DotRealDb

A real-time database for AspNetCore Backend which is powered with SignalR.

STILL UNDER-DEVELOPMENT

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Summary

to be added...

Getting Started

Server-Side

• Install NuGet package

• Add following code to your Startup:

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllers().AddDotRealDbEndpoints(); // <-- Add this one after IMvcBuilder.
    //...

    services.AddDotRealDb(); // <-- Add this one.
}

• Go your DbContext which you want to make real-time and inherit from DotRealDbContext. If you're using IdentityDbContext or something else and not able to change your inheritance, you just go ---alternative way--- step to make manual implementation.

public class SampleDbContext : DotRealDbContext // <- Change inheritance
{
    protected SampleDbContext() : base()
    {
    }

    // inject IDotRealChangeTracker and sent it to base.
    public SampleDbContext(DbContextOptions options, IDotRealChangeTracker tracker) : base(options, tracker)
    {
    }

    /* Anything else...*/
}

--- Alternative Way ---

If you're not able to change your DbContext inehritance, just use this way.

1. Inject IDotRealChangeTracker into your DbContext:
2. Override SaveChanges methods, and call TrackAndPublishAsync() method over tracker

public class SampleDbContext : IdentityDbContext  // Can't change this inheritance
{

    private readonly IDotRealChangeTracker tracker;
    protected SampleDbContext() : base()
    {
    }

    // (1) inject IDotRealChangeTracker and set it into a field.
    public SampleDbContext(DbContextOptions options, IDotRealChangeTracker tracker) : base(options)
    {
        this.tracker = tracker;
    }

    /* Anything else...*/

    // (2) Override SaveChanges method and call TrackAndPublish method.
    public override int SaveChanges(bool acceptAllChangesOnSuccess)
    {
        return tracker.TrackAndPublishAfter(this, () => base.SaveChanges(acceptAllChangesOnSuccess)); // <-- Here
    }

    public override async Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default)
    {
        return await tracker.TrackAndPublishAfterAsync(this, () => base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken)); // <-- And here
    }
}

• That's it! Your server-side implementation is ready for your DbContext.

---

Client-Side

Dependency Injection Supported Apps (Blazor, ConsoleApp etc.)

• Go your Configure services or Program.cs for Blazor:

For regular Service Collections:

services.AddDotRealDbClient(opts => opts.ServerBaseUrl = "https://localhost:5001");

For Blazor:

public static async Task Main(string[] args)
{
    var builder = WebAssemblyHostBuilder.CreateDefault(args);
    builder.RootComponents.Add<App>("#app");

    builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

    // Add here for Blazor:
    builder.Services.AddDotRealDbClient(opts => opts.ServerBaseUrl = "https://localhost:5001");

    await builder.Build().RunAsync();
}

• Inject IDotRealChangeHandler into your object or get it from DI Container.

• Create a list with type of your model.

• Start tracking over IDotRealChangeHandler interface.

Plain C#:

public class MyViewModel
{
    private readonly IDotRealChangeHandler changeHandler;

    public MyViewModel(IDotRealChangeHandler changeHandler)
    {
        this.changeHandler = changeHandler;
        StartTracking();
    }

    /* You can use any type of collection but I suggest to use ObservableCollection in here. 
     * Because tracker will add, remove, or update elements in your given list.
     * So you can handle changes manually with CollectionChanged event.
     */
    public ObservableCollection<WeatherForecast> Items { get; set; }
    private async void StartTracking()
    {
        this.Items = await changeHandler.StartTrackingAsync<WeatherForecast>("SampleDbContext");
    }
}

For blazor:

@using DotRealDb.Client
@using System.Collections.ObjectModel;
@inject HttpClient Http
@inject IDotRealChangeHandler ChangeHandler

<h1>Weather forecast</h1>

<p>This component demonstrates fetching data from the server.</p>

<hr />

@if (forecasts == null)
{
    <p><em>Loading...</em></p>
}
else
{
    <table class="table">
        <thead>
            <tr>
                <th>Date</th>
                <th>Temp. (C)</th>
                <th>Temp. (F)</th>
                <th>Summary</th>
            </tr>
        </thead>
        <tbody>
            @foreach (var forecast in forecasts)
            {
                <tr>
                    <td>@forecast.Date.ToShortDateString()</td>
                    <td>@forecast.TemperatureC</td>
                    <td>@forecast.TemperatureF</td>
                    <td>@forecast.Summary</td>
                </tr>
            }
        </tbody>
    </table>
}

@code {
    private ObservableCollection<WeatherForecast> forecasts;

    protected override async Task OnInitializedAsync()
    {
        forecasts = await ChangeHandler.ConnectAndTrackAsync<WeatherForecast>("SampleDbContext");

        // Following code is required to render page after any changes:
        forecasts.CollectionChanged += (_, __) => StateHasChanged();
    }
}

---

Dependency Injection Not-Supported Built-in Apps(Xamarin Forms)

• Add DotRealDb.Client nuget package into your portable layer.

• Go your ViewModel and Create an instance of DotRealChangeHandler.

• Create a list and start to track it.

public class MainPageViewModel : BindableObject
{
    private readonly DotRealChangeHandler changeHandler;
    private IList<WeatherForecast> items;

    public MainPageViewModel()
    {
        changeHandler = new DotRealChangeHandler(new DotRealDbClientOptions
        {
            ServerBaseUrl = "http://10.0.2.2:5000"
        });
        ConnectToRealtimeDb();
    }

    public IList<WeatherForecast> Items { get => items; set { items = value; OnPropertyChanged(); } }

    private async void ConnectToRealtimeDb()
    {
        this.Items = await changeHandler.ConnectAndTrackAsync<WeatherForecast>("SampleDbContext");
    }
}