On Mon, Oct 18, 2010 at 8:50 PM, Ian Dees <[email protected]> wrote: > On Mon, Oct 18, 2010 at 7:43 PM, Nathan Edgars II <[email protected]> > wrote: >> >> On Mon, Oct 18, 2010 at 8:38 PM, Ian Dees <[email protected]> wrote: >> > On Mon, Oct 18, 2010 at 7:32 PM, Nathan Edgars II <[email protected]> >> > wrote: >> >> >> >> On Mon, Oct 18, 2010 at 8:15 PM, Ian Dees <[email protected]> wrote: >> >> > Ways and relations are equally easy to "break" >> >> >> >> Nope. They're not, because relation membership is not a tag on the >> >> way. >> > >> > Yes, they are, because a relation membership and new way (with new tags >> > and >> > node refs) are both completely separate new entities that need to be >> > uploaded. If an editor can reliably do it with a new way then it can >> > also >> > reliably do it with a new relation member. >> >> When a way is downloaded from the API, its tags are all downloaded, >> but a separate API query has to be sent to get any referring >> relations. > > Presumably if you are splitting a way you will have already downloaded at > least the one relation way member that you want to split.
But you haven't necessarily downloaded the relation itself. On the other hand, it's impossible to download a way without its tags. >> >> >> >> A way is always uploaded with its tags, >> > >> > Yes, but the new (split) way is not necessarily always uploaded. >> >> Relations are uploaded after new ways to avoid precondition failures. >> Thus it's much more likely that a connection will fail between the way >> and the relation than between two ways. I've seen Potlatch take >> several tries to upload a large relation, which compounds the possible >> problem. It's also obvious from the map when a portion of a way is >> accidentally deleted, but even if relations were used to render >> shields an error would not always be obvious. > > If the renderer uses route relations to render roads, why would errors be > any less obvious than when ways were used? > If the new (split) way is not uploaded, it shows up as a gap in the road. That's going to be really obvious. >> >> I have seen these problems in my work on repairing relations. Do you >> have any such experience? > > I have been offering suggestions to solve the route problems in the original > thread. Do you have any such suggestions? I have no problem with the solution of using relations, but ref tags on ways should remain as a backup. _______________________________________________ Talk-us mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-us
