--- a/flys-client/ChangeLog	Tue Oct 11 13:25:18 2011 +0000
+++ b/flys-client/ChangeLog	Wed Oct 12 06:59:42 2011 +0000
@@ -1,3 +1,18 @@
+2011-10-12  Felix Wolfsteller <felix.wolfsteller@intevation.de>
+
+	Partial fix for flys/issue304 [1] (Erweiterte Funktionen W-Differenzen),
+	enable multiple clones of same recommendation, but be 'sparse'.
+
+	* src/main/java/de/intevation/flys/client/server/LoadArtifactServiceImpl.java
+	  (loadMany): While iterating over recommendations and creating
+	  clones, keep track of results, do not clone a second time if same
+	  recommendation is present multiple times in list, use "old" clone
+	  instead. Throw excpetion in fail-case.
+
+	* src/main/java/de/intevation/flys/client/client/ui/DatacageTwinPanel.java:
+	  Use list instead of set, 'sparseness' is now achieved by
+	  LoadArtifactService. Docs, removed junk.
+
 2011-10-11  Ingo Weinzierl <ingo@intevation.de>
 
 	flys/issue300 (ÜSK: Reihenfolge der Ebenen findet keine Berücksichtigung)

--- a/flys-client/src/main/java/de/intevation/flys/client/client/ui/DatacageTwinPanel.java	Tue Oct 11 13:25:18 2011 +0000
+++ b/flys-client/src/main/java/de/intevation/flys/client/client/ui/DatacageTwinPanel.java	Wed Oct 12 06:59:42 2011 +0000
@@ -1,7 +1,6 @@
 package de.intevation.flys.client.client.ui;
 
 import java.util.ArrayList;
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -188,6 +187,7 @@
             // TODO i18n of error message. (MSG.no_waterlevel_pair_selected())
             errors.add("No pair of waterlevel items selected");
         }
+        // Check whether minuend and subtrahend are equal.
 
         return errors;
     }
@@ -230,9 +230,12 @@
         Config config = Config.getInstance();
         ListGridRecord[] records = differencesList.getRecords();
 
-        // Use LinkedHashSet to keep the order.
-        Set<Recommendation> ar  = new LinkedHashSet<Recommendation>();
-        Set<Recommendation> all = new LinkedHashSet<Recommendation>();
+        // TODO Problem when same facet participates in two diffs.
+        //
+        // Resolve whether "new" ones were already cloned.
+
+        List<Recommendation> ar  = new ArrayList<Recommendation>();
+        List<Recommendation> all = new ArrayList<Recommendation>();
         for (ListGridRecord record : records) {
             RecommendationPairRecord r =
                 (RecommendationPairRecord) record;
@@ -301,6 +304,9 @@
     }
 
 
+    /**
+     * Creates part of the String that encodes minuend or subtrahend.
+     */
     protected String createDataString(String artifact, Filter filter) {
         Facet f = null;
 
@@ -318,19 +324,5 @@
 
         return "[" + artifact + ";" + f.getName() + ";" + f.getIndex() + "]";
     }
-
-    /*@Override
-    protected Data[] getData() {
-        // TODO ToLoadRecord ! 
-        String value = "TODO:FIND VALUE";
-        if (toLoad1 != null) {
-            List<Recommendation> recommendations = toLoad1.toRecommendations();
-            value = recommendations.get(0).getIDs();
-        }
-        DataItem item1 = new DefaultDataItem(dataName, dataName, value);
-        DataItem item2 = new DefaultDataItem(dataName, dataName, value);
-        return new Data[] { new DefaultData(
-            dataName, null, null, new DataItem[] { item1, item2}) };
-    }*/
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

--- a/flys-client/src/main/java/de/intevation/flys/client/server/LoadArtifactServiceImpl.java	Tue Oct 11 13:25:18 2011 +0000
+++ b/flys-client/src/main/java/de/intevation/flys/client/server/LoadArtifactServiceImpl.java	Wed Oct 12 06:59:42 2011 +0000
@@ -1,6 +1,7 @@
 package de.intevation.flys.client.server;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 
 import de.intevation.flys.client.shared.exceptions.ServerException;
 import de.intevation.flys.client.shared.model.Artifact;
@@ -53,11 +54,13 @@
 
 
     /**
-     * Clone one or more artifacts and add it to a collection.
+     * Clone one or more artifacts and add it to a collection, avoid duplicates.
      *
      * @param parent Collection where clones will be added to.
      * @param recommendations definitions of source of clone.
      * @param factory name of factory to use when cloning artifacts.
+     * @return cloned artifacts (same artifact might be contained multiple
+     *         times).
      */
     public Artifact[] loadMany(
         Collection       parent,
@@ -67,32 +70,46 @@
         String           locale
     )
     throws ServerException {
-        System.out.println("LoadArtifactServiceImpl.loadMany: "
-            + recoms[0].getMasterArtifact());
+        System.out.println("LoadArtifactServiceImpl.loadMany");
         ArrayList<Artifact> artifacts = new ArrayList<Artifact>();
+        HashMap<Recommendation, Artifact> cloneMap =
+            new HashMap<Recommendation, Artifact>();
 
         // TODO Respect the index of what to clone.
 
-        // 1) Clone the Artifacts specified in >>recom<<
+        // 1) Clone the Artifacts specified in >>recoms<<
         for (Recommendation recom : recoms) {
-            Artifact clone = ArtifactHelper.createArtifact(
-                url, locale, factory, recom);
-    
-            if (clone != null) {
-                System.out.println("Successfully create Artifact Clone. Add now!");
-                Collection c = CollectionHelper.addArtifact(
-                    parent, clone, url, locale);
-    
-                if (c != null) {
-                    System.out.println("Successfully added Clone to Collection.");
-    
-                    artifacts.add(clone);
+            // Do not do two clones of two identical recommendations.
+            Artifact prevClone = cloneMap.get(recom);
+            if (prevClone != null) {
+                // Already cloned a recommendation like this.
+                System.out.println("LoadArtifactServiceImpl: Avoid reclones, "
+                    + "clone already exists.");
+                artifacts.add(prevClone);
+            }
+            else {
+                // Not already cloned.
+                Artifact clone = ArtifactHelper.createArtifact(
+                    url, locale, factory, recom);
+        
+                if (clone != null) {
+                    System.out.println("LoadArtifactServiceImple: Successfully "
+                        + "loaded Artifact Clone.");
+                    Collection c = CollectionHelper.addArtifact(
+                        parent, clone, url, locale);
+        
+                    if (c != null) {
+                        artifacts.add(clone);
+                        // Remember we cloned a recommendation like this.
+                        cloneMap.put(recom, clone);
+                    }
+                    else {
+                        throw new ServerException(ERROR_LOAD_ARTIFACT);
+                    }
                 }
             }
         }
         return artifacts.toArray(new Artifact[artifacts.size()]);
-
-        //throw new ServerException(ERROR_LOAD_ARTIFACT);
     }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :