Is this sufficient as API to read mappings?

[JeroenDeDauw]

@despens @lozanaross @paulduchesne We have added a REST API endpoint to retrieve the mappings for an entity at rest.php/wikibase-rdf/v0/mappings/Q1. This API returns the mappings in a JSON format. You can use the same API to write mappings to an entity via the same JSON format. So this can be used to export and import mappings.

Question: do we need any additional APIs in this extension to export mapping information? And is the JSON format fine, or should it be changed somehow?

Browser view on the read API:

JSON returned by the read API:

{
    "mappings":[
        {
            "predicate":"owl:sameAs",
            "object":"http://www.w3.org/2000/01/rdf-schema#subClassOf"
        },
        {
            "predicate":"skos:exactMatch",
            "object":"http://www.example.com/foo"
        },
        {
            "predicate":"rdfs:subClassOf",
            "object":"http://www.example.com/bar"
        },
        {
            "predicate":"rdfs:subPropertyOf",
            "object":"http://www.example.com/baz"
        }
    ]
}

[paulduchesne]

This syntax looks correct to me, my only question is whether there would be an option for this API to pull all mappings from across the entire wikibase, eg if you do not know the corresponding Q/P number but want to pull which Wikibase entity corresponds with a certain object. It would be far more convenient to pull all mappings and filter, rather than loop through all entities.

[JeroenDeDauw]

Does this API need to be something that everyone can access? Or could it be restricted to wiki admins?

[paulduchesne]

Read access should ideally be open to anyone, but we would want some authentication on the ability to write mappings, otherwise there would be a strong chance of vandalism.

[malberts]

What additional data is needed in the response when retrieving all mappings at once?

Is something like this enough where we associate the entity Id with its mappings?

{
  "mappings": {
    "Q1": [
      {
        "predicate": "foo:Bar",
        "object": "http://example.com#Bar"
      },
      {
        "predicate": "foo:Baz",
        "object": "http://example.com#Baz"
      }
    ],
    "P2": [
      {
        "predicate": "foo:Bar",
        "object": "http://example.com#Bar"
      },
      {
        "predicate": "foo:Foo",
        "object": "http://example.com#foo"
      }
    ]
  }
}

[paulduchesne]

I believe this would be sufficient for what we had in mind. Out of curiosity will the creation and/or modification timestamps for these mapping edits be available anywhere? I assume you could access through the "history" section of the wikipage, but would they be accessible problematically (eg through Special:EntityData)? I don't think this would be terribly important, but good to know just in case a use case did arise.

[JeroenDeDauw]

Specil:EntityData will give you access to the modification date of item or property.

<schema:dateModified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2022-07-05T09:37:21Z</schema:dateModified>

You can also get at that modification time via various MediaWiki APIs. This is however looking at the entity as a whole, not just the mappings. If a use case arises where the mapping modification time is needed, and it can't be served by existing APIs, that could always be added as a feature to the extension then. (Following the https://en.wikipedia.org/wiki/You_aren%27t_gonna_need_it principle.)