preparing to load tags alongside with project tasks

tags/src/main/java/de/srsoftware/umbrella/tags/SqliteDb.java

@@ -253,8 +253,13 @@ CREATE TABLE IF NOT EXISTS {0} (
 	public Set<String> list(long userId, String module, long entityId) {
 		try {
 			var tags = new HashSet<String>();
+
+			// load tags assigned to user
 			var rs = select(TAG).from(TABLE_TAGS).where(MODULE,equal(module)).where(ENTITY_ID,equal(entityId)).where(USER_ID,equal(userId)).exec(db);
 			while (rs.next()) tags.add(rs.getString(1));
+			rs.close();
+
+			// load tags assigned to no user
 			rs = select(TAG).from(TABLE_TAGS).where(MODULE,equal(module)).where(ENTITY_ID,equal(entityId)).where(USER_ID,isNull()).exec(db);
 			while (rs.next()) tags.add(rs.getString(1));
 			rs.close();
@@ -264,6 +269,26 @@ CREATE TABLE IF NOT EXISTS {0} (
 		}
 	}
 
+	@Override
+	public Map<Long, ? extends Collection<String>> list(long userId, String module, Collection<Long> entityIds) {
+		try {
+			var tags = new HashMap<Long,HashSet<String>>();
+
+			// load tags assigned to user
+			var rs = select(ENTITY_ID,TAG).from(TABLE_TAGS).where(MODULE,equal(module)).where(ENTITY_ID,in(entityIds.toArray())).where(USER_ID,equal(userId)).exec(db);
+			while (rs.next()) tags.computeIfAbsent(rs.getLong(ENTITY_ID), k -> new HashSet<>()).add(rs.getString(TAG));
+			rs.close();
+
+			// load tags assigned to no user
+			rs = select(TAG).from(TABLE_TAGS).where(MODULE,equal(module)).where(ENTITY_ID,in(entityIds.toArray())).where(USER_ID,isNull()).exec(db);
+			while (rs.next()) tags.computeIfAbsent(rs.getLong(ENTITY_ID), k -> new HashSet<>()).add(rs.getString(TAG));
+			rs.close();
+			return tags;
+		} catch (SQLException e) {
+			throw new UmbrellaException("Failed to load tags");
+		}
+	}
+
 	@Override
 	public void save(Collection<Long> userIds, String module, long entityId, Collection<String> tags) {
 		try {

tags/src/main/java/de/srsoftware/umbrella/tags/TagDB.java

@@ -1,6 +1,8 @@
 /* © SRSoftware 2025 */
 package de.srsoftware.umbrella.tags;
 
+import de.srsoftware.umbrella.core.exceptions.UmbrellaException;
+
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -15,8 +17,16 @@ public interface TagDB {
 
 	Set<String> list(long userId, String module, long entityId);
 
+	/**
+	 * Loads the tags for all the entities denominated by the collection <em>entityIds</em>.
+	 * @param module the realm the entities belong to
+	 * @param entityIds the set of entities of the respective realm
+	 * @param userId the id of the user, for whom the tags shall be loaded
+	 * @return a map from entity ids to assigned tags
+	 */
+	Map<Long, ? extends Collection<String>> list(long userId, String module, Collection<Long> entityIds);
+
 	void save(Collection<Long> userIds, String module, long entityId, Collection<String> tags);
 
 	void updateId(String module, Object oldId, Object newId);
-
 }

tags/src/main/java/de/srsoftware/umbrella/tags/TagModule.java

@@ -121,6 +121,11 @@ public class TagModule extends BaseHandler implements TagService {
 		return tagDb.list(user.id(),module,entityId);
 	}
 
+	@Override
+	public Map<Long, ? extends Collection<String>> getTags(String module, Collection<Long> entityIds, UmbrellaUser user) throws UmbrellaException {
+		return tagDb.list(user.id(),module,entityIds);
+	}
+
 	@Override
 	public void save(String module, long entityId, Collection<Long> userIds, Collection<String> tags) {
 		tagDb.save(userIds,module,entityId,tags);