Inlined space attribute.

Added new DynamicPortListSettingsAttribute.
Added code that gets the settings attribute to use when creating
dynamic lists.
Added several line breaks to make the code more readable.
Updated several parts of the code to C# 4.0.
Converted some if statements to switches so the code is easier to read
and maintain.
Removed several redundant initialization statements.

Scripts/Editor/NodeEditorGUILayout.cs

@@ -6,6 +6,7 @@ using System.Reflection;
 using UnityEditor;
 using UnityEditorInternal;
 using UnityEngine;
+using XNode;
 
 namespace XNodeEditor {
     /// <summary> xNode-specific version of <see cref="EditorGUILayout"/> </summary>
@@ -44,9 +45,22 @@ namespace XNodeEditor {
                 Rect rect = new Rect();
 
                 float spacePadding = 0;
-                SpaceAttribute spaceAttribute;
+                if (NodeEditorUtilities.GetCachedAttrib(port.node.GetType(), property.name, out SpaceAttribute spaceAttribute))
-                if (NodeEditorUtilities.GetCachedAttrib(port.node.GetType(), property.name, out spaceAttribute)) spacePadding = spaceAttribute.height;
+                    spacePadding = spaceAttribute.height;
 
+                bool dplUseConnectionNames = false;
+                bool dplShowEntryIndexes = false;
+                string dplDefaultEntryName = null;
+                string dplEntryFormat = null;
+                //Get the dynamic list settings attribute if any
+                if (NodeEditorUtilities.GetCachedAttrib(port.node.GetType(), property.name, out Node.DynamicPortListSettingsAttribute dplSettingsAttribute))
+                {
+                    dplUseConnectionNames = dplSettingsAttribute.useConnectionNames;
+                    dplShowEntryIndexes = dplSettingsAttribute.showEntryIndexes;
+                    dplDefaultEntryName = dplSettingsAttribute.defaultEntryName;
+                    dplEntryFormat = dplSettingsAttribute.entryFormat;
+                }
+                
                 // If property is an input, display a regular property field and put a port handle on the left side
                 if (port.direction == XNode.NodePort.IO.Input) {
                     // Get data from [Input] attribute
@@ -69,20 +83,23 @@ namespace XNodeEditor {
 
                     if (dynamicPortList) {
                         Type type = GetType(property);
-                        XNode.Node.ConnectionType connectionType = inputAttribute != null ? inputAttribute.connectionType : XNode.Node.ConnectionType.Multiple;
+                        XNode.Node.ConnectionType connectionType = inputAttribute != null ? 
-                        DynamicPortList(property.name, type, property.serializedObject, port.direction, connectionType);
+                            inputAttribute.connectionType : XNode.Node.ConnectionType.Multiple;
+                        Node.TypeConstraint typeConstraint = inputAttribute.typeConstraint;
+                        DynamicPortList(property.name, type, property.serializedObject, port.direction, connectionType, typeConstraint,
+                            dplUseConnectionNames, dplShowEntryIndexes, dplDefaultEntryName, dplEntryFormat);
                         return;
                     }
                     switch (showBacking) {
                         case XNode.Node.ShowBackingValue.Unconnected:
                             // Display a label if port is connected
-                            if (port.IsConnected) EditorGUILayout.LabelField(label != null ? label : new GUIContent(property.displayName));
+                            if (port.IsConnected) EditorGUILayout.LabelField(label ?? new GUIContent(property.displayName));
                             // Display an editable property field if port is not connected
                             else EditorGUILayout.PropertyField(property, label, includeChildren, GUILayout.MinWidth(30));
                             break;
                         case XNode.Node.ShowBackingValue.Never:
                             // Display a label
-                            EditorGUILayout.LabelField(label != null ? label : new GUIContent(property.displayName));
+                            EditorGUILayout.LabelField(label ?? new GUIContent(property.displayName));
                             break;
                         case XNode.Node.ShowBackingValue.Always:
                             // Display an editable property field
@@ -115,28 +132,34 @@ namespace XNodeEditor {
                     if (dynamicPortList) {
                         Type type = GetType(property);
                         XNode.Node.ConnectionType connectionType = outputAttribute != null ? outputAttribute.connectionType : XNode.Node.ConnectionType.Multiple;
-                        DynamicPortList(property.name, type, property.serializedObject, port.direction, connectionType);
+                        Node.TypeConstraint typeConstraint = outputAttribute.typeConstraint;
+                        DynamicPortList(property.name, type, property.serializedObject, port.direction, connectionType, typeConstraint,
+                            dplUseConnectionNames, dplShowEntryIndexes, dplDefaultEntryName, dplEntryFormat);
                         return;
                     }
                     switch (showBacking) {
                         case XNode.Node.ShowBackingValue.Unconnected:
                             // Display a label if port is connected
-                            if (port.IsConnected) EditorGUILayout.LabelField(label != null ? label : new GUIContent(property.displayName), NodeEditorResources.OutputPort, GUILayout.MinWidth(30));
+                            if (port.IsConnected) EditorGUILayout.LabelField(label ?? new GUIContent(property.displayName),
+                                NodeEditorResources.OutputPort, GUILayout.MinWidth(30));
                             // Display an editable property field if port is not connected
                             else EditorGUILayout.PropertyField(property, label, includeChildren, GUILayout.MinWidth(30));
                             break;
                         case XNode.Node.ShowBackingValue.Never:
                             // Display a label
-                            EditorGUILayout.LabelField(label != null ? label : new GUIContent(property.displayName), NodeEditorResources.OutputPort, GUILayout.MinWidth(30));
+                            EditorGUILayout.LabelField(label ?? new GUIContent(property.displayName),
+                                NodeEditorResources.OutputPort, GUILayout.MinWidth(30));
                             break;
                         case XNode.Node.ShowBackingValue.Always:
                             // Display an editable property field
                             EditorGUILayout.PropertyField(property, label, includeChildren, GUILayout.MinWidth(30));
                             break;
+                        default:
+                            throw new ArgumentOutOfRangeException();
                     }
 
                     rect = GUILayoutUtility.GetLastRect();
-                    rect.position = rect.position + new Vector2(rect.width, spacePadding);
+                    rect.position += new Vector2(rect.width, spacePadding);
                 }
 
                 rect.size = new Vector2(16, 16);
@@ -167,24 +190,33 @@ namespace XNodeEditor {
         public static void PortField(GUIContent label, XNode.NodePort port, params GUILayoutOption[] options) {
             if (port == null) return;
             if (options == null) options = new GUILayoutOption[] { GUILayout.MinWidth(30) };
-            Vector2 position = Vector3.zero;
+            Vector2 position;
-            GUIContent content = label != null ? label : new GUIContent(ObjectNames.NicifyVariableName(port.fieldName));
+            GUIContent content = label ?? new GUIContent(ObjectNames.NicifyVariableName(port.fieldName));
 
-            // If property is an input, display a regular property field and put a port handle on the left side
+            switch (port.direction)
-            if (port.direction == XNode.NodePort.IO.Input) {
+            {
-                // Display a label
+                // If property is an input, display a regular property field and put a port handle on the left side
-                EditorGUILayout.LabelField(content, options);
+                // If property is an output, display a text label and put a port handle on the right side
+                case XNode.NodePort.IO.Input:
+                {
+                    // Display a label
+                    EditorGUILayout.LabelField(content, options);
 
-                Rect rect = GUILayoutUtility.GetLastRect();
+                    Rect rect = GUILayoutUtility.GetLastRect();
-                position = rect.position - new Vector2(16, 0);
+                    position = rect.position - new Vector2(16, 0);
-            }
+                    break;
-            // If property is an output, display a text label and put a port handle on the right side
+                }
-            else if (port.direction == XNode.NodePort.IO.Output) {
+                case XNode.NodePort.IO.Output:
-                // Display a label
+                {
-                EditorGUILayout.LabelField(content, NodeEditorResources.OutputPort, options);
+                    // Display a label
+                    EditorGUILayout.LabelField(content, NodeEditorResources.OutputPort, options);
 
-                Rect rect = GUILayoutUtility.GetLastRect();
+                    Rect rect = GUILayoutUtility.GetLastRect();
-                position = rect.position + new Vector2(rect.width, 0);
+                    position = rect.position + new Vector2(rect.width, 0);
+                    break;
+                }
+                default:
+                    throw new ArgumentOutOfRangeException();
             }
             PortField(position, port);
         }
@@ -208,16 +240,22 @@ namespace XNodeEditor {
         /// <summary> Add a port field to previous layout element. </summary>
         public static void AddPortField(XNode.NodePort port) {
             if (port == null) return;
-            Rect rect = new Rect();
+            Rect rect;
 
-            // If property is an input, display a regular property field and put a port handle on the left side
+            switch (port.direction)
-            if (port.direction == XNode.NodePort.IO.Input) {
+            {
-                rect = GUILayoutUtility.GetLastRect();
+                // If property is an input, display a regular property field and put a port handle on the left side
-                rect.position = rect.position - new Vector2(16, 0);
+                case XNode.NodePort.IO.Input:
-                // If property is an output, display a text label and put a port handle on the right side
+                    rect = GUILayoutUtility.GetLastRect();
-            } else if (port.direction == XNode.NodePort.IO.Output) {
+                    rect.position -= new Vector2(16, 0);
-                rect = GUILayoutUtility.GetLastRect();
+                    // If property is an output, display a text label and put a port handle on the right side
-                rect.position = rect.position + new Vector2(rect.width, 0);
+                    break;
+                case XNode.NodePort.IO.Output:
+                    rect = GUILayoutUtility.GetLastRect();
+                    rect.position += new Vector2(rect.width, 0);
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException();
             }
 
             rect.size = new Vector2(16, 16);
@@ -257,7 +295,7 @@ namespace XNodeEditor {
 
         [Obsolete("Use DynamicPortList instead")]
         public static void InstancePortList(string fieldName, Type type, SerializedObject serializedObject, XNode.NodePort.IO io, XNode.Node.ConnectionType connectionType = XNode.Node.ConnectionType.Multiple, XNode.Node.TypeConstraint typeConstraint = XNode.Node.TypeConstraint.None, Action<ReorderableList> onCreation = null) {
-            DynamicPortList(fieldName, type, serializedObject, io, connectionType, typeConstraint, onCreation);
+            DynamicPortList(fieldName, type, serializedObject, io, connectionType, typeConstraint, false, false, "port", null, onCreation);
         }
 #endregion
 
@@ -265,44 +303,66 @@ namespace XNodeEditor {
         public static bool IsDynamicPortListPort(XNode.NodePort port) {
             string[] parts = port.fieldName.Split(' ');
             if (parts.Length != 2) return false;
-            Dictionary<string, ReorderableList> cache;
+            
-            if (ReorderableListCache.TryGetValue(port.node, out cache)) {
+            return ReorderableListCache.TryGetValue(port.node, out var cache) &&
-                ReorderableList list;
+                   cache.TryGetValue(parts[0], out _);
-                if (cache.TryGetValue(parts[0], out list)) return true;
-            }
-            return false;
         }
 
         /// <summary> Draw an editable list of dynamic ports. Port names are named as "[fieldName] [index]" </summary>
-        /// <param name="fieldName">Supply a list for editable values</param>
+        /// <param name="fieldName">Supply a list for editable values.</param>
-        /// <param name="type">Value type of added dynamic ports</param>
+        /// <param name="type">Value type of added dynamic ports.</param>
-        /// <param name="serializedObject">The serializedObject of the node</param>
+        /// <param name="serializedObject">The serializedObject of the node.</param>
-        /// <param name="connectionType">Connection type of added dynamic ports</param>
+        /// <param name="connectionType">Connection type of added dynamic ports.</param>
-        /// <param name="onCreation">Called on the list on creation. Use this if you want to customize the created ReorderableList</param>
+        /// <param name="typeConstraint">The type constraint to use on the ports.</param>
-        public static void DynamicPortList(string fieldName, Type type, SerializedObject serializedObject, XNode.NodePort.IO io, XNode.Node.ConnectionType connectionType = XNode.Node.ConnectionType.Multiple, XNode.Node.TypeConstraint typeConstraint = XNode.Node.TypeConstraint.None, Action<ReorderableList> onCreation = null) {
+        /// <param name="entryFormat">The format to use for entry name generation. An example format would be:
+        /// {portName} [{index}]
+        ///
+        /// {portName} is replaced by the port name.
+        /// {index} is replaced by the port index.
+        /// </param>
+        /// <param name="onCreation">Called on the list on creation. Use this if you want to customize the created ReorderableList.</param>
+        /// <param name="useConnectionNames">Set to true to use the port connection to generate the item names on the labels.</param>
+        /// <param name="showEntryIndexes">Set to true to show entry indexes on the entry labels.</param>
+        /// <param name="defaultEntryName">Set this to a string to be used to generate the default entry name.</param>
+        public static void DynamicPortList(string fieldName, Type type, SerializedObject serializedObject, XNode.NodePort.IO io, 
+            XNode.Node.ConnectionType connectionType = XNode.Node.ConnectionType.Multiple,
+            XNode.Node.TypeConstraint typeConstraint = XNode.Node.TypeConstraint.None,
+            bool useConnectionNames = false,
+            bool showEntryIndexes = false,
+            string defaultEntryName = null,
+            string entryFormat = null,
+            Action<ReorderableList> onCreation = null) {
             XNode.Node node = serializedObject.targetObject as XNode.Node;
 
+            if (node == null)
+            {
+                Debug.LogWarning($"Can't draw dynamic port list of null node for the field {fieldName}. Skipped.");
+                return;
+            }
             var indexedPorts = node.DynamicPorts.Select(x => {
                 string[] split = x.fieldName.Split(' ');
-                if (split != null && split.Length == 2 && split[0] == fieldName) {
+                
-                    int i = -1;
+                if (split.Length != 2 || split[0] != fieldName) return new {index = -1, port = (XNode.NodePort) null};
-                    if (int.TryParse(split[1], out i)) {
+                
-                        return new { index = i, port = x };
+                return int.TryParse(split[1], out var i) ? 
-                    }
+                    new { index = i, port = x } : 
-                }
+                    new { index = -1, port = (XNode.NodePort) null };
-                return new { index = -1, port = (XNode.NodePort) null };
+                
             }).Where(x => x.port != null);
+            
             List<XNode.NodePort> dynamicPorts = indexedPorts.OrderBy(x => x.index).Select(x => x.port).ToList();
 
             ReorderableList list = null;
-            Dictionary<string, ReorderableList> rlc;
+            if (ReorderableListCache.TryGetValue(serializedObject.targetObject, out var rlc)) {
-            if (ReorderableListCache.TryGetValue(serializedObject.targetObject, out rlc)) {
                 if (!rlc.TryGetValue(fieldName, out list)) list = null;
             }
             // If a ReorderableList isn't cached for this array, do so.
             if (list == null) {
                 SerializedProperty arrayData = serializedObject.FindProperty(fieldName);
-                list = CreateReorderableList(fieldName, dynamicPorts, arrayData, type, serializedObject, io, connectionType, typeConstraint, onCreation);
+                
+                list = CreateReorderableList(fieldName, dynamicPorts, arrayData, type, serializedObject, io, connectionType,
+                    typeConstraint, useConnectionNames, showEntryIndexes, defaultEntryName, entryFormat, onCreation);
+                
                 if (ReorderableListCache.TryGetValue(serializedObject.targetObject, out rlc)) rlc.Add(fieldName, list);
                 else ReorderableListCache.Add(serializedObject.targetObject, new Dictionary<string, ReorderableList>() { { fieldName, list } });
             }
@@ -310,7 +370,21 @@ namespace XNodeEditor {
             list.DoLayoutList();
         }
 
-        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) {
+        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,
+            bool useConnectionNames,
+            bool showEntryIndexes,
+            string defaultEntryName,
+            string entryFormat,
+            Action<ReorderableList> onCreation) {
+            
             bool hasArrayData = arrayData != null && arrayData.isArray;
             XNode.Node node = serializedObject.targetObject as XNode.Node;
             ReorderableList list = new ReorderableList(dynamicPorts, null, true, true, true, true);
@@ -319,6 +393,22 @@ namespace XNodeEditor {
             list.drawElementCallback =
                 (Rect rect, int index, bool isActive, bool isFocused) => {
                     XNode.NodePort port = node.GetPort(fieldName + " " + index);
+
+                    string connectedTo = port != null ? port.fieldName : defaultEntryName;
+                    if (useConnectionNames && port != null && port.IsConnected)
+                    {
+                        connectedTo = port.Connection.node.name;
+                    }
+
+                    //Get the format to render
+                    string format = string.IsNullOrEmpty(entryFormat) ? "{portName} {index}" : entryFormat;
+                    
+                    //Assemble the final name
+                    string finalName =
+                        format
+                            .Replace("{portName}", useConnectionNames ? connectedTo : (port != null ? port.fieldName : defaultEntryName))
+                            .Replace("{index}", showEntryIndexes ? $"{index}" : string.Empty);
+                    
                     if (hasArrayData) {
                         if (arrayData.arraySize <= index) {
                             EditorGUI.LabelField(rect, "Array[" + index + "] data out of range");
@@ -326,12 +416,15 @@ namespace XNodeEditor {
                         }
                         SerializedProperty itemData = arrayData.GetArrayElementAtIndex(index);
                         EditorGUI.PropertyField(rect, itemData, true);
-                    } else EditorGUI.LabelField(rect, port != null ? port.fieldName : "");
+                    } else EditorGUI.LabelField(rect, finalName);
-                    if (port != null) {
+
-                        Vector2 pos = rect.position + (port.IsOutput?new Vector2(rect.width + 6, 0) : new Vector2(-36, 0));
+                    if (port == null) return;
-                        NodeEditorGUILayout.PortField(pos, port);
+                    Vector2 pos = rect.position + (port.IsOutput ? 
-                    }
+                                      new Vector2(rect.width + 6, 0) :
+                                      new Vector2(-36, 0));
+                    NodeEditorGUILayout.PortField(pos, port);
                 };
+            
             list.elementHeightCallback =
                 (int index) => {
                     if (hasArrayData) {
@@ -340,14 +433,17 @@ namespace XNodeEditor {
                         return EditorGUI.GetPropertyHeight(itemData);
                     } else return EditorGUIUtility.singleLineHeight;
                 };
+            
             list.drawHeaderCallback =
                 (Rect rect) => {
                     EditorGUI.LabelField(rect, label);
                 };
+            
             list.onSelectCallback =
                 (ReorderableList rl) => {
                     reorderableListIndex = rl.index;
                 };
+            
             list.onReorderCallback =
                 (ReorderableList rl) => {
 
@@ -382,8 +478,9 @@ namespace XNodeEditor {
                     serializedObject.Update();
 
                     // Move array data if there is any
-                    if (hasArrayData) {
+                    if (hasArrayData)
-                        arrayData.MoveArrayElement(reorderableListIndex, rl.index);
+                    {
+                        arrayData?.MoveArrayElement(reorderableListIndex, rl.index);
                     }
 
                     // Apply changes
@@ -392,6 +489,7 @@ namespace XNodeEditor {
                     NodeEditorWindow.current.Repaint();
                     EditorApplication.delayCall += NodeEditorWindow.current.Repaint;
                 };
+            
             list.onAddCallback =
                 (ReorderableList rl) => {
                     // Add dynamic port postfixed with an index number
@@ -408,18 +506,20 @@ namespace XNodeEditor {
                     }
                     serializedObject.ApplyModifiedProperties();
                 };
+            
             list.onRemoveCallback =
                 (ReorderableList rl) => {
 
                     var indexedPorts = node.DynamicPorts.Select(x => {
                         string[] split = x.fieldName.Split(' ');
-                        if (split != null && split.Length == 2 && split[0] == fieldName) {
+                        
-                            int i = -1;
+                        if (split.Length != 2 || split[0] != fieldName)
-                            if (int.TryParse(split[1], out i)) {
+                            return new {index = -1, port = (XNode.NodePort) null};
-                                return new { index = i, port = x };
+                        
-                            }
+                        return int.TryParse(split[1], out var i) ? 
-                        }
+                            new { index = i, port = x } :
-                        return new { index = -1, port = (XNode.NodePort) null };
+                            new { index = -1, port = (XNode.NodePort) null };
+                        
                     }).Where(x => x.port != null);
                     dynamicPorts = indexedPorts.OrderBy(x => x.index).Select(x => x.port).ToList();
 
@@ -453,7 +553,9 @@ namespace XNodeEditor {
                             Debug.Log(rl.list[0]);
                             return;
                         }
+                        
                         arrayData.DeleteArrayElementAtIndex(index);
+                        
                         // Error handling. If the following happens too often, file a bug report at https://github.com/Siccity/xNode/issues
                         if (dynamicPorts.Count <= arrayData.arraySize) {
                             while (dynamicPorts.Count <= arrayData.arraySize) {
@@ -484,7 +586,8 @@ namespace XNodeEditor {
                 serializedObject.ApplyModifiedProperties();
                 serializedObject.Update();
             }
-            if (onCreation != null) onCreation(list);
+
+            onCreation?.Invoke(list);
             return list;
         }
     }

Scripts/Node.cs

@@ -311,6 +311,33 @@ namespace XNode {
             [Obsolete("Use constructor with TypeConstraint")]
             public OutputAttribute(ShowBackingValue backingValue, ConnectionType connectionType, bool dynamicPortList) : this(backingValue, connectionType, TypeConstraint.None, dynamicPortList) { }
         }
+        
+        /// <summary>
+        /// Use this to specify how a dynamic port list should be configured.
+        /// </summary>
+        [AttributeUsage(AttributeTargets.Field)]
+        public class DynamicPortListSettingsAttribute : Attribute
+        {
+            /// <summary>
+            /// Set this to true to use the first connection name as the name of each entry in the port list.
+            /// </summary>
+            public bool useConnectionNames;
+
+            /// <summary>
+            /// Set to true to show the entry index in the entry name.
+            /// </summary>
+            public bool showEntryIndexes;
+            
+            /// <summary>
+            /// Use this to define the entry name for elements in the list.
+            /// </summary>
+            public string defaultEntryName = null;
+
+            /// <summary>
+            /// The format to use to display the list values.
+            /// </summary>
+            public string entryFormat = null;
+        }
 
         [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
         public class CreateNodeMenuAttribute : Attribute {