[OSM-dev] relations and "dependancies"

[Frederik Ramm]

Hi,

On 04/14/2011 10:12 AM, the.promenader at gmail.com wrote:
> I made another suggestion here -
> http://www.openstreetmap.org/user/ThePromenader/diary/13574 - that'll
> be all for this week ; ). Thanks for any input.

I think you're mixing up the data model, the editing, the rendering, and 
the geocoding. All are relatively independent of each other. In your 
diary post you suggest a special "dependency" concept so make it easier 
to find objects or to render them.

But you don't need something new for this. You can use relations for 
this. As a newbie you may be confused about all the purposes relations 
are used for, but that's just because our editing tools are so primitive 
that they actually show the relations to the user, whereas at least an 
entry-level editor could easily hide them (and present "areas", 
"dependencies", "turn restrictions" to the user instead of relations, 
relations and relations).

In your post you suggest to place extra address nodes inside buildings 
and link them to the building with a relation. This is not something we 
usually do; we usually tag the building itself with an address - no 
extra node required, and certainly no relation.

You also mention that objects located on an addressable polygon could be 
found by means of a dependency relation, but if the geocoder or search 
engine wants, they can be found even today without any extra relations. 
(Just as the geocoder knows that a certain place is in a certain country 
- just from the geometry.)

Part of your suggested "property dependency" situation is also covered 
by the existing "site" relation type.

Regarding your suggestions for rendering; again you are thinking of a 
graphics program that allows you to "bring to front" something, but in 
our world it is the renderer that decides if something is rendered on 
top or below something else - not the mapper. The mapper makes an effort 
to describe reality, and the renderer then picks some parts of reality 
to show on the map.

Bye
Frederik