Make the deep-link fragment the bare Subject ID

Per review, the Data tab URL fragment is the bare Subject id (`#sEpfwJLAtndCccC`), like Wikibase's
`#P123`, not the row's DOM id. The fragment never needed to equal a DOM id — the mount handler does the
expand/scroll/highlight itself and the highlight is class-based — so fragment and DOM id decouple. The
row DOM id stays `ext-neowiki-subject-row-{id}` as an internal rendering detail.

- Dereference endpoint (`data-tab`): the Location fragment is now `#{subjectId}`.
- Data tab: `applyHash` reads the fragment through a bare-id parser (`subjectIdFromHash`); manual expand
  writes `#{subjectId}` via `history.replaceState`.
- Removed `SubjectRowAnchor` and its literal-pin test: with the fragment being the id itself there is no
  prefix scheme to keep in lockstep across languages. The handler appends `'#' . $subjectId`; a handler
  test asserts the Location ends with the bare id, and a vitest asserts the parser accepts exactly
  subject-id-shaped fragments (and rejects the old long form — no legacy acceptance).
- The dereference tests pin a `page` baseline in setUp so the Accept-negotiation tests are independent
  of any ambient $wgNeoWikiSubjectDereferenceTarget; the now-redundant explicit page-target test is
  dropped.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: JeroenDeDauw

docs/rdf/rdf-export.md

@@ -108,7 +108,7 @@ TriG wins when both RDF types are acceptable; the RDF redirects use the native p
 on a page the caller may not read returns one indistinguishable `404`; a malformed id `400`.
 
 The HTML target is the Subject's hosting page by default, or that page's Data tab (`?action=subjects`) opened on the
-Subject's row when `$wgNeoWikiSubjectDereferenceTarget` is `data-tab`.
+Subject's row (`#{subjectId}`) when `$wgNeoWikiSubjectDereferenceTarget` is `data-tab`.
 
 The negotiator is always reachable at the REST path, which needs no server configuration:
 

resources/ext.neowiki/src/components/SubjectsManager/SubjectsManagerPage.vue

@@ -467,7 +467,7 @@ import { useSubjectStore } from '@/stores/SubjectStore.ts';
 import { useSchemaStore } from '@/stores/SchemaStore.ts';
 import { useSubjectPermissions } from '@/composables/useSubjectPermissions.ts';
 import { useSubjectDrag } from '@/composables/useSubjectDrag.ts';
-import { subjectRowDomId, subjectIdFromRowDomId } from '@/presentation/subjectRowDomId.ts';
+import { subjectRowDomId, subjectIdFromHash } from '@/presentation/subjectRowDomId.ts';
 import { Subject } from '@/domain/Subject';
 import { Schema } from '@/domain/Schema';
 import { SubjectId } from '@/domain/SubjectId';
@@ -663,10 +663,11 @@ function toggleExpanded( id: string ): void {
 		next.delete( id );
 	} else {
 		next.add( id );
-		// Make the address bar a shareable deep link to the row the user just opened. replaceState (not a
-		// location.hash assignment) adds no history entry and fires no hashchange, so it does not
-		// re-trigger applyHash. Collapsing deliberately leaves the fragment in place.
-		history.replaceState( null, '', '#' + subjectRowDomId( id ) );
+		// Make the address bar a shareable deep link to the row the user just opened. The fragment is the
+		// bare Subject id (like Wikibase's `#P123`); replaceState (not a location.hash assignment) adds no
+		// history entry and fires no hashchange, so it does not re-trigger applyHash. Collapsing
+		// deliberately leaves the fragment in place.
+		history.replaceState( null, '', '#' + id );
 	}
 	expandedIds.value = next;
 }
@@ -867,7 +868,7 @@ async function executeDelete( comment: string ): Promise<void> {
 }
 
 function applyHash(): void {
-	const id = subjectIdFromRowDomId( window.location.hash.slice( 1 ) );
+	const id = subjectIdFromHash( window.location.hash.slice( 1 ) );
 	if ( id === null ) {
 		return;
 	}

resources/ext.neowiki/src/presentation/subjectRowDomId.ts

@@ -1,22 +1,17 @@
 import { SubjectId } from '@/domain/SubjectId';
 
-// The DOM id — and, identically, the URL fragment — of a Subject's row on the Data tab
-// (?action=subjects). The subject-IRI dereference endpoint mints `#<domId>` into its Location when the
-// wiki targets the Data tab, and the Data tab reads the fragment back to expand, scroll to, and
-// highlight the row.
-//
-// Single source of truth for this scheme on the TypeScript side. Its PHP counterpart is SubjectRowAnchor
-// in src/Presentation/SubjectRowAnchor.php; the two must stay in lockstep. Each side has a test asserting
-// the same literal example, so a prefix change on one side alone breaks a test.
+// The DOM id of a Subject's row on the Data tab (?action=subjects). Internal rendering detail — HTML
+// hygiene and in-page scroll targeting — not a public contract. A row's public deep-link anchor is the
+// bare Subject id in the URL fragment (see subjectIdFromHash), which the mount handler resolves to a row
+// itself, so the fragment and this DOM id are decoupled.
 const ROW_ID_PREFIX = 'ext-neowiki-subject-row-';
 
 export function subjectRowDomId( subjectId: string ): string {
 	return ROW_ID_PREFIX + subjectId;
 }
 
-// The Subject id carried by a row DOM id (or the equivalent URL fragment), or null when the string is
-// not one of ours: it lacks the prefix, or the part after the prefix is not a valid Subject id. Callers
-// treat null as "nothing to do" (e.g. an unrelated fragment leaves the Data tab untouched).
+// The Subject id encoded in a row DOM id, or null when the string is not one of ours. Reads the Subject
+// off a dragged row element, whose id subjectRowDomId built.
 export function subjectIdFromRowDomId( domId: string ): string | null {
 	if ( !domId.startsWith( ROW_ID_PREFIX ) ) {
 		return null;
@@ -26,3 +21,11 @@ export function subjectIdFromRowDomId( domId: string ): string | null {
 
 	return SubjectId.isValid( subjectId ) ? subjectId : null;
 }
+
+// The Subject id carried by a Data tab URL fragment, or null when the fragment is not a Subject id (an
+// unrelated anchor, or junk — either leaves the Data tab untouched). The dereference endpoint's data-tab
+// Location and manual row expansion both write a bare Subject id as the fragment, like Wikibase's
+// `#P123`; this reads it back. Deliberately the Subject id, not the row DOM id.
+export function subjectIdFromHash( hash: string ): string | null {
+	return SubjectId.isValid( hash ) ? hash : null;
+}

resources/ext.neowiki/tests/presentation/subjectRowDomId.spec.ts

@@ -1,49 +1,50 @@
 import { describe, it, expect } from 'vitest';
-import { subjectRowDomId, subjectIdFromRowDomId } from '@/presentation/subjectRowDomId';
+import { subjectRowDomId, subjectIdFromRowDomId, subjectIdFromHash } from '@/presentation/subjectRowDomId';
 
 const VALID_ID = 's12345abcdefghj';
 
-describe( 'subjectRowDomId', () => {
+// The internal row DOM id (rendering + reading the Subject off a dragged row), not a public contract.
+describe( 'subjectRowDomId / subjectIdFromRowDomId', () => {
 
-	// The same literal example is asserted by the PHP counterpart
-	// (tests/phpunit/Presentation/SubjectRowAnchorTest.php). Keep them identical so a prefix change on
-	// either side breaks a test.
-	it( 'prefixes the subject id', () => {
-		expect( subjectRowDomId( VALID_ID ) ).toBe( 'ext-neowiki-subject-row-s12345abcdefghj' );
-	} );
-
-} );
-
-describe( 'subjectIdFromRowDomId', () => {
-
-	it( 'round-trips a row DOM id back to its subject id', () => {
+	it( 'round-trips a subject id through its row DOM id', () => {
 		expect( subjectIdFromRowDomId( subjectRowDomId( VALID_ID ) ) ).toBe( VALID_ID );
 	} );
 
-	it( 'returns null for a bare subject id without the row prefix', () => {
+	it( 'returns null for a string without the row prefix', () => {
 		expect( subjectIdFromRowDomId( VALID_ID ) ).toBeNull();
 	} );
 
 	it( 'returns null when the prefix is present but the body is not a valid subject id', () => {
 		expect( subjectIdFromRowDomId( subjectRowDomId( 'not-a-valid-id' ) ) ).toBeNull();
 	} );
 
-	it( 'returns null for the prefix with an empty body', () => {
-		expect( subjectIdFromRowDomId( 'ext-neowiki-subject-row-' ) ).toBeNull();
-	} );
-
-	it( 'returns null for an unrelated fragment', () => {
-		expect( subjectIdFromRowDomId( 'section-heading' ) ).toBeNull();
-	} );
-
 	it( 'returns null for a same-length prefix that is not ours', () => {
 		// 'ext-neowiki-subject-ROW-' is 24 characters like the real prefix but differs in case, so a
 		// naive slice without a prefix check would wrongly extract a valid id from it.
 		expect( subjectIdFromRowDomId( 'ext-neowiki-subject-ROW-' + VALID_ID ) ).toBeNull();
 	} );
 
-	it( 'returns null for an empty string', () => {
-		expect( subjectIdFromRowDomId( '' ) ).toBeNull();
+} );
+
+// The public deep-link contract: a Data tab URL fragment is a bare Subject id (like Wikibase's #P123).
+describe( 'subjectIdFromHash', () => {
+
+	it( 'accepts a bare subject-id-shaped fragment', () => {
+		expect( subjectIdFromHash( VALID_ID ) ).toBe( VALID_ID );
+	} );
+
+	it( 'returns null for a fragment that is not a subject id', () => {
+		expect( subjectIdFromHash( 'section-heading' ) ).toBeNull();
+	} );
+
+	it( 'returns null for an empty fragment', () => {
+		expect( subjectIdFromHash( '' ) ).toBeNull();
+	} );
+
+	it( 'does not accept the internal row DOM id form as a fragment', () => {
+		// The old scheme put the row DOM id in the fragment; the contract is now the bare Subject id, and
+		// the long form must not be silently accepted.
+		expect( subjectIdFromHash( subjectRowDomId( VALID_ID ) ) ).toBeNull();
 	} );
 
 } );

src/EntryPoints/REST/ResolveSubjectIriApi.php

@@ -14,7 +14,6 @@
 use ProfessionalWiki\NeoWiki\EntryPoints\Actions\SubjectsAction;
 use ProfessionalWiki\NeoWiki\NeoWikiExtension;
 use ProfessionalWiki\NeoWiki\Presentation\SubjectDereferenceTarget;
-use ProfessionalWiki\NeoWiki\Presentation\SubjectRowAnchor;
 use Wikimedia\ParamValidator\ParamValidator;
 
 /**
@@ -104,9 +103,8 @@ private function hostingPageRedirect( string $subjectId, PageIdentifiers $hostin
 	private function hostingPageUrl( Title $title, string $subjectId ): string {
 		if ( $this->dereferenceTarget() === SubjectDereferenceTarget::DataTab ) {
 			// The Data tab reads this fragment on mount to expand, scroll to, and highlight the row. The
-			// fragment is the row's DOM id; {@see SubjectRowAnchor} is the PHP source of truth for that scheme.
-			return $title->getCanonicalURL( [ 'action' => SubjectsAction::ACTION_NAME ] )
-				. '#' . SubjectRowAnchor::domId( $subjectId );
+			// fragment is the bare Subject id (like Wikibase's `#P123`), not the row's internal DOM id.
+			return $title->getCanonicalURL( [ 'action' => SubjectsAction::ACTION_NAME ] ) . '#' . $subjectId;
 		}
 
 		return $title->getCanonicalURL();

src/Presentation/SubjectRowAnchor.php

@@ -13,7 +13,6 @@
 use ProfessionalWiki\NeoWiki\Domain\Schema\SchemaName;
 use ProfessionalWiki\NeoWiki\Domain\Subject\SubjectLabel;
 use ProfessionalWiki\NeoWiki\EntryPoints\REST\ResolveSubjectIriApi;
-use ProfessionalWiki\NeoWiki\Presentation\SubjectRowAnchor;
 use ProfessionalWiki\NeoWiki\Tests\Data\TestSubject;
 use ProfessionalWiki\NeoWiki\Tests\NeoWikiIntegrationTestCase;
 use ProfessionalWiki\NeoWiki\Tests\NeoWikiMockAuthorityTrait;
@@ -35,6 +34,11 @@ class ResolveSubjectIriApiTest extends NeoWikiIntegrationTestCase {
 	public function setUp(): void {
 		$this->setUpNeo4j();
 
+		// Pin the default dereference target so the Accept-negotiation tests are independent of any
+		// ambient $wgNeoWikiSubjectDereferenceTarget (e.g. a dev LocalSettings override). Tests that
+		// exercise a specific target override this.
+		$this->overrideConfigValue( 'NeoWikiSubjectDereferenceTarget', 'page' );
+
 		$this->createSchema( self::SCHEMA );
 
 		$this->pageId = $this->createPageWithSubjects(
@@ -104,15 +108,6 @@ public function testAbsentAcceptRedirectsToTheHostingPage(): void {
 		$this->assertHostingPageLocation( $response );
 	}
 
-	public function testPageDereferenceTargetRedirectsToThePlainHostingPage(): void {
-		$this->overrideConfigValue( 'NeoWikiSubjectDereferenceTarget', 'page' );
-
-		$response = $this->deref( headers: [ 'Accept' => 'text/html' ] );
-
-		$this->assertSame( 303, $response->getStatusCode() );
-		$this->assertHostingPageLocation( $response );
-	}
-
 	public function testDataTabDereferenceTargetRedirectsToTheSubjectsRow(): void {
 		$this->overrideConfigValue( 'NeoWikiSubjectDereferenceTarget', 'data-tab' );
 
@@ -129,9 +124,9 @@ public function testDataTabDereferenceTargetRedirectsToTheSubjectsRow(): void {
 		);
 		$this->assertStringContainsString( 'action=subjects', $location, 'The redirect opens the Data tab.' );
 		$this->assertStringEndsWith(
-			'#' . SubjectRowAnchor::domId( self::SUBJECT_ID ),
+			'#' . self::SUBJECT_ID,
 			$location,
-			'The fragment is the Subject row anchor the Data tab expands and highlights.'
+			'The fragment is the bare Subject id the Data tab expands and highlights.'
 		);
 	}