Added DisplayValue and GetValue

Example/Nodes/DisplayValue.cs

@@ -0,0 +1,5 @@
+using UnityEngine;
+
+public class DisplayValue : Node {
+    [Input] public float value;
+}

Example/Nodes/DisplayValue.cs.meta

@@ -0,0 +1,12 @@
+fileFormatVersion: 2
+guid: 98f6f901f0da53142b79277ea3f42518
+timeCreated: 1507499149
+licenseType: Free
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Example/Nodes/Editor/DisplayValueEditor.cs

@@ -0,0 +1,32 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEditor;
+
+[CustomNodeEditor(typeof(DisplayValue), "Display Value")]
+public class DisplayValueEditor : NodeEditor {
+
+    public override void OnNodeGUI(out Dictionary<NodePort, Vector2> portPositions) {
+        base.OnNodeGUI(out portPositions);
+        EditorGUILayout.LabelField("Value: " + GetResult());
+    }
+
+    public float GetResult() {
+        float result = 0f;
+        NodePort port = target.GetInputByFieldName("value");
+        if (port == null) return result;
+        int connectionCount = port.ConnectionCount;
+        for (int i = 0; i < connectionCount; i++) {
+
+            NodePort connection = port.GetConnection(i);
+            if (connection == null) continue;
+
+            object obj = connection.GetValue();
+            if (obj == null) continue;
+
+            if (connection.type == typeof(int)) result += (int)obj;
+            else if (connection.type == typeof(float)) result += (float)obj;
+        }
+        return result;
+    }
+}

Example/Nodes/Editor/DisplayValueEditor.cs.meta

@@ -0,0 +1,12 @@
+fileFormatVersion: 2
+guid: 429e0671aa9024e449642837aeadc9c2
+timeCreated: 1507499229
+licenseType: Free
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Example/Nodes/MathNode.cs

@@ -2,8 +2,8 @@
 
 [System.Serializable]
 public class MathNode : Node {
-    [Input] public float a;
+    public float a;
-    [Input] public float b;
+    public float b;
     [Output] public float result;
     public enum MathType { Add, Subtract, Multiply, Divide}
     public MathType mathType = MathType.Add;
@@ -12,6 +12,20 @@ public class MathNode : Node {
         name = "Math";
     }
 
+    public override object GetValue(NodePort port) {
+        switch(port.fieldName) {
+            case "result":
+                switch(mathType) {
+                    case MathType.Add: return a + b;
+                    case MathType.Subtract: return a - b;
+                    case MathType.Multiply: return a * b;
+                    case MathType.Divide: return a / b;
+                }
+                break;
+        }
+        return 0f;
+    }
+
     public override void OnCreateConnection(NodePort from, NodePort to) {
 
     }

Scripts/Editor/NodeEditor.cs

@@ -58,7 +58,6 @@ public class NodeEditor {
             if (NodeEditorUtilities.HasAttrib<Node.InputAttribute>(fieldAttribs) || NodeEditorUtilities.HasAttrib<Node.OutputAttribute>(fieldAttribs)) continue;
             DrawFieldInfoDrawerGUI(fields[i]);
         }
-        EditorGUILayout.Space();
     }
 
     /// <summary> Draw node port GUI using automatic layouting. Returns port handle position. </summary>

Scripts/Editor/NodeEditorGUI.cs

@@ -167,6 +167,8 @@ public partial class NodeEditorWindow {
             //Draw node contents
             Dictionary<NodePort, Vector2> portHandlePoints;
             nodeEditor.OnNodeGUI(out portHandlePoints);
+            EditorGUILayout.Space();
+
             if (e.type == EventType.Repaint) {
                 foreach (var kvp in portHandlePoints) {
                     Vector2 portHandlePos = kvp.Value;

Scripts/Node.cs

@@ -1,6 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using System.Linq;
 using System;
 
 /// <summary> Base class for all nodes </summary>
@@ -13,16 +14,18 @@ public abstract class Node : ScriptableObject {
     /// <summary> Input <see cref="NodePort"/>s. It is recommended not to modify these at hand. Instead, see <see cref="InputAttribute"/> </summary>
     [SerializeField] public List<NodePort> inputs = new List<NodePort>();
     /// <summary> Output <see cref="NodePort"/>s. It is recommended not to modify these at hand. Instead, see <see cref="InputAttribute"/> </summary>
-    [SerializeField] public NodePort[] outputs = new NodePort[0];
+    [SerializeField] public List<NodePort> outputs = new List<NodePort>();
 
     public int InputCount { get { return inputs.Count; } }
-    public int OutputCount { get { return outputs.Length; } }
+    public int OutputCount { get { return outputs.Count; } }
 
     protected Node() {
         CachePorts(); //Cache the ports at creation time so we don't have to use reflection at runtime
     }
 
     protected void OnEnable() {
+        VerifyConnections();
+        CachePorts();
         Init();
     }
 
@@ -49,6 +52,7 @@ public abstract class Node : ScriptableObject {
         for (int i = 0; i < OutputCount; i++) {
             if (outputs[i].fieldName == fieldName) return outputs[i];
         }
+        Debug.LogWarning("No outputs with fieldName '" + fieldName+"'");
         return null;
     }
 
@@ -57,6 +61,12 @@ public abstract class Node : ScriptableObject {
         for (int i = 0; i < InputCount; i++) {
             if (inputs[i].fieldName == fieldName) return inputs[i];
         }
+        Debug.LogWarning("No inputs with fieldName '" + fieldName+"'");
+        return null;
+    }
+
+    public virtual object GetValue(NodePort port) {
+        Debug.LogWarning("No GetValue(NodePort port) override defined for " + GetType());
         return null;
     }
 
@@ -75,7 +85,7 @@ public abstract class Node : ScriptableObject {
         return -1;
     }
     public int GetOutputId(NodePort output) {
-        for (int i = 0; i < outputs.Length; i++) {
+        for (int i = 0; i < outputs.Count; i++) {
             if (output == outputs[i]) return i;
 
         }
@@ -86,7 +96,7 @@ public abstract class Node : ScriptableObject {
         for (int i = 0; i < inputs.Count; i++) {
             inputs[i].ClearConnections();
         }
-        for (int i = 0; i < outputs.Length; i++) {
+        for (int i = 0; i < outputs.Count; i++) {
             outputs[i].ClearConnections();
         }
     }
@@ -114,6 +124,7 @@ public abstract class Node : ScriptableObject {
 
         System.Reflection.FieldInfo[] fieldInfo = GetType().GetFields();
         for (int i = 0; i < fieldInfo.Length; i++) {
+
             //Get InputAttribute and OutputAttribute
             object[] attribs = fieldInfo[i].GetCustomAttributes(false);
             InputAttribute inputAttrib =  null;
@@ -122,12 +133,29 @@ public abstract class Node : ScriptableObject {
                 if (attribs[k] is InputAttribute) inputAttrib = attribs[k] as InputAttribute;
                 else if (attribs[k] is OutputAttribute) outputAttrib = attribs[k] as OutputAttribute;
             }
+
             if (inputAttrib != null && outputAttrib != null) Debug.LogError("Field " + fieldInfo + " cannot be both input and output.");
             else if (inputAttrib != null) inputPorts.Add(new NodePort(fieldInfo[i], this));
             else if (outputAttrib != null) outputPorts.Add(new NodePort(fieldInfo[i], this));
         }
 
-        inputs = inputPorts;
+        //Remove
-        outputs = outputPorts.ToArray();
+        for (int i = inputs.Count-1; i >= 0; i--) {
+            //If input nodeport does not exist, remove it
+            if (!inputPorts.Any(x => inputs[i].fieldName == x.fieldName)) inputs.RemoveAt(i);
+        }
+        for (int i = outputs.Count - 1; i >= 0; i--) {
+            //If output nodeport does not exist, remove it
+            if (!outputPorts.Any(x => outputs[i].fieldName == x.fieldName)) outputs.RemoveAt(i);
+        }
+        //Add
+        for (int i = 0; i < inputPorts.Count; i++) {
+            //If inputports contains a new port, add it
+            if (!inputs.Any(x => x.fieldName == inputPorts[i].fieldName)) inputs.Add(inputPorts[i]);
+        }
+        for (int i = 0; i < outputPorts.Count; i++) {
+            //If inputports contains a new port, add it
+            if (!outputs.Any(x => x.fieldName == outputPorts[i].fieldName)) outputs.Add(outputPorts[i]);
+        }
     }
 }

Scripts/NodePort.cs

@@ -55,6 +55,10 @@ public class NodePort {
         }
     }
 
+    public object GetValue() {
+        return node.GetValue(this);
+    }
+
     /// <summary> Connect this <see cref="NodePort"/> to another </summary>
     /// <param name="port">The <see cref="NodePort"/> to connect to</param>
     public void Connect(NodePort port) {