LEARN HOLONET/Tutorials
TutorialHoloNET 4.x · Holochain 0.7.0 / 0.7.1

A template for every app

You'll learn: how each kind of .NET app calls HoloNET, so you can drop HoloNET into the app you already have. Time: 10 minutes. You need: Up and running in 5 minutes done once. The templates: templates/ · Templates reference.

Every template keeps its HoloNET code in HoloNETDemo.cs and calls HoloNETDemos.HoloNETDemo.RunAsync() from the place that fits the app type. That one call is the only line that differs, so here is each app type's wiring. To add HoloNET to an existing app, copy HoloNETDemo.cs into it, add the package the template's .csproj uses, and make the same call.

Console and background services

csharp
// holonet-console: Program.cs
Console.WriteLine(await HoloNETDemos.HoloNETDemo.RunAsync());
csharp
// holonet-worker: Worker.cs. Runs once when the service starts, then idles.
logger.LogInformation("HoloNET demo:\n{result}", await HoloNETDemos.HoloNETDemo.RunAsync());

Web: Web API, MVC, Razor Pages, Blazor

csharp
// holonet-webapi: GET /holonet
app.MapGet("/holonet", async () => Results.Text(await HoloNETDemos.HoloNETDemo.RunAsync()));
csharp
// holonet-mvc: Controllers/HoloNETController.cs
public async Task<IActionResult> Index() => View((object)await HoloNETDemos.HoloNETDemo.RunAsync());
csharp
// holonet-razor: Pages/HoloNET.cshtml.cs
public async Task OnGetAsync() => Result = await HoloNETDemos.HoloNETDemo.RunAsync();
razor
@* holonet-blazor and holonet-blazorwasm: Pages/HoloNET.razor *@
<button class="btn btn-primary" @onclick="Run">Run the HoloNET demo</button>
<pre>@output</pre>

@code {
    private string output = "";
    private async Task Run() => output = await HoloNETDemos.HoloNETDemo.RunAsync();
}

Blazor WebAssembly runs in the browser, which can't host a conductor, so it connects to one you run (see the templates reference).

Desktop: WPF, WinForms, WinUI, Avalonia

csharp
// holonet-wpf, holonet-winui and holonet-avalonia: a button's click handler
private async void RunButton_Click(object sender, RoutedEventArgs e)
{
    RunButton.IsEnabled = false;
    Output.Text = await HoloNETDemos.HoloNETDemo.RunAsync();
    RunButton.IsEnabled = true;
}
csharp
// holonet-winforms: Form1.cs
runButton.Click += async (s, e) => output.Text = await HoloNETDemos.HoloNETDemo.RunAsync();

HoloNET is async all the way through, so the window stays responsive while Holochain works.

Mobile and cross-platform: MAUI, MAUI Blazor, Uno, Android, iOS

csharp
// holonet-maui: MainPage.xaml.cs
private async void OnRunClicked(object? sender, EventArgs e) => OutputLabel.Text = await HoloNETDemos.HoloNETDemo.RunAsync();
csharp
// holonet-android: MainActivity.cs
button.Click += async (s, e) => output.Text = await HoloNETDemos.HoloNETDemo.RunAsync();
csharp
// holonet-ios: SceneDelegate.cs
button.TouchUpInside += async (s, e) => output.Text = await HoloNETDemos.HoloNETDemo.RunAsync ();

A phone can't run a Holochain conductor, so these apps connect to one on your computer or a server. Set HoloNETDemo.AdminUri to reach it (an Android emulator uses ws://10.0.2.2:7777) and HoloNETDemo.HappPath to where the hApp is on the conductor's computer.

Games: Unity

Create a Unity project, copy in the Assets folder from dotnet new holonet-unity, let NuGetForUnity restore the packages and add the HoloNETBehaviour component:

csharp
// holonet-unity: Assets/HoloNET/HoloNETBehaviour.cs
private async void Run() => output = await HoloNETDemos.HoloNETDemo.RunAsync();

For a multiplayer game, create it with --HoloNET hypernet: players join a zone, send each other messages and get an area of interest (Multiplayer with HyperNET).

What the demo does for each library

--HoloNET What RunAsync() does
api Saves and loads a string and a number, shares a score with every agent, and shows a missing key returning IsSuccess = false instead of throwing.
client Connects to the conductor, installs the hApp, creates an avatar with a zome call, and uninstalls.
orm Saves an Avatar class, loads it back, changes it (HoloNET notices), saves again and deletes it.
hypernet Two players join a zone; one sends a message and the other receives it.

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