Wikipedia-Community: Can someone summarize what Wikipedia Kartographer does

Hey! I wanted to nudge someone who already looked into the new mapping feature for Wikipedia “Kartographer” to create a blog post from the point of view of the OSM community.

I think it would be great to use this new feature to increase the cooperation between both projects.


Are you looking for info about how to use the Kartographer extension on e.g. the OSM wiki? Or how to use it on Wikimedia wikis?

I think one of the key things to know about the OSM–Wikimedia integration is that the wikidata key on an OSM feature is what’s used to display geometry on a Wikimedia wiki page (e.g. this wiki page shows this OSM boundary). There’s also a link in the other direction, from a Wikidata item (as OSM relation ID) but this doesn’t get used by Kartographer for displaying on-wiki maps.


Thanks Sam, the extension docs are helpful, thanks!

Here are a few thinks I learned from that and from other conversations. Maybe we can stitch together a full picture here :).

  • The extension can show points and areas from all kinds of sources. But the most important source for OSM is the wikidata-key on a osm object.
    • Off all the methods to pull geometries into Kartographer this is the only one where OSM is involved, right? Or are there indirect methods via SPARQL (…)?
    • This is an indirect relation: The OSM object gets the tag; wikipedia looks directly at the OSM data; no wikidata-to-osm “relation” is needed
    • Do we know how they do this? I suspect they have their own minutely updated DB?
  • A map can have multiple Wikidata IDs (like shown in Help:Extension:Kartographer - MediaWiki)
  • However, I heard that the map cannot handle the case when a Wikidata ID is tagged on multiple OSM objects. If true, I really hope they will fix it, since showing a road in Wikipedia mean, liking to the Wikidata ID of the Road which in turn is added to all road segments.
    • Do we know if this issues will be worked on? Is there a public tracker for issues?
  • It looks like there is no tooling from Kartographer to add the Wikidata ID, so that needs to be looked up manually, right?
  • I wonder, if only wikidata keys or also all the other *:wikidata:* key would work. The docs only reference wikidata, but from an OSM point of view we would want tags like subject:wikidata and such whenever needed… – They link the wikidata wiki page which in turn explains those other tags, so that is fine I guess.

Help:Extension:Kartographer/OSM - MediaWiki outlines how to add a wikidata ID to an OSM object. They suggest adding wikipedia and wikidata tags (no mention of subject:wikidata or any other *:wikidata:* key).
The database is updated daily:

The data should become available for Wikipedia in about 1 day (we are still working on making this quicker)

Help:Extension:Kartographer/OSM - MediaWiki suggests adding the Wikidata ID to a (new) route relation covering all road segments.
Issues are tracked here: Maps (Kartographer) · Workboard

Quite close to heresy, IMO

What’s wrong with making a relation that contains all parts of a road? I do that quite often!

I think it makes sense that a Wikidata ID shouldn’t be on more than one object — it’s supposed to represent a single entity, and if that entity can’t be modeled in OSM as a single feature then it seems reasonable that all of its features should be contained together in a relation (although a boundary way is also pretty common for this too, e.g. for a school or whatever that contains many buildilngs).

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I don’t follow this reasoning, a wikidata id is meant to represent a single entity in wikidata and if we can’t represent this with a single object in OpenStreetMap because of reasons, there is nothing wrong with having the wikidata id on several objects. We can also create an additional object to collect the parts, but it is not the only way that makes sense


I don’t mean from the Wikidata side: I think that it makes more sense on OSM for a single thing to be united by a relation, if all the parts of it are of the same thing. A road for example, should definitely be a relation — don’t you agree?

It’s definitely not the only way that makes sense, you’re right, but I don’t think it’s a wrong way at all. It also makes things easier for people using the data elsewhere, so that’s a bonus.

I am not sure what a single thing is, e.g. a road, what is the criterion? Does it have to be linear or can there be bifurcations? Is it only the name that counts? Address within the same municipality?
If we make a relation to have just one time the wikidata id than it seems the reasoning is outsourced to wikidata and following their rules and concepts of what is a thing.