commit changes

Author: reddyashish

src/DynamoCore/Graph/Connectors/ConnectorModel.cs

@@ -240,14 +240,9 @@ private void Connect(PortModel p)
         /// </summary>
         internal void Delete()
         {
-            if (Start != null && Start.Connectors.Contains(this))
-            {
-                Start.Connectors.Remove(this);
-            }
-            if (End != null && End.Connectors.Contains(this))
-            {
-                End.Connectors.Remove(this);
-            }
+            Start?.Connectors.Remove(this);
+            End?.Connectors.Remove(this);
+
             OnDeleted();
         }
 

src/DynamoCore/Graph/ModelBase.cs

@@ -233,6 +233,11 @@ public virtual Guid GUID
             }
         }
 
+        /// <summary>
+        /// Has this <see cref="ModelBase"/> been disposed? Gets set when <see cref="Dispose"/> is called.
+        /// </summary>
+        protected bool HasBeenDisposed { get; private set; }
+
         /// <summary>
         /// Protected constructor.
         /// </summary>
@@ -286,7 +291,11 @@ public void SetSize(double w, double h)
         /// </summary>
         public virtual void Dispose()
         {
-            Disposed?.Invoke(this);
+            if (!HasBeenDisposed)
+            {
+                HasBeenDisposed = true;
+                Disposed?.Invoke(this);
+            }
         }
 
         /// <summary>

src/DynamoCore/Graph/Nodes/NodeModel.cs

@@ -1348,6 +1348,21 @@ protected NodeModel()
             OutPorts.CollectionChanged += PortsCollectionChanged;
         }
 
+        private void DisposePort(PortModel portModel, bool nodeDisposing = false)
+        {
+            portModel.PropertyChanged -= OnPortPropertyChanged;
+            portModel.ConnectorCollectionChanged -= ConnectorsCollectionChanged;
+
+            // if this node is being disposed, we don't need to set node state and destroy the connectors,
+            // as the connectors will be deleted elsewhere
+            if (!nodeDisposing)
+            {
+                portModel.DestroyConnectors();
+                SetNodeStateBasedOnConnectionAndDefaults();
+            }
+            portModel.Dispose();
+        }
+
         private void PortsCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
         {
             switch (e.Action)
@@ -1356,25 +1371,15 @@ private void PortsCollectionChanged(object sender, System.Collections.Specialize
                     ConfigureSnapEdges(sender == InPorts ? InPorts : OutPorts);
                     foreach (PortModel p in e.NewItems)
                     {
-                        p.Connectors.CollectionChanged += (coll, args) =>
-                        {
-                            // Call the collection changed handler, replacing
-                            // the 'sender' with the port, which is required
-                            // for the disconnect operations.
-                            ConnectorsCollectionChanged(p, args);
-                        };
                         p.PropertyChanged += OnPortPropertyChanged;
+                        p.ConnectorCollectionChanged += ConnectorsCollectionChanged;
                         SetNodeStateBasedOnConnectionAndDefaults();
                     }
                     break;
                 case System.Collections.Specialized.NotifyCollectionChangedAction.Remove:
                     foreach (PortModel p in e.OldItems)
                     {
-                        p.PropertyChanged -= OnPortPropertyChanged;
-
-                        p.DestroyConnectors();
-
-                        SetNodeStateBasedOnConnectionAndDefaults();
+                        DisposePort(p);
                     }
                     break;
             }
@@ -2929,6 +2934,26 @@ private void OnRenderPackagesUpdated(RenderPackageCache packages)
                 RenderPackagesUpdated(this, packages);
             }
         }
+
+
+        public override void Dispose()
+        {
+            if (HasBeenDisposed) return;
+
+            base.Dispose();
+
+            InPorts.CollectionChanged -= PortsCollectionChanged;
+            foreach(var port in InPorts)
+            {
+                DisposePort(port, nodeDisposing: true);
+            }
+
+            OutPorts.CollectionChanged -= PortsCollectionChanged;
+            foreach(var port in OutPorts)
+            {
+                DisposePort(port, nodeDisposing: true);
+            }
+        }
     }
 
     /// <summary>

src/DynamoCore/Graph/Nodes/PortModel.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.ObjectModel;
+using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Linq;
 using System.Reflection;
@@ -362,6 +363,8 @@ internal PortModel(string name, string toolTip)
             Height = Math.Abs(Height) < 0.001 ? Configurations.PortHeightInPixels : Height;
         }
 
+        internal event NotifyCollectionChangedEventHandler ConnectorCollectionChanged;
+
         /// <summary>
         /// Creates PortModel.
         /// </summary>
@@ -385,6 +388,12 @@ public PortModel(PortType portType, NodeModel owner, PortData data)
 
             MarginThickness = new Thickness(0);
             Height = Math.Abs(data.Height) < 0.001 ? Configurations.PortHeightInPixels : data.Height;
+            Connectors.CollectionChanged += Connectors_CollectionChanged;
+        }
+
+        private void Connectors_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+        {
+            ConnectorCollectionChanged?.Invoke(this, e);
         }
 
         internal void RaisePortIsConnectedChanged()
@@ -400,10 +409,9 @@ internal void DestroyConnectors()
             if (Owner == null)
                 return;
 
-            while (Connectors.Any())
+            for (int i = Connectors.Count - 1; i >= 0; i--)
             {
-                ConnectorModel connector = Connectors[0];
-                connector.Delete();
+                Connectors[i].Delete();
             }
         }
 
@@ -550,6 +558,14 @@ internal string GetOutPortType()
 
             return null;
         }
+
+        public override void Dispose()
+        {
+            if (HasBeenDisposed) return;
+
+            base.Dispose();
+            Connectors.CollectionChanged -= Connectors_CollectionChanged;
+        }
     }
 
     /// <summary>

src/DynamoCore/Graph/Workspaces/WorkspaceModel.cs

@@ -1521,12 +1521,16 @@ public virtual void Clear()
             // have invalid inputs, so these executions are meaningless and may
             // cause invalid GC. See comments in MAGN-7229.
             foreach (NodeModel node in Nodes)
+            {
                 node.RaisesModificationEvents = false;
+                // Dispose here so that all nodes stop listening to disconnect events before
+                // the connectors are deleted. Otherwise remaining undisposed nodes will react
+                // to delete events when an input connector is deleted.
+                node.Dispose();
+            }
 
             foreach (NodeModel el in Nodes)
             {
-                el.Dispose();
-
                 foreach (PortModel p in el.InPorts)
                 {
                     for (int i = p.Connectors.Count - 1; i >= 0; i--)

src/DynamoCore/PublicAPI.Unshipped.txt

@@ -763,6 +763,7 @@ Dynamo.Graph.ModelBase.CenterY.set -> void
 Dynamo.Graph.ModelBase.DeletionStarted -> System.EventHandler<System.ComponentModel.CancelEventArgs>
 Dynamo.Graph.ModelBase.Deserialize(System.Xml.XmlElement element, Dynamo.Graph.SaveContext context) -> void
 Dynamo.Graph.ModelBase.Disposed -> System.Action<Dynamo.Graph.ModelBase>
+Dynamo.Graph.ModelBase.HasBeenDisposed.get -> bool
 Dynamo.Graph.ModelBase.IsSelected.get -> bool
 Dynamo.Graph.ModelBase.IsSelected.set -> void
 Dynamo.Graph.ModelBase.Log(Dynamo.Logging.ILogMessage obj) -> void