[OSM-dev] Advice sought on polygon-with-hole drawing

Igor Brejc igor.brejc at gmail.com
Sat Mar 15 05:48:46 GMT 2008


Jon Burgess wrote:
> >From a pure design perspective the cleanest approach would be (IMO) to
> have the tags only on the relation. Otherwise there is always the
> possibility for ambiguity in cases where the tags on the outer ways
> differ. Yes this is an error, but one which is bound to occur
> occasionally. It also enables other use cases like re-using a way along
> a border between 2 country polygons.

But then we'll end up with non-tagged ways. From the OSM data design 
perspective its not going to be very practical for someone to determine 
whether the way is not tagged because it belongs to a certain relation 
or because it was forgotten. And don't forget that a relation could be 
anything. not just "polygon-with-hole", so you would have to understand 
the semantics of all types of relations.
Also, since AFAIK osmxapi currently does not support relations, 
renderers which use data collected from it would have to ignore these 
untagged ways completely.

Igor

-- 
http://igorbrejc.net





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