Add Clock page with live DB time and TimeApiClient service

Introduced a new Clock page that displays and updates the current database server time every second by calling a backend API. Added the TimeApiClient service to handle API requests for the server time. Registered TimeApiClient in Program.cs and updated the navigation menu to include a link to the new Clock page. Includes error handling and custom UI styling for the clock display.

DbFirst.API/Controllers/TimeController.cs

@@ -0,0 +1,28 @@
+using DbFirst.Application.Time.Commands;
+using DbFirst.Domain.Entities;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DbFirst.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class TimeController : ControllerBase
+{
+    private readonly IMediator _mediator;
+
+    public TimeController(IMediator mediator)
+    {
+        _mediator = mediator;
+    }
+
+    [HttpPost]
+    public async Task<ActionResult<TimeRecord>> InsertAndGetLast(CancellationToken cancellationToken)
+    {
+        var result = await _mediator.Send(new InsertTimeCommand(), cancellationToken);
+        if (result == null)
+            return NotFound();
+
+        return Ok(result);
+    }
+}

DbFirst.API/Program.cs

@@ -54,6 +54,7 @@ builder.Services.AddApplication();
 builder.Services.AddScoped<ICatalogRepository, CatalogRepository>();
 builder.Services.AddScoped<IMassDataRepository, MassDataRepository>();
 builder.Services.AddScoped<ILayoutRepository, LayoutRepository>();
+builder.Services.AddScoped<ITimeRepository, TimeRepository>();
 
 builder.Services.AddDevExpressControls();
 builder.Services.AddSignalR();

DbFirst.Application/Repositories/ITimeRepository.cs

@@ -0,0 +1,9 @@
+using DbFirst.Domain.Entities;
+
+namespace DbFirst.Application.Repositories;
+
+public interface ITimeRepository
+{
+    Task InsertAsync(CancellationToken cancellationToken = default);
+    Task<TimeRecord?> GetLastAsync(CancellationToken cancellationToken = default);
+}

DbFirst.Application/Time/Commands/InsertTimeCommand.cs

@@ -0,0 +1,6 @@
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public record InsertTimeCommand : IRequest<TimeRecord?>;

DbFirst.Application/Time/Commands/InsertTimeHandler.cs

@@ -0,0 +1,21 @@
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using MediatR;
+
+namespace DbFirst.Application.Time.Commands;
+
+public class InsertTimeHandler : IRequestHandler<InsertTimeCommand, TimeRecord?>
+{
+    private readonly ITimeRepository _repository;
+
+    public InsertTimeHandler(ITimeRepository repository)
+    {
+        _repository = repository;
+    }
+
+    public async Task<TimeRecord?> Handle(InsertTimeCommand request, CancellationToken cancellationToken)
+    {
+        await _repository.InsertAsync(cancellationToken);
+        return await _repository.GetLastAsync(cancellationToken);
+    }
+}

DbFirst.BlazorWebApp/Components/Layout/NavMenu.razor

@@ -31,6 +31,12 @@
                 <span class="bi bi-table-nav-menu" aria-hidden="true"></span> MassData
             </NavLink>
         </div>
+
+        <div class="nav-item px-3">
+            <NavLink class="nav-link" href="clock">
+                <span class="bi bi-clock-nav-menu" aria-hidden="true"></span> Clock
+            </NavLink>
+        </div>
     </nav>
 </div>
 

DbFirst.BlazorWebApp/Components/Pages/Clock.razor

@@ -0,0 +1,100 @@
+@rendermode InteractiveServer
+@page "/clock"
+@inject TimeApiClient TimeApi
+@implements IAsyncDisposable
+
+<PageTitle>Clock</PageTitle>
+
+<h3>DB Server Clock</h3>
+
+<div class="clock-wrapper">
+    <div class="clock-display @(_error != null ? "clock-error" : "")">
+        @if (_dbTime.HasValue)
+        {
+            <span class="clock-time">@_dbTime.Value.ToString("HH:mm:ss")</span>
+            <span class="clock-date">@_dbTime.Value.ToString("dd.MM.yyyy")</span>
+        }
+        else if (_error != null)
+        {
+            <span class="clock-time">--:--:--</span>
+            <span class="clock-date text-danger">@_error</span>
+        }
+        else
+        {
+            <span class="clock-time">...</span>
+        }
+    </div>
+</div>
+
+<style>
+    .clock-wrapper {
+        display: flex;
+        justify-content: center;
+        align-items: center;
+        height: 40vh;
+    }
+
+    .clock-display {
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        background: var(--bs-body-bg, #1e1e2e);
+        border: 2px solid var(--bs-border-color, #444);
+        border-radius: 1rem;
+        padding: 2rem 4rem;
+        box-shadow: 0 4px 24px rgba(0,0,0,0.3);
+    }
+
+    .clock-time {
+        font-size: 5rem;
+        font-weight: 700;
+        font-variant-numeric: tabular-nums;
+        letter-spacing: 0.1em;
+        color: var(--bs-primary, #0d6efd);
+    }
+
+    .clock-date {
+        font-size: 1.4rem;
+        margin-top: 0.5rem;
+        opacity: 0.75;
+    }
+
+    .clock-error .clock-time {
+        color: var(--bs-danger, #dc3545);
+    }
+</style>
+
+@code {
+    private DateTime? _dbTime;
+    private string? _error;
+    private Timer? _timer;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await TickAsync();
+        _timer = new Timer(async _ =>
+        {
+            await TickAsync();
+            await InvokeAsync(StateHasChanged);
+        }, null, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(1));
+    }
+
+    private async Task TickAsync()
+    {
+        try
+        {
+            _dbTime = await TimeApi.InsertAndGetLastAsync();
+            _error = null;
+        }
+        catch (Exception ex)
+        {
+            _error = ex.Message;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_timer != null)
+            await _timer.DisposeAsync();
+    }
+}

DbFirst.BlazorWebApp/Components/Pages/Home.razor

@@ -1,7 +1,43 @@
-@page "/"
+@rendermode InteractiveServer
+
+@page "/"
 
 <PageTitle>Home</PageTitle>
 
-<h1>Hello, world!</h1>
+<h1>Database first</h1>
 
-Welcome to your new app.
+<DxCarousel Width="100%"
+            Height="calc(100vh - 9rem)"
+            Data="@GetCarouselData()"
+            ImageSrcField="Source"
+            ImageAltField="AlternateText"
+            LoopNavigationEnabled="true"
+            SlideShowEnabled="true"
+            SlideShowDelay="3000"
+            PauseSlideShowOnHover="true"
+            ImageSizeMode="CarouselImageSizeMode.FitProportional">
+</DxCarousel>
+
+@code {
+    List<CarouselData> GetCarouselData()
+    {
+        return new List<CarouselData>
+        {
+            new CarouselData("/images/DbFirstBefehl.png", "DbFirstBefehl"),
+            new CarouselData("/images/CQRS - Katalog-Datenfluss.png", "CQRS - Katalog-Datenfluss"),
+            new CarouselData("/images/CQRS - Catalog Create, Update, Delete.png", "CQRS - Catalog Create, Update, Delete"),
+        };
+    }
+
+    public class CarouselData
+    {
+        public string Source { get; set; }
+        public string AlternateText { get; set; }
+
+        public CarouselData(string source, string alt)
+        {
+            Source = source;
+            AlternateText = alt;
+        }
+    }
+}

DbFirst.BlazorWebApp/DbFirst.BlazorWebApp.csproj

@@ -14,4 +14,8 @@
     <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.22" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Folder Include="wwwroot\images\" />
+  </ItemGroup>
+
 </Project>

DbFirst.BlazorWebApp/Program.cs

@@ -31,6 +31,10 @@ if (!string.IsNullOrWhiteSpace(apiBaseUrl))
     {
         client.BaseAddress = new Uri(apiBaseUrl);
     });
+    builder.Services.AddHttpClient<TimeApiClient>(client =>
+    {
+        client.BaseAddress = new Uri(apiBaseUrl);
+    });
 }
 else
 {
@@ -38,6 +42,7 @@ else
     builder.Services.AddHttpClient<DashboardApiClient>();
     builder.Services.AddHttpClient<MassDataApiClient>();
     builder.Services.AddHttpClient<LayoutApiClient>();
+    builder.Services.AddHttpClient<TimeApiClient>();
 }
 
 var app = builder.Build();

DbFirst.BlazorWebApp/Services/TimeApiClient.cs

@@ -0,0 +1,27 @@
+using System.Net.Http.Json;
+
+namespace DbFirst.BlazorWebApp.Services;
+
+public class TimeApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/time";
+
+    public TimeApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<DateTime?> InsertAndGetLastAsync()
+    {
+        var response = await _httpClient.PostAsync(Endpoint, null);
+        response.EnsureSuccessStatusCode();
+        var result = await response.Content.ReadFromJsonAsync<TimeResponse>();
+        return result?.Now;
+    }
+
+    private sealed class TimeResponse
+    {
+        public DateTime? Now { get; set; }
+    }
+}

DbFirst.Domain/Entities/Time.cs

@@ -0,0 +1,6 @@
+namespace DbFirst.Domain.Entities;
+
+public class TimeRecord
+{
+    public DateTime? Now { get; set; }
+}

DbFirst.Infrastructure/ApplicationDbContext.cs

@@ -16,6 +16,7 @@ public partial class ApplicationDbContext : DbContext
 
     public virtual DbSet<VwmyCatalog> VwmyCatalogs { get; set; }
     public virtual DbSet<SmfLayout> SmfLayouts { get; set; }
+    public virtual DbSet<TimeRecord> Times { get; set; }
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
@@ -83,6 +84,16 @@ public partial class ApplicationDbContext : DbContext
                 .HasColumnName("CHANGED_WHEN");
         });
 
+        modelBuilder.Entity<TimeRecord>(entity =>
+        {
+            entity.HasNoKey();
+            entity.ToTable("TIME");
+
+            entity.Property(e => e.Now)
+                .HasColumnType("datetime")
+                .HasColumnName("NOW");
+        });
+
         OnModelCreatingPartial(modelBuilder);
     }
 

DbFirst.Infrastructure/Repositories/TimeRepository.cs

@@ -0,0 +1,28 @@
+using DbFirst.Application.Repositories;
+using DbFirst.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace DbFirst.Infrastructure.Repositories;
+
+public class TimeRepository : ITimeRepository
+{
+    private readonly ApplicationDbContext _db;
+
+    public TimeRepository(ApplicationDbContext db)
+    {
+        _db = db;
+    }
+
+    public async Task InsertAsync(CancellationToken cancellationToken = default)
+    {
+        await _db.Database.ExecuteSqlRawAsync("INSERT INTO [TIME] (NOW) VALUES (GETDATE())", cancellationToken);
+    }
+
+    public async Task<TimeRecord?> GetLastAsync(CancellationToken cancellationToken = default)
+    {
+        return await _db.Times
+            .AsNoTracking()
+            .OrderByDescending(t => t.Now)
+            .FirstOrDefaultAsync(cancellationToken);
+    }
+}