[OSM-dev] [OSM] Informations about osmarender for Google SoC

Mario fadinlight at gmail.com
Sun Mar 23 14:10:04 GMT 2008

Hi 80n! :)

> JOSM is directed towards editing nodes, ways and relations.  For the 
> Osmarender frontend you want to be editing rules and styles.  Not sure 
> that JOSM helps much with that.

My idea was to integrate this as an independent JOSM plugin only to let 
the final user living with as few different programs as possible. IMHO, 
this could improve the overall usability. There would be no direct 
relation with JOSM code (perhaps, if it's possible, the plugin could 
take the OSM file which JOSM is editing in the same time).

> 1) I'd imagine something that has a test .osm file and a complete rules 
> file as input.  It should then display the rendered test file and 
> provide a way for the user to change the styling of any element 
> (motorway, footway, river, building, etc).  It should then emit a 
> modified rules file.  Once you have a solution that can edit styles, 
> you'd then need to be able to add/remove/edit rules.  This is a 
> different kind of activity from editing styles.

So, if I understood well.. I'm focusing these guidelines, which I'm 
integrating with some ideas of mine:
1) The user can edit overall options (found in 

2) There should be some way to add/remove/edit styles. My idea is to let 
the user select from a list of the real CSS names and/or select from a 
"modified name" (eventually hierarchical.. i.e. "stroke-width" becomes 
"width" under menu "stroke", with some associated help tip)

3) Enter rules easily. This should be something like a "query editor" to 
select "all kind of nodes like.." or "this node" (is there a way to pick 
up a specified node in the original OSM? Sorry I've to study better :)) 
and associate a style to it.

4) There should be a way to pass easily between styles and rules to 
handle issues like "I've created a rule but I forgot to create the 
associated style..." or "This style it's not what I wanted, I must 
change that".

5) Node names or way names (or groups) can be selected through a kind of 
pull down menu which filters the content of the original OSM file.

6) Symbols/areas can be selected by a text/visual selection, which 
contains images extracted from symbol-catalogue.svg (or other collection 
like that). In addition, it should accept custom symbols uploaded by the 

7) I think it could be great to let the user view tips somewhere in the 
program, like what can be found in 
http://wiki.openstreetmap.org/index.php/Osmarender/Tips, or what can be 
found in http://wiki.openstreetmap.org/index.php/Osmarender_Styleguide. 
These tips should be not the "tip-of-the-day", but I imagine something 
more "target-oriented", so they will be viewed only in relevant areas of 
the program. (for example, color tips should be viewed when I'm editing 
a color style, not a width style :)))

8) Something useful could be optionally saving created 
styles/rules/symbols (a sort of internal library).

9) This is a question more than a proposal. I can't understand how are 
"osmarender:" tags are used. Should they be added to the OSM file before 
applying styles and rules?

In this case... it could be great to select single ways/areas directly 
from the preview output.. but I'm starting to be visionary ;) ;)

Please let me know if there is something I haven't understood well.

> It might be worth looking to see what can be done with Inkscape plugins.
> 2) Another approach would be to augment some generated svg with 
> javascript and build a style/rule editing app that runs in a browser.  
> This would probably be a bit more work than using, say, Inkscape, but 
> could be a nice lightweight solution.

Can you please explain better this approach? I'm figuring a "classic" 
web app, with some AJAX to let the browser render any modified SVG file 
the WYSIWYG way, and some javascript (or a Java servlet) to modify 
styles/rules. Is this correct?



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