Add matchedNotation field to search results for notation matches

[fvogel]

Summary

Fixes #1931 — adds a matchedNotation field to REST API search results when a concept is found via its skos:notation, parallel to the existing matchedPrefLabel for prefLabel matches.

Changes in src/model/sparql/GenericSparql.php:

• Add BIND(IF((?pri = "5" || ?pri = "6"), ?match, ?unbound) as ?nlabel) in the $labelpriority block
• Add ?nlabel to SELECT and GROUP BY clauses
• Add elseif (isset($row->nlabel)) handler setting $hit['matchedNotation']

Before (notation search query=A.1):

{ "prefLabel": "Cat", "notation": "A.1" }

After:

{ "prefLabel": "Cat", "notation": "A.1", "matchedNotation": "A.1" }

Test plan

• query=A.1 → result includes matchedNotation: "A.1"
• query=A.1.1 → result includes matchedNotation: "A.1.1"
• query=Cat → no matchedNotation field (prefLabel match, correct)
• Existing PHPUnit tests pass

Tested against Skosmos 3.1 with Fuseki 5.4.0, searchByNotation true, sparqlDialect "JenaText".

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[osma]

Thank you for the suggested enhancement and the PR to implement it.

It all looks good except for one rather minor detail: I don't like the SPARQL variable name ?nlabel because a notation is not a label. I understand this name is intended to match the style of ?alabel and ?hlabel for altLabels and hiddenLabels, respectively. In hindsight, maybe those variable names were not so clear from the start.

OTOH, the variable ?notation is already in use for returning the notation (regardless of whether it was matched) so renaming ?nlabel to ?notation is not possible either.

I suggest renaming ?nlabel to ?nmatch and then also renaming ?alabel to ?amatch and ?hlabel to ?hmatch. This needs to be done in a few different places in the code. Once this is done then all three variable names are clearer than they are currently and align well with each other.

[osma]

Also, we would like to have PHPUnit tests for features like this. It could go into GenericSparqlTest. Though I admit that we don't have 100% coverage for search functionality, at least it would be good not to decrease it.