Retrieve inline images from gmail api? - gmail-api

Question

I'm retrieving messages from my Gmail using Gmail API. specifically, the email with Hangouts conversations using this url: https://www.googleapis.com/gmail/v1/users/me/messages?q=in:chats
When I enter in a message, I see this structure
{
"id": "1555561f7b8e1sdf56b",
"threadId": "155552511dfsd83ce98",
"labelIds": [
"CHAT"
],
"snippet": "df",
"historyId": "270812",
"internalDate": "1466016331704",
"payload": {
"partId": "",
"mimeType": "text/html",
"filename": "",
"headers": [
{
"name": "From",
"value": "\"Oscar J. Irún\" <Oscarjiv91#gmail.com>"
}
],
"body": {
"size": 2,
"data": "ZGY="
}
},
"sizeEstimate": 100
}
as you can see, the body message is "df". Everything it's ok so far.
The problem comes when the Hangout message is an image. The snippet field is empty, and it doesnt show any attachment in the message. This is an example:
{
"id": "155558233274d78c91",
"threadId": "15fd5552511d83ce98",
"labelIds": [
"CHAT"
],
"snippet": "",
"historyId": "27sd0827",
"internalDate": "1466018445133",
"payload": {
"mimeType": "text/html",
"filename": "",
"headers": [
{
"name": "From",
"value": "\"Oscar J. Irún\" <Oscarjiv91#gmail.com>"
}
],
"body": {
"size": 0,
"data": ""
}
},
"sizeEstimate": 100
}
I need to retrieve this inline images. Any help will be appreciated!

Answer 1

You can retrieve attachments by using Users.messages.attachments:get. Take note that this request requires authorization. All requests to the Gmail API must be authorized by an authenticated user. Gmail uses the OAuth 2.0 protocol for authenticating a Google account and authorizing access to user data.
HTTP request
GET https://www.googleapis.com/gmail/v1/users/userId/messages/messageId/attachments/id
public static void getAttachments(Gmail service, String userId, String messageId)
throws IOException {
Message message = service.users().messages().get(userId, messageId).execute();
List<MessagePart> parts = message.getPayload().getParts();
for (MessagePart part : parts) {
if (part.getFilename() != null && part.getFilename().length() > 0) {
String filename = part.getFilename();
String attId = part.getBody().getAttachmentId();
MessagePartBody attachPart = service.users().messages().attachment().
get(userId, messageId, attId).execute();
byte[] fileByteArray = Base64.decodeBase64(attachPart.getData());
FileOutputStream fileOutFile =
new FileOutputStream("directory_to_store_attachments" + filename);
fileOutFile.write(fileByteArray);
file OutFile.close();
}
}
}

Answer 2

JUST FYI for PHP the solution is something similar to this:
base64_decode(strtr($gmail->service->users_messages_attachments->get('me', $message->id, $arrPart['body']['attachmentId'])->data,'-_', '+/'));