Fix: Correct the submission of new school subjects

WorkManagementTool/Components/SchoolSubject/SchoolSubjectCreation.razor

@@ -1,48 +1,53 @@
 @page "/school-subjects/creation"
 
+@rendermode InteractiveServer
+
 @attribute [Authorize]
 @using Microsoft.AspNetCore.Authorization
 @using WorkManagementTool.Services
 @using WorkManagementTool.Data.Entities;
 @inject SchoolSubjectService SchoolSubjectService
 @inject NavigationManager NavigationManager
+@inject ILogger<SchoolSubjectCreation> Logger
 
 <h3>SchoolSubjectCreation</h3>
 
-<EditForm Model="@Model" OnValidSubmit="Submit" FormName="school-subject-creation">
+@if (!string.IsNullOrEmpty(errorMessage))
+{
+    <div class="alert alert-danger">@errorMessage</div>
+}
+
+<EditForm Model="@Model"
+          OnValidSubmit="Submit"
+          FormName="school-subject-creation">
     <ValidationSummary />
     <DataAnnotationsValidator />
 
     <div class="form-group">
         <label for="name" class="form-label">Name</label>
-        <InputText class="form-control" @bind-value="Model!.Name" />
+        <InputText id="name" class="form-control" @bind-Value="Model!.Name" />
+        <ValidationMessage For="@(() => Model!.Name)" />
     </div>
     <div class="form-group">
         <label for="description" class="form-label">Description</label>
-        <InputTextArea class="form-control" @bind-value="Model!.Description"></InputTextArea>
+        <InputTextArea id="description" class="form-control" @bind-Value="Model!.Description"></InputTextArea>
+        <ValidationMessage For="@(() => Model!.Description)" />
     </div>
     <button type="submit" class="btn btn-primary">Create School Subject</button>
 </EditForm>
 
 @code {
-    [SupplyParameterFromForm]
-    private SchoolSubject? Model { get; set; }
+    private SchoolSubject Model { get; set; } = new();
 
-    protected override void OnInitialized()
-    {
-        if (Model is null) 
-        {
-            Model = new SchoolSubject
-            {
-                Name = null!,
-                Description = null,
-            };
-        }
-    }
+    private string? errorMessage;
 
     private async Task Submit()
     {
-        await SchoolSubjectService.AddSchoolSubjectAsync(Model!);
-        NavigationManager.NavigateTo("/school-subjects");
+        if (Model is not null)
+        {
+            await SchoolSubjectService.AddSchoolSubjectAsync(Model);
+            Logger.LogInformation("SchoolSubject created: {Name}", Model.Name);
+            NavigationManager.NavigateTo("/school-subjects");
+        }
     }
-}
+}