CAY-2976 Exception creating a relationship for an Incomplete ObjEntity

Author: andrus

RELEASE-NOTES.txt

@@ -39,6 +39,7 @@ CAY-2966 "comment" field is lost when upgrading from v10 to v12
 CAY-2967 SQLTemplate/SQLSelect broken pagination
 CAY-2968 Vertical Inheritance: INSERT instead of UPDATE after updating flattened attribute
 CAY-2973 Exception trying to copy/paste a callback
+CAY-2976 Exception creating a relationship for an Incomplete ObjEntity
 
 ----------------------------------
 Release: 5.0-M2

modeler/cayenne-modeler/src/main/java/org/apache/cayenne/modeler/ui/action/CreateRelationshipAction.java

@@ -86,9 +86,11 @@ public void performAction(ActionEvent e) {
         ObjEntity objEnt = getProjectSession().getSelectedObjEntity();
         if (objEnt != null) {
 
-            new ObjRelationshipInfoDialog(getProjectSession(), app.getFrame())
-                    .createRelationship(objEnt)
-                    .open();
+            if (ObjRelationshipInfoDialog.canMap(objEnt, app.getFrame())) {
+                new ObjRelationshipInfoDialog(getProjectSession(), app.getFrame())
+                        .createRelationship(objEnt)
+                        .open();
+            }
 
         } else {
             DbEntity dbEnt = getProjectSession().getSelectedDbEntity();

modeler/cayenne-modeler/src/main/java/org/apache/cayenne/modeler/ui/project/editor/objentity/properties/ObjRelationshipPanel.java

@@ -377,8 +377,12 @@ private void edit(ActionEvent e) {
         }
 
         ObjRelationshipTableModel model = (ObjRelationshipTableModel) table.getModel();
+        ObjRelationship relationship = model.getRelationship(row);
+        if (!ObjRelationshipInfoDialog.canMap(relationship.getSourceEntity(), app.getFrame())) {
+            return;
+        }
         new ObjRelationshipInfoDialog(session, app.getFrame())
-                .modifyRelationship(model.getRelationship(row))
+                .modifyRelationship(relationship)
                 .open();
 
         // This is required for a table to be updated properly

modeler/cayenne-modeler/src/main/java/org/apache/cayenne/modeler/ui/project/editor/objentity/relinfo/ObjRelationshipInfoDialog.java

@@ -21,7 +21,6 @@
 import com.jgoodies.forms.builder.PanelBuilder;
 import com.jgoodies.forms.layout.CellConstraints;
 import com.jgoodies.forms.layout.FormLayout;
-import org.apache.cayenne.CayenneRuntimeException;
 import org.apache.cayenne.configuration.DataChannelDescriptor;
 import org.apache.cayenne.dbsync.naming.NameBuilder;
 import org.apache.cayenne.map.DbEntity;
@@ -151,10 +150,6 @@ public ObjRelationshipInfoDialog modifyRelationship(ObjRelationship rel) {
         this.relationship = rel;
         this.undo = new ObjRelationshipUndoableEdit(session, rel);
 
-        // current limitation is that an ObjRelationship must have source
-        // and target entities present, with DbEntities chosen.
-        validateCanMap();
-
         initFromModel();
         initBindings();
         return this;
@@ -587,17 +582,28 @@ private void connectEnds() {
     }
 
     /**
-     * Checks if the entity can be edited with this inspector.
+     * Checks whether the given source entity can be mapped with this inspector, showing an
+     * informative message and returning false if not. Callers must use this to decide whether to
+     * open the inspector at all — the dialog assumes a mappable source entity.
      * NOTE: As of CAY-1077, the inspector can be opened even with no target entity set.
      */
-    private void validateCanMap() {
-        if (relationship.getSourceEntity() == null) {
-            throw new CayenneRuntimeException("Can't map relationship without source entity.");
+    public static boolean canMap(ObjEntity source, Window owner) {
+        if (source == null) {
+            showCannotMapMessage(owner, "This relationship has no source ObjEntity, so it can't be mapped.");
+            return false;
         }
-        if (getStartEntity() == null) {
-            JOptionPane.showMessageDialog(this, "Can't map relationship without source DbEntity. Set source DbEntity.");
-            throw new CayenneRuntimeException("Can't map relationship without source DbEntity.");
+        if (source.getDbEntity() == null) {
+            String message = """
+                    "ObjEntity '%s' is not mapped to a DbEntity. Set either DbEntity or super ObjEntity on the \
+                    "ObjEntity" tab before mapping relationships.""".formatted(source.getName());
+            showCannotMapMessage(owner, message);
+            return false;
         }
+        return true;
+    }
+
+    private static void showCannotMapMessage(Window owner, String message) {
+        JOptionPane.showMessageDialog(owner, message, "Can't Map Relationship", JOptionPane.WARNING_MESSAGE);
     }
 
     private DbEntity getStartEntity() {