[OSM-talk] Map features page on wiki

[Jochen Topf]

On Sa, Okt 01, 2016 at 02:36:58 +0200, Tobias Knerr wrote:
> On 21.09.2016 01:33, Matthijs Melissen wrote:
> > I added it to the infobox as osmcarto-rendering.
> > 
> > It is currently only used in the supermarket page:
> > https://wiki.openstreetmap.org/wiki/Tag:shop%3Dsupermarket
> 
> Maybe I'm a bit late to the party, but I don't feel it's great to give
> special treatment to Mapnik in the infobox, and there is not enough room for
> presenting all the renderers there.
> 
> While placing the icon in the infobox is probably the easiest way to make it
> available to Taginfo, we shouldn't forget that it also determines how
> renderer support is presented on the tag pages. And in that regard, I find
> it's a less than ideal solution.
> 
> Quite some time ago, someone suggested a "Rendering" section on tag pages,
> with example images for all (or at least a wider selection of) renderers
> supporting the feature. This wouldn't be limited to icons, either, but would
> also work for area styles, for example. I would clearly prefer a
> presentation along those lines, as it would represent the diversity of OSM
> rendering in a way that a Mapnik icon does not.
> 
> Of course this leaves the issue how to implement something along these lines
> while still allowing Taginfo to access the content. I don't pretend I have a
> solution, but could this information be integrated into the Taginfo projects
> JSON somehow? If I remember correctly, there is already the possibility to
> add icon urls.

Our "main map", the one with what we used to call "mapnik style" and now
sometimes call "osmcarto style" or so is somewhat special. It is the
only "general" style that we have that explicitly tries to show as many
features as possible. And there is the precedence of showing this style
(and this style only) in the tables on the Map Features page and in
other places on the wiki.

So I think it is not totally wrong to argue that this style is special
and is the only style we present in the Info Box and/or Map Features
page. But I also agree with your argument that it would make sense to
show more styles. 

For taginfo it is easiest to get the information out of the Info Box. It
is also easy to get the info out of the projects json files it already
collects. But if we agreed on some different format, that is also
something taginfo could support. So which mechanism we choose should not
depend too much on what's convenient for taginfo. Taginfo is software
that we can change and the effort involved is likely to be small. The
effort of maintaining all those icons is much larger. Ideally it is done
somewhere, where lots of people can help.

At the hack day at SOTM Matthijs and I threw around some ideas on how to
best get those icons into taginfo and back out and had the idea that it
doesn't make much sense importing all those icons manually into the wiki
when they are already in a git repository somewhere. We thought about
including the URL of the icon in the info box. But now with your
proposal, maybe it makes more sense to leave the wiki out of it
completely and just collect the icons all into some format (basically a
map legend) and let taginfo read it from there (and then maybe export it
into the wiki through the taglists feature). As you mention, we already
have a format that would support most of this (the taginfo projects json
files).

On the other hand all of this leads down the rathole of automatically
generating a map legend. It should be possible to create the list of
icons more or less automatically, but nobody has ever tried actually
implementing this. We can not delay introducing taglists because we are
waiting for somebody to implement legends, because this might never
happen. Yes, there are better ways of handling all this than copying
icons into the wiki manually and all this. But we are trying to solve
one problem here (the overcomplex and huge tag lists we manually
create) and we can't solve all the problems at once, otherwise we will
never get anywhere. So I think the way forwards has to be the simplest
thing we can do so that we can actually finish the current task and
then, after we have done one thing, we can think of tackling the next
one.

All of this brings me back to the first proposal: Just put the icons
into the info box (we don't even have to display them in the info box,
the template that creates the info box is just a convenient place to put
this data). Then taginfo gets the data from there and puts them into the
list. This is the short-term solution that would allow us to have the
same Map Features page we already have, with a hugely reduced (but not
totally removed) maintainance burden. Long-term somebody has to
implement map legends which taginfo can then understand.

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.jochentopf.com/  +49-351-31778688