w+");
fwrite($fh, base64_decode($data->data));
fclose($fh);

Answer 1

There may be an issue with decoding the attachment data. Try using this string replace on the attachment data before writing it to a file.

    $data = $g->gmail->users_messages_attachments->get($email_account, $email_message_id, $p->getBody()->getAttachmentId());

    // Converting to standard RFC 4648 base64-encoding
    // see http://en.wikipedia.org/wiki/Base64#Implementations_and_history
    

    $fh = fopen(DOC_ROOT."/file.pdf", "w+");
    fwrite($fh, base64_decode($data->data));
    fclose($fh);

Answer 2

You also need to join the path of where you want to store your file with the filename part of the message payload.

I'm not particularly well versed in php, but in python it would be the equivilent of:

path = ''.join([store_dir, part['filename']])
f = open(path, 'w')
f.write(file_data)
f.close()

Where the file_data is what you have decoded (your $data )

Answer 3

Try the following to decode returned attachment data before writing it to file.

$attachment_data = urlsafe_b64decode(utf8_encode($data->data));

worked for me.