Use CommunityToolkit.Mvvm to generate "required" property

Question

I'm using CommunityToolkit.Mvvm in my WPF project.

As usual, I'm declaring only my private backing fields and I'm adding the [ObservableProperty] attribute on them. I'd like some generated properties to be "required", so that when an instance of the class is created, it is mandatory to set these properties. Is there a way to achieve this behaviour from source code generators in CommunityToolkit.Mvvm?

Answer 1

At the time of writing, it isn't released yet¹ but support for [ObservableProperty] on partial properties is on the way. This means, instead of declaring the backing field² you will be able to use the generator with a required partial property as follows:

public partial class Foo : ObservableObject
{
    [ObservableProperty]
    public required partial string Bar { get; set; }
}

Note that partial properties come with C# 13.

_{¹ You can use preview versions by using nuget package sources like https://pkgs.dev.azure.com/dotnet/CommunityToolkit/_packaging/CommunityToolkit-PullRequests/nuget/v3/index.json}

_{² This new version comes with a code analysis rule (MVVMTK0042) that suggests using [ObservableProperty] on partial properties instead of fields and a code fix provider for it so you can do the switch automatically}