get interwiki links

modules/fontane/index-processor.xqm

@@ -225,7 +225,9 @@ declare function local:idno($idnos as element()*)
 as element(xhtml:li)* {
 for $idno in $idnos
 let $str := string($idno)
-let $wikipedia := if($idno/@type = "GND") then local:gnd-wikipedia($str) else ()
+let $wikipedia :=
+  if($idno/@type = "GND") then local:gnd-wikipedia($str) else
+  if($idno/@type = "Wikidata") then local:wikidata-wikipedia($str) else ()
 return
     element xhtml:li {
         attribute class {"idno"},
@@ -286,6 +288,21 @@ return
     string($response//foaf:page/@rdf:resource)
 };
 
+declare function local:wikidata-wikipedia($wikidata-id as xs:string)
+as xs:string?{
+  let $query := escape-uri("SELECT ?s WHERE{?s schema:about wd:" || $wikidata-id || ".}", true())
+  let $url := "https://query.wikidata.org/sparql?query=" || $query
+  let $persist := false()
+  let $request-headers := ()
+  let $uris := httpclient:get(xs:anyURI($url), $persist, $request-headers)//*:uri/string()
+  return (
+    $uris[matches(., "de\.wikipedia")],
+    $uris[matches(., "en\.wikipedia")],
+    $uris[matches(., "fr\.wikipedia")],
+    $uris[matches(., "it\.wikipedia")],
+    $uris[1])[1]
+};
+
 (:~
  : transformation from tei:note to xhtml:li
  :  :)