Dotnet Browser - custom TFM and workload for .NET 7

An attempt to create a .NET SDK workload that provides the net7.0-browser TFM.

Update

net8.0-browser has now been accepted into .NET! However, we have yet to see any official plans for browser API bindings.

This respository will still exist to provide the Trungnt2910.Browser.dll API bindings for the official net8.0-browser and beyond, but the workloads will not be further maintained.

Features

• Run .NET applications in the browser.
• Multi-target .NET applications and libraries with other platforms, using the browser-specific net7.0-browser TFM.
• Access JavaScript APIs (work in progress)

How to install

.NET SDK 7.0 or later is required, as well as the additional wasm-experimental workload.

Use cake to build this project (on a privileged shell):

dotnet workload install wasm-experimental
dotnet tool restore
dotnet cake build.cake --target=InstallWorkload

How to use in your projects

Simply set your project's TargetFramework to net7.0-browser:

    <TargetFramework>net7.0-browser</TargetFramework>

In the future you might need to replace 7.0 with the .NET version you're using.

Sample project

The repo includes a sample project that multi-targets Windows and Browser WebAssembly.

Built-in classes

The project provides a full binding of the browser's DOM JavaScript API in C#. You can call the implemented classes in a way similar to the code in this example:

using Trungnt2910.Browser.Dom;

// The global "window" object can be accessed using `Window.Instance`
Console.WriteLine(Window.Instance.Location.Href);

// Alternatively, you can use `Document.FromExpression("window.document")`,
// or directly access `Window.Instance.Document`.
// On .NET 7, you can also use `JsObject.FromSystemJSObject(JSHost.GlobalThis)`.
var document = JsObject.FromExpression("window.document").Cast<Document>();

// JavaScript functions can be manually called using `InvokeMember`.
var textNode = document.InvokeMember("createTextNode", "Hello world!");

// Members can be accessed using the indexer syntax similar to JavaScript.
document["body"].InvokeMember("appendChild", textNode);

// Events are supported! Here's how you can use one of them.
document.Paste += (sender, clipboardEvent) =>
{
    var dataTransfer = clipboardEvent.ClipboardData;

    var text = dataTransfer.GetData("text/plain");

    if (!string.IsNullOrEmpty(text))
    {
        Console.WriteLine($"Pasted string: {text}");
    }
    else
    {
        Console.WriteLine("Did not paste any text.");
    }
};

Why?

This project is created mostly for multi-targeting purposes. Imagine the pain of building Uno Platform applications and/or libraries and then managing several different projects, from Bruh.Skia.Gtk, Bruh.Skia.Wpf to Bruh.Wasm. Using this project, a single multi-targeted project can be created:

    <TargetFrameworks>net7.0-gtk;net7.0-browser;net7.0-windows7.0</TargetFrameworks>

What happened to net6.0-browser?

.NET 6 support has been dropped after moving from Uno-based Uno.Foundation.WebAssembly to the official .NET wasm-experimental implementation, as WebAssemblyRuntime functions heavily depend on the new System.Runtime.InteropServices.JavaScript namespace, which is only available on .NET 7 or later versions.

Plans

• Optimize JavaScript interop (minimize usage of eval and string serialization, directly copy TypedArrays to the runtime's memory,...).
• Investigate WASM debugging support.
• Source generators for more .d.ts files, similar to how Xamarin.Android can generate bindings from a .jar (currently the included generator only supports lib.dom.d.ts and is a separate console application).
• Rewrite Trungnt2910.Browser.Generators and make it public.
• Build MAUI on top of this workload. Nah, just kidding, this task is too time-consuming.