[Twisted-Python] attribute error when I am trying to make one factory to send data to another

[Pantelis Theodosiou]

On Tue, Apr 28, 2015 at 6:46 PM, Pantelis Theodosiou <ypercube at gmail.com>
wrote:

> No, I don't think that would work.
>
> You would need something like changing these lines:
>
>         reactor.listenTCP(8000, EchoFactory(self))  # for sender
>         reactor.listenTCP(8001, MultiEchoFactory(self))  # for receiver
>
> to:
>
>         self.echofactory = EchoFactory(self)
>         self.multiechofactory = MultiEchoFactory(self)
>         reactor.listenTCP(8000, self.echofactory)  # for sender
>         reactor.listenTCP(8001, self.multiechofactory)  # for receiver
>
> so, your "app" object (which is just a normal Python object) knows the
> other two objects (the instances of the 2 factories).
>
> Then, your calls:
>
>         if sendermessage:
>             self.transport.write(data)
>             #this line here is the trouble maker that caused the error
>             MultiEcho().dataReceived(sendermessage)
>
> could be written:
>
>         if sendermessage:
>             self.transport.write(data)
>
>             self.app.multiechofactory.dataReceived(sendermessage)
>


Oh, I messed it up. The first part is good but the factories do not have
dataReceived methods.

It would have to be - depending on what you want to do - say, you want to
echo to all echoers:

        if sendermessage:
            self.transport.write(data)

            for echoer in self.app.multiechofactory.echoers:
                echoer.dataReceived(sendermessage)

or:

        if sendermessage:
            self.transport.write(data)

            self.app.multiechofactory.echo_them_all()

and define the echo_them_all() method in the MultiEchoFactory() class.



>
> On Tue, Apr 28, 2015 at 6:28 PM, Jessica Tsui <jesadjust at gmail.com> wrote:
>
>> Hi Daniel,
>>
>>   Thank you so much for your suggestion. I am quite new to python and
>> twisted so I am not very certain about how to make it work well. Does that
>> mean if I change the dataReceived by adding a line to instantiate the
>> MultiEchoFactory like this, it will work?
>>
>> def dataReceived(self, data):
>>     "As soon as any data is received, write it back."
>>     handlesendermessage = self.factory.app.handle_message(data)
>>
>>     if handlesendermessage:
>>         self.transport.write(data)
>>         MultiEchoFactory()
>>         MultiEcho().dataReceived(data)
>>
>>
>> 2015-04-29 0:33 GMT+08:00 Louis D. Burr <ldanielburr at me.com>:
>>
>>> Hi Jessica,
>>>
>>> On Apr 28, 2015, at 10:14 AM, Jessica Tsui <jesadjust at gmail.com> wrote:
>>>
>>> SNIP
>>>
>>>  exceptions.AttributeError: MultiEcho instance has no attribute ‘factory'
>>>
>>> SNIP
>>>
>>> MultiEcho().dataReceived(sendermessage)
>>>
>>> Here you create an instance of the protocol directly, i.e., without
>>> having instantiated a MutilEchoFactory.  The factory’s buildProtocol method
>>> is what assigns the factory instance as a member of the protocol
>>> (self.factory), and since you didn’t create the protocol via a factory, you
>>> have no factory attribute on your protocol instance.
>>>
>>> There are a number of ways to fix this, but generally speaking, you need
>>> to provide a way for your factories and their protocols to be aware of each
>>> other.
>>>
>>> Hope this helps,
>>>
>>> Daniel
>>> --
>>> L. Daniel Burr
>>> ldanielburr at me.com
>>> (312) 656-8387
>>>
>>>
>>> _______________________________________________
>>> Twisted-Python mailing list
>>> Twisted-Python at twistedmatrix.com
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>>>
>>>
>>
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>>
>
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