DS-2077 Sort collections by full path

This commit fixes the order of collection drop-down entries when starting a
submission and when editing e-mail subscriptions such that the community
hierarchy is taken into account as well as the collection name. The change in
CollectionDropDown makes the same mechanism re-usable in other places where
this might be required.

dspace-api/src/main/java/org/dspace/app/util/CollectionDropDown.java

@@ -8,6 +8,8 @@
 package org.dspace.app.util;
 
 import java.sql.SQLException;
+import java.util.*;
+
 import org.dspace.content.Collection;
 import org.dspace.content.Community;
 import org.dspace.core.ConfigurationManager;
@@ -71,4 +73,63 @@ public class CollectionDropDown {
 
         return name.toString();
     }
+
+	/**
+	 * Annotates an array of collections with their respective full paths (@see #collectionPath() method in this class).
+	 * @param collections An array of collections to annotate with their hierarchical paths.
+	 *                       The array and all its entries must be non-null.
+	 * @return A sorted array of collection path entries (essentially collection/path pairs).
+	 * @throws SQLException In case there are problems annotating a collection with its path.
+	 */
+	public static CollectionPathEntry[] annotateWithPaths(Collection[] collections) throws SQLException
+	{
+		CollectionPathEntry[] result = new CollectionPathEntry[collections.length];
+		for (int i = 0; i < collections.length; i++)
+		{
+			Collection collection = collections[i];
+			CollectionPathEntry entry = new CollectionPathEntry(collection, collectionPath(collection));
+			result[i] = entry;
+		}
+		Arrays.sort(result);
+		return result;
+	}
+
+	/**
+	 * A helper class to hold (collection, full path) pairs. Instances of the helper class are sortable:
+	 * two instances will be compared first on their full path and if those are equal,
+	 * the comparison will fall back to comparing collection IDs.
+	 */
+	public static class CollectionPathEntry implements Comparable<CollectionPathEntry>
+	{
+		public Collection collection;
+		public String path;
+
+		public CollectionPathEntry(Collection collection, String path)
+		{
+			this.collection = collection;
+			this.path = path;
+		}
+
+		@Override
+		public int compareTo(CollectionPathEntry other)
+		{
+			if (!this.path.equals(other.path))
+			{
+				return this.path.compareTo(other.path);
+			}
+			return Integer.compare(this.collection.getID(), other.collection.getID());
+		}
+
+		@Override
+		public boolean equals(Object o)
+		{
+			return o != null && o instanceof CollectionPathEntry && this.compareTo((CollectionPathEntry) o) == 0;
+		}
+
+		@Override
+		public int hashCode()
+		{
+			return Objects.hash(path, collection.getID());
+		}
+	}
 }

dspace-xmlui/src/main/java/org/dspace/app/xmlui/aspect/eperson/EditProfile.java

@@ -375,11 +375,12 @@ public class EditProfile extends AbstractDSpaceTransformer
            subscriptions.enableDeleteOperation();
            
            subscriptions.addOption(-1,T_select_collection);
-           for (Collection possible : possibleList)
+	       CollectionDropDown.CollectionPathEntry[] possibleEntries = CollectionDropDown.annotateWithPaths(possibleList);
+           for (CollectionDropDown.CollectionPathEntry possible : possibleEntries)
            {
-               subscriptions.addOption(possible.getID(), CollectionDropDown.collectionPath(possible));
+               subscriptions.addOption(possible.collection.getID(), possible.path);
            }
-                   
+
            for (Collection collection: currentList)
            {
                subscriptions.addInstance().setOptionSelected(collection.getID());

dspace-xmlui/src/main/java/org/dspace/app/xmlui/aspect/submission/submit/SelectCollectionStep.java

@@ -98,9 +98,10 @@ public class SelectCollectionStep extends AbstractSubmissionStep
         select.setHelp(T_collection_help);
         
         select.addOption("",T_collection_default);
-        for (Collection collection : collections) 
+	    CollectionDropDown.CollectionPathEntry[] collectionPaths = CollectionDropDown.annotateWithPaths(collections);
+        for (CollectionDropDown.CollectionPathEntry entry : collectionPaths)
         {
-            select.addOption(collection.getHandle(), CollectionDropDown.collectionPath(collection));
+            select.addOption(entry.collection.getHandle(), entry.path);
         }
         
         Button submit = list.addItem().addButton("submit");