hmm, the ‘novelty’ i think is having an xtype calculated with values from outside weewx (eg cpu temperature), and the expense of the calculation is not really at issue - though normally they would be light-weight in case they are used often (eg barometer)
architecturally anything external is supposed to brought into weewx via a service and made available via weewx packet. (the *providing* of an xtype is now positioned as a service, but the xtypes themselves are not.) okay, i’ll recast my vitalstats from xtypes_service to data_service and not bypass the packets... > On 28 Dec 2020, at 11:40 am, Tom Keffer <[email protected]> wrote: > > That's a novel use of xtypes, but I'm not sure it's always a good idea. In > this case, I think you'd be better off simply adding the type to the LOOP > packet or archive record. > > The intended purpose of xtypes is to calculate derived variables. It's > entirely possible it could be called many times during a reporting cycle, > depending on the template used. Something involving I/O could be very > expensive. > > Having said that, xtypes also do database accesses, which can also be very > expensive, so my advice is inconsistent. So, not saying never do it, but > think it through. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/29A71619-51B9-41B6-A4AB-14E54482FB56%40gmail.com.
