[OSM-talk] Area tags in Overpass API

[Dave Sutter]

I like GeoJSON since it is JSON, which I find convenient, and it is a
standard. All the same, most vector rendering on clients is done using
the path formalism which doesn't distinguish between areas and lines
outside of applying the style to the geometry. It is kind of a shame
to have to worry about this just for the transport mechanism. But I
guess there is not really much of a choice if you want to support this
standard of one of many other geo standards. :-(

Dave

On Fri, Mar 22, 2013 at 3:38 PM, Roland Olbricht <roland.olbricht at gmx.de> wrote:
> Hi all,
>
>> I'm also curious about the motivation for considering only a strictly
>> limited subset of the areas in the database in the first place.
>> Presumably this is because maintaining a large number of areas would be
>> detrimental to performance?
>
> First of all, thank you for taking it here. This allows for a in-depth
> discussion.
>
> The performance was the initial reason to use a whitelist at all. However, the
> performance has since been a lot improved, and it could be, with some hours of
> programming effort, improved even more.
>
> The reason to choose objects with name was that all use cases so far have been
> variations of the question "Where am I?". And without a name or other
> distinctive tag value, the area has been considered to be of little use.
>
> The deeper reason is that I would like in general to let Overpass API be tag
> agnostic. The areas are one of the few places where I haven't found a way to
> get areas without tag evaluation.
>
> And there is even a future driven reason to encourage feedback: In the long
> term, Overpass API will produce GeoJSON to allow vector rendering. The main
> roadblocker for this is the distinction between linestrings and polygons. I
> assume that an established list of tags that designate areas are the best way
> to achieve this with long-term stable semantics.
>
> Cheers,
>
> Roland
>
>
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