Allow ability to raise CanExecuteChanged event of all commands for any property change

[bwood4]

Overview

I've found that I frequently have long lists of commands to update when properties change. It might be nice to be able to flag a class to raise CanExecuteChanged events for all commands whenever any property changes, then you wouldn't have to worry about remembering each command for each dependent property.

I think it would cut down on a decent amount of boilerplate with a fairly minor performance hit from unnecessarily calling CanExecute.

API breakdown

I think the API would just be an attribute you can add to an ObservableObject like this:

[AlwaysNotifyCanExecute]
public partial class ViewModel : ObservableObject
{
...
}

Usage example

[AlwaysNotifyCanExecute]
public partial class ViewModel : ObservableObject
{
    public IRelayCommand DoThing1Command { get; }
    
    [RelayCommand]
    public void DoThing2() { }
}

would generate the following code:

partial class ViewModel
{
    protected overrides void OnPropertyChanged(PropertyChangedEventArgs args)
    {
        base.OnPropertyChanged(args);
        DoThing1Command.NotifyCanExecuteChanged();
        DoThing2Command.NotifyCanExecuteChanged();
    }
}

Breaking change?

No

Alternatives

Edit:

You could also require/allow the attribute to take in the command names that you want to always update, ie:

[AlwaysNotifyCanExecuteChanged(nameOf(DoThing1Command))]
public partial class ViewModel : ObservableObject

or maybe place the attribute on each command or tie it in to the RelayCommandAttribute:

public partial class ViewModel : ObservableObject
{
    [AlwaysNotifyCanExecute]
    public IRelayCommand DoThing1Command { get; }
    
    [RelayCommand(AlwaysNotifyCanExecute = true)]
    public void DoThing2() { }
}

Additional context

Since this is an opt-in feature, there shouldn't be breaking changes and it makes it clear at the top of the class what is happening behind the scenes.

Help us help you

No, just wanted to propose this