Clean up types, add null checks, try unsafe casts.

Author: comintern

Rubberduck.Core/UI/CodeExplorer/Commands/AddTemplateCommand.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using Rubberduck.Navigation.CodeExplorer;
 using Rubberduck.Templates;
@@ -28,24 +29,49 @@ public bool CanExecuteForNode(ICodeExplorerNode model)
 
         protected override bool EvaluateCanExecute(object parameter)
         {
-            // TODO this cast needs to be safer.
-            var data = ((string templateName, ICodeExplorerNode model)) parameter;
+            if (parameter is null)
+            {
+                return false;
+            }
+
+            try
+            {
+                // TODO this cast needs to be safer.
+                var data = ((string templateName, ICodeExplorerNode model))parameter;
 
-            return base.EvaluateCanExecute(data.model);
+                return base.EvaluateCanExecute(data.model);
+            }
+            catch (Exception ex)
+            {
+                Logger.Trace(ex);
+                return false;
+            }
         }
 
         protected override void OnExecute(object parameter)
         {
-            // TODO this cast needs to be safer.
-            var data = ((string templateName, ICodeExplorerNode node)) parameter;
-
-            if (string.IsNullOrWhiteSpace(data.templateName) || !(data.node is CodeExplorerItemViewModel model))
+            if (parameter is null)
             {
                 return;
             }
 
-            var moduleText = GetTemplate(data.templateName);
-            AddComponent(model, moduleText);
+            try
+            {
+                // TODO this cast needs to be safer.
+                var data = ((string templateName, ICodeExplorerNode node))parameter;
+
+                if (string.IsNullOrWhiteSpace(data.templateName) || !(data.node is CodeExplorerItemViewModel model))
+                {
+                    return;
+                }
+
+                var moduleText = GetTemplate(data.templateName);
+                AddComponent(model, moduleText);
+            }
+            catch (Exception ex)
+            {
+                Logger.Trace(ex);
+            }
         }
 
         private string GetTemplate(string name)

Rubberduck.Core/UI/Converters/TemplateCommandParameterToTupleConverter.cs

@@ -9,15 +9,15 @@ public class TemplateCommandParameterToTupleConverter : IMultiValueConverter
     {
         public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
         {
-            (string templateName, CodeExplorerItemViewModel model) data = (
+            (string templateName, ICodeExplorerNode model) data = (
                 values[0] as string,
-                values[1] as CodeExplorerItemViewModel);
+                values[1] as ICodeExplorerNode);
             return data;
         }
 
         public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
         {
-            var data = ((string templateName, CodeExplorerItemViewModel model))value;
+            var data = ((string templateName, ICodeExplorerNode model))value;
             return new[] {(object) data.templateName, data.model};
         }
     }