Fix null handling and default value assignments in components (#337)

Adjusted multiple properties and variables to explicitly use null instead of default values, ensuring consistency and clarity in initialization. Added fallback logic for cases where execution details or outputs are unavailable, enhancing application stability.

src/modules/Elsa.Studio.Workflows/Components/WorkflowInstanceViewer/Components/ActivityDetailsTab.razor.cs

@@ -21,14 +21,14 @@ public record ActivityExecutionRecordTableRow(int Number, ActivityExecutionRecor
     [Parameter] public int VisiblePaneHeight { get; set; }
 
     /// The activity to display details for.
-    [Parameter] public JsonObject Activity { get; set; } = default!;
+    [Parameter] public JsonObject Activity { get; set; } = null!;
 
     /// The latest activity execution record. Used for displaying the last state of the activity.
     [Parameter] public ActivityExecutionRecord? LastActivityExecution { get; set; }
 
-    [Inject] private IActivityRegistry ActivityRegistry { get; set; } = default!;
+    [Inject] private IActivityRegistry ActivityRegistry { get; set; } = null!;
 
-    private ActivityExecutionRecord? SelectedItem { get; set; } = default!;
+    private ActivityExecutionRecord? SelectedItem { get; set; } = null!;
 
     private IDictionary<string, DataPanelItem> ActivityInfo { get; set; } = new Dictionary<string, DataPanelItem>();
     private IDictionary<string, DataPanelItem> ActivityData { get; set; } = new Dictionary<string, DataPanelItem>();
@@ -66,9 +66,9 @@ private void CreateDataModels()
         var activityName = activity.GetName();
         var activityType = activity.GetTypeName();
         var execution = LastActivityExecution;
-        var activityVersion = execution?.ActivityTypeVersion;
+        var activityVersion = activity.GetVersion();
         var exception = execution?.Exception;
-        var workflowDefinitionId = activity.GetIsWorkflowDefinitionActivity() ? activity.GetWorkflowDefinitionId() : default;
+        var workflowDefinitionId = activity.GetIsWorkflowDefinitionActivity() ? activity.GetWorkflowDefinitionId() : null;
 
         var activityInfo = new Dictionary<string, DataPanelItem>
         {
@@ -99,11 +99,15 @@ private void CreateDataModels()
             foreach (var outputDescriptor in outputDescriptors)
             {
                 var outputValue = outputs != null
-                    ? outputs.TryGetValue(outputDescriptor.Name, out var value) ? value : default
-                    : default;
+                    ? outputs.TryGetValue(outputDescriptor.Name, out var value) ? value : null
+                    : null;
                 outputData[outputDescriptor.Name] = new(outputValue?.ToString());
             }
         }
+        else
+        {
+            activityInfo["Status"] = new("Not executed");
+        }
 
         var exceptionData = new Dictionary<string, DataPanelItem>();
 
@@ -112,7 +116,7 @@ private void CreateDataModels()
             exceptionData["Message"] = new(exception.Message);
             exceptionData["InnerException"] = new(exception.InnerException != null
                 ? exception.InnerException.Type + ": " + exception.InnerException.Message
-                : default);
+                : null);
             exceptionData["StackTrace"] = new(exception.StackTrace);
         }
 
@@ -123,7 +127,7 @@ private void CreateDataModels()
         {
             foreach (var inputDescriptor in activityDescriptor.Inputs)
             {
-                var inputValue = activityState.TryGetValue(inputDescriptor.Name, out var value) ? value : default;
+                var inputValue = activityState.TryGetValue(inputDescriptor.Name, out var value) ? value : null;
                 activityStateData[inputDescriptor.Name] = new(inputValue?.ToString());
             }
         }
@@ -151,7 +155,7 @@ private void CreateSelectedItemDataModels(ActivityExecutionRecord? record)
 
         var outcomesData = record.Payload?.TryGetValue("Outcomes", out var outcomesValue) == true
             ? new Dictionary<string, string?> { ["Outcomes"] = outcomesValue.ToString()! }
-            : default;
+            : null;
 
         var outputData = new Dictionary<string, string?>();
 

src/modules/Elsa.Studio.Workflows/Components/WorkflowInstanceViewer/Components/WorkflowInstanceDesigner.razor.cs

@@ -267,6 +267,10 @@ private async Task<ICollection<ActivityExecutionRecordSummary>> GetActivityExecu
             var lastRecord = records.Last();
             LastActivityExecution = await ActivityExecutionService.GetAsync(lastRecord.Id);
         }
+        else
+        {
+            LastActivityExecution = null;
+        }
 
         return records;
     }