[OSM-dev] API 0.7+: Split node concept?

Frank Steggink steggink at steggink.org
Tue Oct 12 22:11:35 BST 2010

On 10-10-12 10:41 PM, Matthias Julius wrote
> Maybe less ugly would be to have nodes just contain lat and lon and
> introduce new point elements that need to reference a node.
> That would also make it easier to put two different objects at the same
> spot (like a mail box on a lamp post) as added benefit.
+1 for such a separation of responsibilities of nodes and point features.
IMO this would also be beneficial for line and polygon features. 
Features should be cleanly separated from their geometries, which is not 
currently the case. This can be done in such a way that the topological 
integrity remains intact.

As proposed by Matthias, one point feature would reference one node. A 
linestring feature would reference one or more consecutive ways, whereas 
a polygon feature would reference one or more closed sets of ways (also 
called 'rings', one exterior, zero or more interior rings). Maybe 
geometric aggregates (set of disjoint geometries) should be allowed as 
well, either homogeneous (multipoint, multilinestring, multipolygon), or 
heterogeneious (multigeometry). That would be possible with this model 
as well.

If this were to happen, it would also be easier to manage things like 
bridges and (simple) routes. Now it is too often necessary to chop up 
ways, use relations, etc., so that ways end up with a whole bunch of 
tags. I find situations like this difficult to manage.

Probably there has already been plenty of discussion about this in the 
past, but I think it would be worthwhile to discuss this further for a 
future API version :)


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