Question

Update It seems to be the way untagged responses are handled by twisted, the only example I have found seem to iterate through the data received and somehow collect the response to their command though I am not sure how…

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I am trying to implement the IMAP4 quota commands as defined in RFC 2087 ( https://www.rfc-editor.org/rfc/rfc2087 ).

Code – ImapClient

class SimpleIMAP4Client(imap4.IMAP4Client):
    """
        A client with callbacks for greeting messages from an IMAP server.
        """
    greetDeferred = None
    
    def serverGreeting(self, caps):
        self.serverCapabilities = caps
        if self.greetDeferred is not None:
            d, self.greetDeferred = self.greetDeferred, None
            d.callback(self)
    
    def lineReceived(self, line):
        print "<" + str(line)
        return imap4.IMAP4Client.lineReceived(self, line)

    def sendLine(self, line):
        print ">" + str(line)
        return imap4.IMAP4Client.sendLine(self, line)

Code – QUOTAROOT Implementation

def cbExamineMbox(result, proto):
    """
        Callback invoked when examine command completes.
        
        Retrieve the subject header of every message in the mailbox.
        """
    print "Fetching storage space"
    cmd = "GETQUOTAROOT"
    args =  _prepareMailboxName("INBOX")
    resp = ("QUOTAROOT", "QUOTA")
    d = proto.sendCommand(Command(cmd, args, wantResponse=resp))
    d.addCallback(cbFetch, proto)
    return d

def cbFetch(result, proto):
    """
        Finally, display headers.
        """
    print "Got Quota"
    print result

Output

Fetching storage space
>0005 GETQUOTAROOT INBOX
<* QUOTAROOT "INBOX" ""
<* QUOTA "" (STORAGE 171609 10584342)
<0005 OK Success
Got Quota
([], 'OK Success')

So I am getting the data but the result doesn’t contain it, I am thinking it is because they are untagged responses?

Answer 1

Since the IMAP4 protocol mixes together lots of different kinds of information as “untagged responses”, you probably also need to update some other parts of the parsing code in the IMAP4 client implementation.

Specifically, take a look at twisted.mail.imap4.Command and its finish method. Also look at twisted.mail.imap4.IMAP4Client._extraInfo, which is what is passed as the unusedCallback to Command.finish.

To start, you can check to see if the untagged responses to the QUOTA command are being sent to _extraInfo (and then dropped (well, logged)).

If so, I suspect you want to teach Command to recognize QUOTA and QUOTAROOT untagged responses to the QUOTA command, so that it collects them and sends them as part of the result it fires its Deferred with.

If not, you may need to dig a bit deeper into the logic of Command.finish to see where the data does end up.

You may also want to actually implement the Command.wantResponse feature, which appears to be only partially formed currently (ie, lots of client code tries to send interesting values into Command to initialize that attribute, but as far as I can tell nothing actually uses the value of that attribute).