[Tagging] A first step towards bringing the wiki and tool support closer together

[Jochen Topf]

On Wed, Dec 09, 2009 at 03:06:53AM +1100, Steve Bennett wrote:
> After a few exciting hours learning XSLT 2.0, I've created this:
> 
> http://wiki.openstreetmap.org/wiki/User_talk:Stevage/Mapnik-support
> 
> In summary, it provides a simple function: "Does Mapnik currently make
> reference to <tag>=<value> in its oms.xml file?"  That is,
> {{Mapnik-support|railway|tram}} returns "yes",
> {{Mapnik-support|sport|cricket}} returns "no".

Interesting idea. There is definitely some potential there.

First comment though: Please, please start making a distinction between the
rendering software (Mapnik) and the style file is uses and the map it creates,
respectively. This is already problematic. It should not be called
"Mapnik-support", but something like "Default OSM Map-support". We should
come up with nice name for the default map.

Second comment: As always, its not that easy. You can't just read osm.xml.
At least you have to take the osm2pgsql config into account. Also you probably
want to differentiate between nodes, ways (lines vs. polygons?) and relations.
But its a start. I wouldn't want to see this on the Map Features immediately.
That might come at some later point, but if its on an extra page with a large
disclaimer, that its preliminary, doesn't show all tags, etc. thats fine.
People can check it, improve it and get some experience about its usefulness.

Just an idea: If you really want to check what the renderer renders and what
not, how about creating a osm test file with all the different tags ins there,
send it through the renderer and check whether the bitmap is empty. If it
contains something in the right spot, you know the tag is supported. This is
totally renderer and style agnostic reasonably easy to automate.

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298