Start of task breakdown:

• Document prefetching-term-lookup-callback in entitytypes.md
• Move Item and Property prefetching-term-lookup-callback service wiring from SingleEntitySourceServices into WikibaseRepo.entitytypes.php for items and properties
• Implement a PrefetchingTermLookup for federated properties
  • ONLY labels to begin with (throw exceptions for aliases and descriptions)
• Wire PrefetchingTermLookup into prefetching-term-lookup-callback for federated properties

Still to breakdown:

We still need to either alter the current EntityIdLabelFormatter for properties (currently at LabelsProviderEntityIdHtmlLinkFormatter)
OR we need to implement our own EntityIdLabelFormatter that does less stuff and override in the federated property wiring using entity-id-html-link-formatter-callback ( in WikibaseRepo.FederatedProperties.entitytypes.php)

We will schedule a further breakdown to look at the last points
I will write the tickets for the first 4 for the morning!

Tasks from the first breakdown are:

• T249795: Document prefetching-term-lookup-callback in entitytypes.md
• T249796: Move Item and Property prefetching-term-lookup-callback service wiring into WikibaseRepo.entitytypes.php
• T249797: Implement a PrefetchingTermLookup for federated properties
• T249799: Wire PrefetchingTermLookup and EntityIdLabelFormatter into prefetching-term-lookup-callback for federated properties

Another thing that came out of the task creak down was a desire to know what we want to do in the situation with deleted properties.

@Addshore from mattermost

@Samantha Alipio we have some questions about https://phabricator.wikimedia.org/T246606
mainly about what to do when properties are deleted on wikidata right now, what would be the desired outcome (a BDD would be good)
within default wikibase this behaviour is explicitly defined which is display "deleted property" in the same way we see now on the test system.
IT would however be a bit easier to not do that for now (we can always do it later), and instead just show the PropertyID
but ultimately your decision

Regarding the the second BDD and if it is working or not as expected currently...

After a bit of investigation the following seems to be true:

so it leads back to WikibaseValueFormatterBuilders::newEntityIdFormatter

which does newLabelsProviderEntityIdHtmlLinkFormatter

which then in WikbiaseRepo does, new FormatterLabelDescriptionLookupFactory( $this->getTermLookup() ),

figures out where the link plays into that

So, it is the LabelsProviderEntityIdHtmlLinkFormatter that is created in WikibaseValueFormatterBuilders::newLabelsProviderEntityIdHtmlLinkFormatter

So, it should be fixed when we do the story that is in the current sprint

specifically it will be fixed when https://phabricator.wikimedia.org/T251242 is done and merged

^^ @Samantha Alipio ^^ not sure how you want to deal with this fun fact