On Thu, Jul 30, 2009 at 3:01 AM, Glyph Lefkowitz<gl...@twistedmatrix.com> wrote: > Presumably the future plan is to have IPositioningProvider that receives > data from something other than NMEA, as well? (Other GPS protocols, > whatever cell phones give you for triangulation, skyhook, etc.)
Yep, that's the idea. > A minor nit here, would you put the interfaces in their own module, > 'twisted.position.ipositioning'? Done in new revision. > There are multiple layers here. Let's have an object for each layer. The > NMEA protocol parser object should send NMEA-sentence events to a sentence > receiver object, then there should be an implementation of the > sentence-receiver interface which generates positioning events and sends > them on to a positioning-receiver interface. Agreed. That's what I'm doing now -- see nmea.NMEASentence. This will perpetuate through the rest of the code. > I've attached a sketch, but it elides certain details like set-up and > tear-down; there should be methods which allow users to tell when sentences > and positions start and stop arriving. The gist would be to have a > connectionMade and connectionLost invoke startReceivingNMEA, > stopReceivingNMEA, which in turn would invoke startReceivingPositions, and > stopReceivingPositions. Extremely helpful, thank you. I think I was confused because LineReceivers, which make sense for NMEA since it's a line based text protocol delimited by '\r\n', is-a protocol but is called "receiver", so I figured my receiver should be a LineReceiver, and not that it should be delegated from by a LineReceiver subclass. To be honest, it still looks kind of wonky that a LineReceiver (well, a subclass) delegates to a receiver, but maybe that's just my inexperience showing :-) What exactly would those startReceivingNMEA/stopReceivingNMEA/startReceivingPositions/stopReceivingPositions do? I don't think there's any setup to be done, so I guess that I should just have an instance attribute on the appropriate class that is set by startFoo/stopFoo. If it's false, callbacks don't fire. Right? > There should also be a factory which nicely hooks everything together and > takes only a factory for your IPositioningProvider, so that users can > quickly get started with a positioning provider. Okay, I'll do that as soon as people have reviewed the changes suggested in your last mail, so that I know I got it right :-) (also, sorry for the late reply -- the mailing list decided to make me wait three hours before I could see my own mail, let alone yours) Thanks for your input Laurens _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
