tracks form changes and warns users before navigation

WebApp/Components/Features/Teams/Edit.razor

@@ -17,6 +17,7 @@
     BackButtonUrl="/teams" />
 
 <EditForm method="post" Model="Team" OnValidSubmit="UpdateTeam" FormName="edit" Enhance>
+        <FormChangeTracker @ref="_formChangeTracker" />
         <AntiforgeryToken />
         <DataAnnotationsValidator/>
         <MudGrid>
@@ -38,7 +39,7 @@
 
 <FormActions>
     <MudButton OnClick="UpdateTeam" Variant="Variant.Filled" Color="Color.Primary">Save</MudButton>
-    <MudButton Href="/teams" Variant="Variant.Text">Cancel</MudButton>
+    <MudButton OnClick="HandleCancel" Variant="Variant.Text">Cancel</MudButton>
 </FormActions>
 
 @code {
@@ -48,6 +49,7 @@
     [SupplyParameterFromForm]
     private Team? Team { get; set; }
 
+    private FormChangeTracker? _formChangeTracker;
     private IEnumerable<Student>? _selectedStudents = [];
     private List<Student> _students = [];
 
@@ -100,6 +102,8 @@
         try
         {
             await Context.SaveChangesAsync();
+            _formChangeTracker?.AllowNavigation();
+            NavigationManager.NavigateTo("/teams");
         }
         catch (DbUpdateConcurrencyException)
         {
@@ -112,7 +116,11 @@
                 throw;
             }
         }
+    }
 
+    private void HandleCancel()
+    {
+        _formChangeTracker?.AllowNavigation();
         NavigationManager.NavigateTo("/teams");
     }