(Perl) Download GMail Message Attachment by ID

Demonstrates how to download a GMail email attachment by the attachment ID.

For more information, see https://developers.google.com/gmail/api/v1/reference/users/messages/attachments/get

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$http = chilkat::CkHttp->new();

$http->put_AuthToken("ACCESS_TOKEN");
$http->put_Accept("application/json");

# See the following example:  Get GMail Message (format=full)
# It shows how to download an email by message ID, and it shows how to parse the JSON
# response which includes attachment names, ids, and other information.

# This example will assume we already have the attachment id and filename.

# This is the attachment ID for a file named "helloWorld.pdf".
$attachmentId = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU";

$messageId = "1712bc1dc22da2a2";

$http->SetUrlVar("messageId",$messageId);
$http->SetUrlVar("attachmentId",$attachmentId);

$url = "https://www.googleapis.com/gmail/v1/users/userId/messages/{$messageId}/attachments/{$attachmentId}";

# When we download, the response is JSON that contains the attachment data base64url encoded, like this:
# {
#  "size": 934,
#  "data": "JVBERi0xLjM ... CiUlRU9GCg=="
# }

$outputFilePath = "qa_output/helloWorld.pdf";

# Download into a StringBuilder.
$sbJson = chilkat::CkStringBuilder->new();
$success = $http->DownloadSb($url,"utf-8",$sbJson);
if ($success == 0) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

if ($http->get_LastStatus() != 200) {
    # Something failed.
    # the JSON contains an error message.
    print $sbJson->getAsString() . "\r\n";
    exit;
}

# Load into a Chilkat JSON object.
$json = chilkat::CkJsonObject->new();
$success = $json->LoadSb($sbJson);

# Extract the base64url data into a BinData.
$bd = chilkat::CkBinData->new();
$success = $json->BytesOf("data","base64url",$bd);

# Save the data to a file.
$success = $bd->WriteFile("qa_output/helloWorld.pdf");

print "Success." . "\r\n";