[Twisted-Python] ftpclient connection lost callback

[exarkun at twistedmatrix.com]

On 06:48 pm, peter at peterryan.net wrote:
>Thanks.
>
>So is the idiomatic approach for this with something like the FTPClient 
>to
>subclass it and override connectionLost? FTPClientBasic clears up 
>queued
>commands when this happens (which I assume I still want it to do).

Is it idiomatic?  I don't know.  It accomplishes your goal.  If you 
like, propose a better API (file a ticket, attach a patch, etc:

http://twistedmatrix.com/trac/wiki/ContributingToTwistedLabs#CodeContributions

)

Jean-Paul
>To me it seems a little overbearing to have to subclass the ftpclient 
>just
>to get a tcp connection lost event (which seem like an event most users
>would be interested in).
>
>
>
>
>
>
>On Thu, Sep 5, 2013 at 1:35 PM, <exarkun at twistedmatrix.com> wrote:
>>On 05:49 pm, peter at peterryan.net wrote:
>>>I am writing a simple ftp client which I am trying to dispose of. 
>>>Right
>>>now
>>>I send a quit command:
>>>
>>>(the ftp_client reference is a FTPClient built with a ClientCreator)
>>>
>>>deferred = ftp_client.quit()
>>>
>>>And I register a callback:
>>>
>>>def quitSent(response):
>>>   print "quit acknowledged...connected?", 
>>>ftp_client.transport.connected
>>>
>>>deferred.addCallback(quitSent)
>>>
>>>If I invoke the above the connection is printed as connected.
>>
>>There is no documented `connected` attribute of transports.  So who 
>>knows
>>what this is telling you. :)
>>
>>However, the way you learn when a protocol's transport has 
>>disconnected is
>>to implement the `connectionLost` method on the protocol.  It is 
>>called
>>when the transport disconnects.
>>
>>Jean-Paul
>>
>>  However if I schedule a callback to check the status later:
>>>
>>>def status():
>>>   print "quit acknowledged...connected?", 
>>>ftp_client.transport.connected
>>>
>>>reactor.callLater(1, self.status)
>>>
>>>If I schedule a callback for a second later the transport is not
>>>connected.
>>>I've searched quite a bit but I cannot determine a way to register a
>>>callback for when the TCP transport is actually disconnected. Can 
>>>anyone
>>>offer some insight? I'd like to know explicitly when the client is 
>>>closed.
>>>
>>>Thanks,
>>>
>>>Peter
>>
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