Make possible the use of @id in hasComponent-entities (exemplar)

rest/src/main/groovy/whelk/rest/api/Crud.groovy

@@ -167,11 +167,17 @@ class Crud extends HttpServlet {
                           HttpServletResponse response) {
         Tuple2<Document, String> docAndLocation
 
-        if (request.getId() in cachedFetches) {
-            docAndLocation = cachedFetches[request.getId()]
+        // If a component-IRI is requested - we quietly and internally redirect the request to fetch the
+        // containing record instead.
+        // If there isn't one, fall back to whatever was expressly asked for (necessary for special iris like vocab).
+        String id = whelk.getStorage().getSystemIdByIri(Document.BASE_URI.toString() + request.getId())
+        if (id == null)
+            id = request.getId()
+
+        if (id in cachedFetches) {
+            docAndLocation = cachedFetches[id]
         } else {
-            docAndLocation = getDocumentFromStorage(
-                    request.getId(), request.getVersion().orElse(null))
+            docAndLocation = getDocumentFromStorage(id, request.getVersion().orElse(null))
         }
 
         Document doc = docAndLocation.v1
@@ -190,7 +196,7 @@ class Crud extends HttpServlet {
             History history = new History(whelk.storage.loadDocumentHistory(doc.getShortId()), jsonld)
             ETag eTag = ETag.plain(doc.getChecksum(jsonld))
             def body = history.m_changeSetsMap
-            sendGetResponse(response, body, eTag, request.getPath(), request.getContentType(), request.getId())
+            sendGetResponse(response, body, eTag, request.getPath(), request.getContentType(), id)
         } else {
             ETag eTag
             if (request.shouldEmbellish()) {
@@ -219,7 +225,7 @@ class Crud extends HttpServlet {
             String location = loc ?: doc.id
             addProposal25Headers(response, location, getDataURI(location, request))
 
-            sendGetResponse(response, body, eTag, request.getPath(), request.getContentType(), request.getId())
+            sendGetResponse(response, body, eTag, request.getPath(), request.getContentType(), id)
         }
     }
 

whelk-core/src/main/groovy/whelk/Document.groovy

@@ -45,6 +45,7 @@ class Document {
     static final List thingIdPath2 = ["@graph", 1, "@id"]
     static final List thingTypePath = ["@graph", 1, "@type"]
     static final List thingSameAsPath = ["@graph", 1, "sameAs"]
+    static final List thingComponentPath = ["@graph", 1, "hasComponent"]
     static final List thingTypedIDsPath = ["@graph", 1, "identifiedBy"]
     static final List thingIndirectTypedIDsPath = ["@graph", 1, "indirectlyIdentifiedBy"]
     static final List thingCarrierTypesPath = ["@graph", 1, "carrierType"]
@@ -441,6 +442,18 @@ class Document {
         return ret
     }
 
+    List<String> getThingComponentIdentifiers() {
+        List<String> ret = []
+
+        List componentObjects = get(thingComponentPath)
+        for (Map object : componentObjects) {
+            if (object.get("@id") != null)
+                ret.add(object.get("@id"))
+        }
+
+        return ret
+    }
+
     void addThingIdentifier(String identifier) {
         if (get(thingIdPath) == null) {
             set(thingIdPath2, identifier)
@@ -869,6 +882,15 @@ class Document {
         }
     }
 
+    void mintComponentIDs() {
+        List componentObjects = get(thingComponentPath)
+        for (Map object : componentObjects) {
+            Object existingId = object.get("@id")
+            if (existingId != null && existingId.contains("TEMPID"))
+                object.put("@id", BASE_URI.toString() + IdGenerator.generate())
+        }
+    }
+
     void applyInverses(JsonLd jsonld) {
         Map thing = get(thingPath)
         jsonld.applyInverses(thing)

whelk-core/src/main/groovy/whelk/component/PostgreSQLComponent.groovy

@@ -1008,6 +1008,7 @@ class PostgreSQLComponent {
                 }
             }
 
+            doc.mintComponentIDs()
             if (doVerifyDocumentIdRetention) {
                 verifyDocumentIdRetention(preUpdateDoc, doc, connection)
             }
@@ -1098,11 +1099,13 @@ class PostgreSQLComponent {
         HashSet<String> oldIDs = new HashSet<>()
         oldIDs.addAll( preUpdateDoc.getRecordIdentifiers() )
         oldIDs.addAll( preUpdateDoc.getThingIdentifiers() )
+        oldIDs.addAll( preUpdateDoc.getThingComponentIdentifiers() )
 
         // Compile list of all new IDs
         HashSet<String> newIDs = new HashSet<>()
         newIDs.addAll( postUpdateDoc.getRecordIdentifiers() )
         newIDs.addAll( postUpdateDoc.getThingIdentifiers() )
+        newIDs.addAll( postUpdateDoc.getThingComponentIdentifiers() )
 
         // (#work identifiers integrity is not enforced, because doing so would disable breaking out works.)
 
@@ -1550,6 +1553,16 @@ class PostgreSQLComponent {
                 }
             }
         }
+        for (altThingId in doc.getThingComponentIdentifiers()) {
+            // don't re-add thing identifiers if doc is deleted
+            if (!deleted) {
+                altIdInsert.setString(1, doc.getShortId())
+                altIdInsert.setString(2, altThingId)
+                altIdInsert.setInt(3, 1) // thing id -> graphIndex = 1
+                altIdInsert.setBoolean(4, false) // alternative ID
+                altIdInsert.addBatch()
+            }
+        }
         try {
             altIdInsert.executeBatch()
         } catch (BatchUpdateException bue) {

whelk-core/src/main/groovy/whelk/filter/LinkFinder.groovy

@@ -134,9 +134,12 @@ class LinkFinder {
         // Keep looking for more links
         for (Object key : data.keySet()) {
 
-            // sameAs objects are not links per se, and must not be replaced
+            // sameAs objects are not links per se, and must not be replaced.
+            // itemUsed is used to target specific components of holding records. If we let those
+            // be upgraded, links to those specific components would be lost (replaced with links
+            // to the record as a whole). So we don't upgrade them. This is a cheat/hack. :(
             String keyString = (String) key
-            if (keyString == "sameAs")
+            if (keyString == "sameAs" || keyString == "itemUsed")
                 continue
 
             Object value = data.get(key)
@@ -174,7 +177,7 @@ class LinkFinder {
     /**
      * A heavy-handed last line of defense against confusing embedded entities with references.
      * After running this, 'document' can no longer have both @id and other data in any same
-     * embedded entity (root entities are exempt).
+     * embedded entity (root entities and root entites under hasComponent are exempt).
      */
     private void clearReferenceAmbiguities(Document document) {
         List graphList = document.data.get(JsonLd.GRAPH_KEY)
@@ -217,19 +220,22 @@ class LinkFinder {
         for (Object key : data.keySet()) {
             Object value = data.get(key)
 
+            // Components must themselves be considered "root" entities, as they must be allowed both @id and data.
+            boolean viewNextAsRoot = key.equals("hasComponent")
+
             if (value instanceof List)
-                clearReferenceAmbiguities_internal( (List) value )
+                clearReferenceAmbiguities_internal( (List) value, viewNextAsRoot )
             if (value instanceof Map)
-                clearReferenceAmbiguities_internal( (Map) value, false )
+                clearReferenceAmbiguities_internal( (Map) value, viewNextAsRoot )
         }
     }
 
-    private void clearReferenceAmbiguities_internal(List data) {
+    private void clearReferenceAmbiguities_internal(List data, boolean isRootEntry) {
         for (Object element : data){
             if (element instanceof List)
-                clearReferenceAmbiguities_internal( (List) element )
+                clearReferenceAmbiguities_internal( (List) element, false )
             else if (element instanceof Map)
-                clearReferenceAmbiguities_internal( (Map) element, false )
+                clearReferenceAmbiguities_internal( (Map) element, isRootEntry )
         }
     }
 }