Removed unneeded code, clarified that this applies to ports in dynamic lists, and proper verification for dynamic list ports is now in place.

Scripts/Editor/NodeEditorGUILayout.cs

@@ -312,6 +312,8 @@ namespace XNodeEditor {
             }).Where(x => x.port != null);
             List<XNode.NodePort> dynamicPorts = indexedPorts.OrderBy(x => x.index).Select(x => x.port).ToList();
 
+            node.UpdatePorts();
+            
             ReorderableList list = null;
             Dictionary<string, ReorderableList> rlc;
             if (reorderableListCache.TryGetValue(serializedObject.targetObject, out rlc)) {
@@ -327,7 +329,6 @@ namespace XNodeEditor {
             list.list = dynamicPorts;
             list.DoLayoutList();
             
-            node.UpdatePorts();
         }
 
         private static ReorderableList CreateReorderableList(string fieldName, List<XNode.NodePort> dynamicPorts, SerializedProperty arrayData, Type type, SerializedObject serializedObject, XNode.NodePort.IO io, XNode.Node.ConnectionType connectionType, XNode.Node.TypeConstraint typeConstraint, Action<ReorderableList> onCreation) {

Scripts/Node.cs

@@ -123,7 +123,7 @@ namespace XNode {
             Init();
         }
 
-        /// <summary> Update all ports to reflect class fields. This happens automatically on enable or on redrawing the list of ports. </summary>
+        /// <summary> Update static ports and dynamic ports managed by DynamicPortLists to reflect class fields. This happens automatically on enable or on redrawing a dynamic port list. </summary>
         public void UpdatePorts() {
             NodeDataCache.UpdatePorts(this, ports);
         }

Scripts/NodeDataCache.cs

@@ -1,7 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using UnityEditor;
 using UnityEngine;
 
 namespace XNode {
@@ -10,7 +9,7 @@ namespace XNode {
         private static PortDataCache portDataCache;
         private static bool Initialized { get { return portDataCache != null; } }
 
-        /// <summary> Update static and dynamic ports to reflect class fields. </summary>
+        /// <summary> Update static and dynamic ports managed by DynamicPortLists to reflect class fields. </summary>
         public static void UpdatePorts(Node node, Dictionary<string, NodePort> ports) {
             if (!Initialized) BuildCache();
 
@@ -18,7 +17,7 @@ namespace XNode {
             Dictionary<string, List<NodePort>> removedPorts = new Dictionary<string, List<NodePort>>();
             System.Type nodeType = node.GetType();
 
-            List<NodePort> dynamicPorts = new List<NodePort>();
+            List<NodePort> dynamicListPorts = new List<NodePort>();
 
             List<NodePort> typePortCache;
             if (portDataCache.TryGetValue(nodeType, out typePortCache)) {
@@ -28,7 +27,7 @@ namespace XNode {
             }
 
             // Cleanup port dict - Remove nonexisting static ports - update static port types
-            // AND update dynamic ports too!
+            // AND update dynamic ports (albeit only those in lists) too, in order to enforce proper serialisation.
             // Loop through current node ports
             foreach (NodePort port in ports.Values.ToList()) {
                 // If port still exists, check it it has been changed
@@ -47,9 +46,9 @@ namespace XNode {
                     port.ClearConnections();
                     ports.Remove(port.fieldName);
                 }
-                // If the port is dynamic, flag it for reference updates
+                // If the port is dynamic and is managed by a dynamic port list, flag it for reference updates
-                else {
+                else if (IsDynamicListPort(port)) {
-                    dynamicPorts.Add(port);
+                    dynamicListPorts.Add(port);
                 }
             }
             // Add missing ports
@@ -69,30 +68,39 @@ namespace XNode {
                 }
             }
             
-            // Finally, make sure dynamic port settings correspond to the settings of their backing field
+            // Finally, make sure dynamic list port settings correspond to the settings of their "backing port"
-            foreach (NodePort dynamicPort in dynamicPorts) {
+            foreach (NodePort listPort in dynamicListPorts) {
-                string[] parts = dynamicPort.fieldName.Split(' ');
+                // At this point we know that ports here are dynamic list ports
-                if (parts.Length != 2) {
+                // which have passed name/"backing port" checks, ergo we can proceed more safely.
-                    Debug.LogError("Dynamic port name " + dynamicPort.fieldName + " is invalid.");
+                string backingPortName = listPort.fieldName.Split(' ')[0];
-                    continue;
+                NodePort backingPort = staticPorts[backingPortName];
-                }
-                string backingPortName = parts[0];
-                NodePort backingPort;
-                if (!staticPorts.TryGetValue(backingPortName, out backingPort)) {
-                    Debug.LogError($"Could not find backing port \"{backingPortName}\" for port {dynamicPort.fieldName}");
-                    continue;
-                }
                 
                 // Update port constraints. Creating a new port instead will break the editor, mandating the need for setters.
-                dynamicPort.ValueType = backingPort.ValueType;
+                listPort.ValueType = backingPort.ValueType;
-                dynamicPort.direction = backingPort.direction;
+                listPort.direction = backingPort.direction;
-                dynamicPort.connectionType = backingPort.connectionType;
+                listPort.connectionType = backingPort.connectionType;
-                dynamicPort.typeConstraint = backingPort.typeConstraint;
+                listPort.typeConstraint = backingPort.typeConstraint;
-
             }
+        }
 
+        /// <summary>Returns true if the given port is in a dynamic port list.</summary>
+        private static bool IsDynamicListPort(NodePort port) {
+            // Ports flagged as "dynamicPortList = true" end up having a "backing port" and a name with an index, but we have
+            // no guarantee that a dynamic port called "output 0" is an element in a list backed by a static "output" port.
+            // Thus, we need to check for attributes... (but at least we don't need to look at all fields this time)
+            string[] fieldNameParts = port.fieldName.Split(' ');
+            if (fieldNameParts.Length != 2) return false;
             
+            FieldInfo backingPortInfo = port.node.GetType().GetField(fieldNameParts[0]);
+            if (backingPortInfo == null) return false;
             
+            object[] attribs = backingPortInfo.GetCustomAttributes(true);
+            return attribs.Any(x => {
+                Node.InputAttribute inputAttribute = x as Node.InputAttribute;
+                Node.OutputAttribute outputAttribute = x as Node.OutputAttribute;
+                return inputAttribute != null && inputAttribute.dynamicPortList ||
+                       outputAttribute != null && outputAttribute.dynamicPortList;
+            });
         }
         
         /// <summary> Cache node types </summary>
@@ -183,10 +191,5 @@ namespace XNode {
                     this.Add(keys[i], values[i]);
             }
         }
-
-        [MenuItem("TOOLS/LOL")]
-        public static void LOL() {
-            portDataCache = null;
-        }
     }
 }

Scripts/NodePort.cs

@@ -19,10 +19,6 @@ namespace XNode {
             }
         }
 
-        // public IO direction { get { return _direction; } }
-        // public Node.ConnectionType connectionType { get { return _connectionType; } }
-        // public Node.TypeConstraint typeConstraint { get { return _typeConstraint; } }
-
         public IO direction { 
             get { return _direction; }
             internal set { _direction = value; }