Core: extend meta model by "Ordered" flag (#340).

Both, "Composition Definition" and "Aggregation Definition" have a new boolean child type: "Ordered" (dm4.core.ordered).

COMPATIBILITY NOTE:
For a production instance a migration must be supplied that adds the "Ordered" type.

See ticket 340.

modules/dm4-core/src/main/java/de/deepamehta/core/impl/service/AttachedType.java

@@ -20,7 +20,7 @@
 import de.deepamehta.core.util.DeepaMehtaUtils;
 
 import java.util.ArrayList;
-import java.util.Arrays;
+import static java.util.Arrays.asList;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -304,22 +304,20 @@ private void initAssociationDefinitions() {
 
     private Map<Long, AssociationDefinition> fetchAssociationDefinitions() {
         // 1) fetch part topic types
-        // Note: the low-level storage call prevents possible endless recursion (caused by POST_FETCH_HOOK).
-        // Consider the Access Control plugin: loading topic type dm4.accesscontrol.acl_facet would imply
-        // loading its ACL which in turn would rely on this very topic type.
-        // ### FIXME: is this still true? The POST_FETCH_HOOK is dropped meanwhile.
-        List assocTypeFilter = Arrays.asList("dm4.core.aggregation_def", "dm4.core.composition_def");
-        ResultSet<RelatedTopicModel> partTopicTypes = dms.storage.getTopicRelatedTopics(getId(), assocTypeFilter,
-            "dm4.core.whole_type", "dm4.core.part_type", "dm4.core.topic_type", 0);
+        // Note: we must set fetchRelatingComposite to false here. Fetching the composite of association type
+        // Composition Definition would cause an endless recursion. Composition Definition is defined through
+        // Composition Definition itself (child types "Include in Label", "Ordered").
+        ResultSet<RelatedTopic> partTopicTypes = getRelatedTopics(asList("dm4.core.aggregation_def",
+            "dm4.core.composition_def"), "dm4.core.whole_type", "dm4.core.part_type", "dm4.core.topic_type",
+            false, false, 0, null);     // fetchComposite=false, fetchRelatingComposite=false
         //
         // 2) create association definitions
         // Note: the returned map is an intermediate, hashed by ID. The actual type model is
         // subsequently build from it by sorting the assoc def's according to the sequence IDs.
         Map<Long, AssociationDefinition> assocDefs = new HashMap();
-        for (RelatedTopicModel partTopicType : partTopicTypes) {
-            Association assoc = new AttachedAssociation(partTopicType.getAssociationModel(), dms);
-            AssociationDefinition assocDef = dms.objectFactory.fetchAssociationDefinition(assoc, getUri(),
-                partTopicType.getId());
+        for (RelatedTopic partTopicType : partTopicTypes) {
+            AssociationDefinition assocDef = dms.objectFactory.fetchAssociationDefinition(
+                partTopicType.getAssociation(), getUri(), partTopicType.getId());
             assocDefs.put(assocDef.getId(), assocDef);
         }
         return assocDefs;

modules/dm4-core/src/main/resources/migrations/migration2.json

@@ -6,6 +6,11 @@
             value:         "Include in Label",
             uri:           "dm4.core.include_in_label",
             data_type_uri: "dm4.core.boolean"
+        },
+        {
+            value:         "Ordered",
+            uri:           "dm4.core.ordered",
+            data_type_uri: "dm4.core.boolean"
         }
     ],
 
@@ -21,6 +26,11 @@
                     part_topic_type_uri:  "dm4.core.include_in_label",
                     part_cardinality_uri: "dm4.core.one",
                     assoc_type_uri:       "dm4.core.composition_def"
+                },
+                {
+                    part_topic_type_uri:  "dm4.core.ordered",
+                    part_cardinality_uri: "dm4.core.one",
+                    assoc_type_uri:       "dm4.core.composition_def"
                 }
             ]
         },
@@ -33,6 +43,11 @@
                     part_topic_type_uri:  "dm4.core.include_in_label",
                     part_cardinality_uri: "dm4.core.one",
                     assoc_type_uri:       "dm4.core.composition_def"
+                },
+                {
+                    part_topic_type_uri:  "dm4.core.ordered",
+                    part_cardinality_uri: "dm4.core.one",
+                    assoc_type_uri:       "dm4.core.composition_def"
                 }
             ]
         }