dispose methods null checks

- trying to prevent null exceptions in case resources have been cleared before dispose event has been called
dnenov · Nov 28, 2023 · f5d5563 · f5d5563
1 parent e43ad53
commit f5d5563
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Showing 10 changed files with 50 additions and 22 deletions.
diff --git a/src/DynamoCoreWpf/ViewModels/PackageManager/PackageManagerSearchViewModel.cs b/src/DynamoCoreWpf/ViewModels/PackageManager/PackageManagerSearchViewModel.cs
@@ -1125,6 +1125,7 @@ internal void AddToSearchResults(PackageManagerSearchElementViewModel element)
 
         internal void ClearSearchResults()
         {
+            if (this.SearchResults == null) return;
             foreach (var ele in this.SearchResults)
             {
                 ele.RequestDownload -= PackageOnExecuted;

diff --git a/src/DynamoCoreWpf/ViewModels/PackageManager/PackageManagerViewModel.cs b/src/DynamoCoreWpf/ViewModels/PackageManager/PackageManagerViewModel.cs
@@ -80,6 +80,8 @@ private void InitializeInstalledPackages()
         /// </summary>
         public void Dispose()
         {
+            if (LocalPackages == null) return;
+
             LocalPackages.CollectionChanged -= LocalPackages_CollectionChanged;
         }
     }

diff --git a/src/DynamoCoreWpf/ViewModels/Search/BrowserItemViewModel.cs b/src/DynamoCoreWpf/ViewModels/Search/BrowserItemViewModel.cs
@@ -77,6 +77,7 @@ internal static BrowserInternalElementViewModel WrapExplicit(BrowserInternalElem
 
         public void Dispose()
         {
+            if (Model == null || Model.Items == null) return; 
             Model.Items.CollectionChanged -= ItemsOnCollectionChanged;
         }
 
@@ -369,15 +370,22 @@ private void SubCategoriesOnCollectionChanged(object sender, NotifyCollectionCha
         /// </summary>
         public override void Dispose()
         {
-            foreach (var category in SubCategories)
-                category.PropertyChanged -= CategoryOnPropertyChanged;
+            if (SubCategories != null)
+            {
+                foreach (var category in SubCategories)
+                    category.PropertyChanged -= CategoryOnPropertyChanged;
+            }
 
-            foreach (var item in Items)
-                item.PropertyChanged -= ItemOnPropertyChanged;
+            if (Items != null)
+            {
+                foreach (var item in Items)
+                    item.PropertyChanged -= ItemOnPropertyChanged;
+                Items.CollectionChanged -= ItemsOnCollectionChanged;    
+            }
+
+            if (Entries != null) Entries.CollectionChanged -= OnCollectionChanged;
+            if (SubCategories != null) SubCategories.CollectionChanged -= SubCategoriesOnCollectionChanged;
 
-            Entries.CollectionChanged -= OnCollectionChanged;
-            SubCategories.CollectionChanged -= SubCategoriesOnCollectionChanged;
-            Items.CollectionChanged -= ItemsOnCollectionChanged;
             base.Dispose();
         }
 
@@ -389,11 +397,17 @@ public void DisposeTree()
         {
             Dispose();
 
-            foreach (var entry in Entries)
-                entry.Dispose();
+            if (Entries != null)
+            {
+                foreach (var entry in Entries)
+                    entry.Dispose();
+            }
 
-            foreach (var subCategory in SubCategories)
-                subCategory.DisposeTree();
+            if (SubCategories != null)
+            {
+                foreach (var subCategory in SubCategories)
+                    subCategory.DisposeTree();
+            }
         }
 
         private void CategoryOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)

diff --git a/src/DynamoCoreWpf/Views/Core/DynamoView.xaml.cs b/src/DynamoCoreWpf/Views/Core/DynamoView.xaml.cs
@@ -2030,6 +2030,7 @@ private void WindowClosed(object sender, EventArgs e)
             this.Dispose();
             sharedViewExtensionLoadedParams?.Dispose();
             this._pkgSearchVM?.Dispose();
+            this._pkgVM?.Dispose();
         }
 
         // the key press event is being intercepted before it can get to

diff --git a/src/DynamoCoreWpf/Views/PackageManager/Controls/PackageManagerPublishControl.xaml.cs b/src/DynamoCoreWpf/Views/PackageManager/Controls/PackageManagerPublishControl.xaml.cs
@@ -62,8 +62,12 @@ public void Dispose()
                 Actions.Close,
                 Categories.PackageManagerOperations);
 
-            PublishPackageViewModel.PublishSuccess -= PackageViewModelOnPublishSuccess;
-            PublishPackageViewModel.RequestShowFolderBrowserDialog -= OnRequestShowFolderBrowserDialog;
+            if(PublishPackageViewModel != null )
+            {
+                PublishPackageViewModel.PublishSuccess -= PackageViewModelOnPublishSuccess;
+                PublishPackageViewModel.RequestShowFolderBrowserDialog -= OnRequestShowFolderBrowserDialog;
+
+            }
 
             this.Loaded -= InitializeContext;
 
@@ -73,7 +77,7 @@ public void Dispose()
             PublishPages = null;
             NavButtonStacks = null;
 
-            Breadcrumbs.Clear();
+            Breadcrumbs?.Clear();
         }
 
         private void InitializePages()
@@ -101,6 +105,8 @@ private void InitializePages()
 
         private void PackageViewModelOnPublishSuccess(PublishPackageViewModel sender)
         {
+            if (PublishPages == null) return;
+
             statusLabel.Visibility = Visibility.Collapsed;
 
             currentPage = 3;
@@ -270,6 +276,8 @@ private void ToggleButtonRowVisibility(int page)
 
         private void DisposePages()
         {
+            if (PublishPages == null || !PublishPages.Any()) return;
+
             foreach(var page in PublishPages.Values)
             {
                 if (page is PublishPackagePublishPage)

diff --git a/src/DynamoCoreWpf/Views/PackageManager/PackageManagerView.xaml.cs b/src/DynamoCoreWpf/Views/PackageManager/PackageManagerView.xaml.cs
@@ -127,8 +127,10 @@ private void CloseButton_Click(object sender, RoutedEventArgs e)
 
         private void WindowClosed(object sender, EventArgs e)
         {
-            this.packageManagerPublish.Dispose();
-            this.packageManagerSearch.Dispose();
+            this.packageManagerPublish?.Dispose();
+            this.packageManagerSearch?.Dispose();
+
+            if (PackageManagerViewModel == null) return;
             this.PackageManagerViewModel.PackageSearchViewModel.RequestShowFileDialog -= OnRequestShowFileDialog;
             this.PackageManagerViewModel.PackageSearchViewModel.PackageManagerViewClose();
             this.PackageManagerViewModel.PublishPackageViewModel.CancelCommand.Execute();

diff --git a/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackagePreviewPage.xaml.cs b/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackagePreviewPage.xaml.cs
@@ -43,7 +43,7 @@ public void Dispose()
         {
             this.PublishPackageViewModel = null;
             this.DataContextChanged -= PublishPackagePublishPage_DataContextChanged;
-            this.customBrowserControl.Dispose();
+            this.customBrowserControl?.Dispose();
         }
 
         private void customBrowserControl_Loaded(object sender, RoutedEventArgs e)

diff --git a/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackagePublishPage.xaml.cs b/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackagePublishPage.xaml.cs
@@ -88,7 +88,7 @@ public void Dispose()
         {
             this.PublishPackageViewModel = null;
             this.DataContextChanged -= PublishPackagePublishPage_DataContextChanged;
-            this.previewBrowserControl.Dispose();
+            this.previewBrowserControl?.Dispose();
         }
 
         private void NavigationButton_Click(object sender, RoutedEventArgs e)

diff --git a/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackageSelectPage.xaml.cs b/src/DynamoCoreWpf/Views/PackageManager/Pages/PublishPackageSelectPage.xaml.cs
@@ -77,10 +77,10 @@ internal void LoadEvents()
 
         public void Dispose()
         {
-            this.ItemSelection.Clear();
+            this.ItemSelection?.Clear();
             this.PublishPackageViewModel = null;
             this.DataContextChanged -= PublishPackagePublishPage_DataContextChanged;
-            this.customBrowserControl.Dispose();
+            this.customBrowserControl?.Dispose();
         }
 
         private void customBrowserControl_Loaded(object sender, RoutedEventArgs e)

diff --git a/src/DynamoPackages/PackageDirectoryBuilder.cs b/src/DynamoPackages/PackageDirectoryBuilder.cs
@@ -57,7 +57,7 @@ public IDirectoryInfo BuildDirectory(Package package, string packagesDirectory,
             WritePackageHeader(package, rootDir);
             RemoveUnselectedFiles(contentFiles, rootDir);
             CopyFilesIntoPackageDirectory(contentFiles, markdownFiles, dyfDir, binDir, extraDir, docDir);
-            RemoveDyfFiles(contentFiles, dyfDir);   // Why do we need to remove the dyf files from the publishing folder?
+            RemoveDyfFiles(contentFiles, dyfDir); 
 
             RemapCustomNodeFilePaths(contentFiles, dyfDir.FullName);
 
@@ -77,7 +77,7 @@ public IDirectoryInfo BuildRetainDirectory(Package package, string packagesDirec
 
             RemoveUnselectedFiles(contentFiles.SelectMany(files => files).ToList(), rootDir);
             CopyFilesIntoRetainedPackageDirectory(contentFiles, markdownFiles, rootDir, out dyfFiles);
-            RemoveRetainDyfFiles(contentFiles.SelectMany(files => files).ToList(), dyfFiles);   // Why do we need to remove the dyf files from the publishing folder?
+            RemoveRetainDyfFiles(contentFiles.SelectMany(files => files).ToList(), dyfFiles);  
 
             RemapRetainCustomNodeFilePaths(contentFiles.SelectMany(files => files).ToList(), dyfFiles);