In a disucssion with @Arian_Bozorg as this has potential effects on the WDQS, it is important that T336054: [ES-M2]: Confirm new the EntitySchema data type's queryability is done before any of this is merged to production, as such we will associate it to this task as a subtask.

Task Breakdown Notes:

• In the data type registration for EntitySchema we can add a key for a rdf-builder-factory-callback and create a class to return a similar representation to https://gerrit.wikimedia.org/g/mediawiki/extensions/Wikibase/+/master/repo/includes/Rdf/Values/CommonsMediaRdfBuilder.php
• Return from this callback the full canonical URI for an EntitySchema

Change 928001 had a related patch set uploaded (by Hoo man; author: Hoo man):

[mediawiki/extensions/EntitySchema@master] Add EntitySchema URI to RDF output

https://gerrit.wikimedia.org/r/928001

Change 928001 abandoned by Hoo man:

[mediawiki/extensions/EntitySchema@master] Add EntitySchema URI to RDF output

Reason:

doh

https://gerrit.wikimedia.org/r/928001

Change 928000 had a related patch set uploaded (by Hoo man; author: Hoo man):

[mediawiki/extensions/EntitySchema@master] Add EntitySchema URI to RDF output

https://gerrit.wikimedia.org/r/928000

@hoo I tested this but some work (hopefully trivial) is required before the WDQS munger is able to interpret these URIs properly in the RDF output (created a subtask to track this work).

In T336056#8910743, @dcausse wrote:

@hoo I tested this but some work (hopefully trivial) is required before the WDQS munger is able to interpret these URIs properly in the RDF output (created a subtask to track this work).

Please ignore, this was me not setting the test correctly, these URIs should not cause any issues, I added some tests in the codebase.

Change 928000 merged by jenkins-bot:

[mediawiki/extensions/EntitySchema@master] Add EntitySchema URI to RDF output

https://gerrit.wikimedia.org/r/928000

This can be verified as working correctly on beta wikidata.

The Property P253078 has a Statement with linking to an EntitySchema semantic Entity.
The RDF-data for P253078 can be accessed via Special:EntityData: https://wikidata.beta.wmflabs.org/wiki/Special:EntityData/P253078.ttl

There one finds the section about that Statement. Notice the prefix in wd:E1:

s:P253078-a216dc88-4f3b-d2b3-c08b-d06bf7d15179 a wikibase:Statement,
		wikibase:BestRank ;
	wikibase:rank wikibase:NormalRank ;
	ps:P253078 wd:E1 .

That refers to

@prefix wd: <https://wikidata.beta.wmflabs.org/entity/> .