On 05/07/19 19:57, Mariusz wrote:
On 05.07.2019 07:05, Joseph Eisenberg wrote:
I've removed this statement from the page because it leads to
ambiguous data and directly contradicts the One feature per one
element rule
[Examples of bad situations:] "An area object representing a
single-use building with a point object inside it. Move the tags to
the area object and delete the point."
This is common and widly accepted practice. Don't try to change
mappers behaviour by editing wiki.
Also, there is no contradiction. From wiki: "It means one
on-the-ground real world feature should be mapped with only one OSM
element. " That it - no multiple osm objects for one real world feature.
It is fine to map multiple real objects with one osm element,
especially if you don't have enough data to map them seperately.
I have done both - mapped a shop on the building way and in a different
place, as a node inside a building way.
The advantages of having the shop as a node inside a building way .. if
the shop moves it is much easier to move the node and the history is
retained. I think I prefer the shop as a node method in hind sight.
Much easier to maintain.
If the same feature is tagged with building=* and another feature like
shop=* or office=*, it's ambiguous whether other tags like name=*
represent the building itself or the other feature.
Nothing new, this problem already existed with roads and bridges and
was fixed by putting bridge name into bridge:name tag.
While it's common to tag single-use buildings in this way, it isn't
the best practice, because of this ambiguity. Users should not be
encouraged to delete all single node objects within buildings without
carefully considering each of the tags.
That's true. POI and building may have more identical tags, for
example "start_date" or "operator".
Moreover, you recently edited many times
https://wiki.openstreetmap.org/wiki/One_feature,_one_OSM_element and
some newly introduced things are controversial:
*"Ideally, every OSM element or object should be tagged with only one
main feature tag, to represent a single on-the-ground feature."
I've never heard of such rule. It doesn't seemed to be correct. It is
against KISS principle and it is not how mappers map.
For example, there is nothing wrong in placing tags
"landuse=industrial + barrier=fence" on one osm way. Doing it as 2
ways would even give you a warning in JOSM (ways in the same position).
Some possible issues with that?
The fence is usually inside the boundaries of the land use.
The fence will have at least gates.
The fence may not be of a consistent height/construction ..
*"For example, use the feature leisure=picnic_site with the property
tag drinking_water=yes, instead of using the separate feature tag
amenity=drinking_water on the same node or area."
This example is a bad idea and mappers shouldn't be encouraged to do
so. amenity=drinking_water is far more popular tag and replacing it
with drinking_water=yes may hurt data consumers.
I don't think it is an issue of replacing it. But where the location of
the drinking water is unknown?
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