[OSM-talk] Suggestion: fallback tag

John Smith deltafoxtrot256 at gmail.com
Thu Dec 17 13:00:51 GMT 2009


2009/12/17 Shalabh <shalabh.w at gmail.com>:
> On Thu, Dec 17, 2009 at 6:19 PM, Steve Bennett <stevagewp at gmail.com> wrote:
>>
>> Hi all,
>>   As we all know, you don't "tag for the renderer". However, you want your
>> map data to render nicely now, and you want correct map data in the long
>> term.
>>
>> Suggestion: introduce a "fallback" tag.
>>
>> For example, around my city there are little "reserves" - patches of grass
>> reserved by the government for future development such as freeways or train
>> lines. They often get tagged "leisure=park", but say I want to start tagging
>> them "landuse=reserve" instead. Suddenly, instead of being green on mapnik,
>> it will be white again - unrecognised tag.
>>
>> Solution: tag it like this:
>> landuse=reserve
>> fallback:leisure=park
>>
>> That's pretty simple logic to explain to any renderer or editor, and it
>> gives people a way to avoid the temptation of "tagging for the renderer",
>> and allows them to tag for the future instead.
>>
>> What do people think? (No comments on how to tag land reserves, it's just
>> an example...)
>>
>> (This case is slightly complicated by the fact that the two tags - landuse
>> and leisure - are different. Perhaps a more explicit
>> fallback:landuse=leisure:park would be clearer.)
>>
>> Steve
>>
>>
>> _______________________________________________
>> talk mailing list
>> talk at openstreetmap.org
>> http://lists.openstreetmap.org/listinfo/talk
>>
> 1. And what if even the 'fallback tag' is not rendered by the renderer?
> 2. Some things may have just no fallback e.g. Mountain passes are not
> rendered by most renderers. What would be the fallback tag in such a case.
>
> In my opinion, this will only confuse the mappers more when they tag a POI.
> A few days down the line, we would have many more questions on what should
> be the fallback of what and why?
>
> I would think a better idea is to have atleast one renderer and the main OSM
> map to render a superset of all tags.

+1

This should be in the rendering logic, not the map data, otherwise
it's no better than tagging things with the icons to use for POIs etc.




More information about the talk mailing list