Provide IsNotBusy() method or IsNotBusy readonly property with a new attribute [DependsOnProperty(nameof(IsBusy))]

[suugbut]

In my opinion ObservableProperty (as a publisher) should not know anything about ICommand or other properties (as a subscriber). So the following

public partial class PersonViewModel : ObservableObject
{
    [ObservableProperty]
    [NotifyCanExecuteChangedFor(nameof(SaveCommand))]
    [NotifyPropertyChangedFor(nameof(IsNotBusy))]
    private boo isBusy;

    [RelayCommand(CanExecute = nameof(IsNotBusy))]
    private void Save() { }
    
    private bool IsNotBusy => !IsBusy; // it can be a method too
}

is more elegant if it can be simplified as follows.

public partial class PersonViewModel : ObservableObject
{
    [ObservableProperty]
    private bool isBusy;

    [RelayCommand(CanExecute = nameof(IsNotBusy))]
    private void Save() { }
    
    [DependsOnProperty(nameof(IsBusy))] // <======= the requested attribute.
    private bool IsNotBusy => !IsBusy;
}

When SaveCommand depends on IsNotBusy that depends on IsBusy, it is enough to only decorate IsNotBusy with DependsOnProperty(nameof(IsBusy)).

Interestingly DependsOnProperty lets CanSave(), for example, depend on property IsBusy defined in the base class BaseViewModel.

public partial class BaseViewModel : ObservableObject
{
    [ObservableProperty]
    private bool isBusy;
}
public partial class PersonViewModel : BaseViewModel
{
    [ObservableProperty]
    private bool isDeleted;

    [RelayCommand(CanExecute = nameof(CanSave))]
    private void Save() { }
    
    [DependsOnProperty(nameof(IsBusy))] // <======= the requested attribute.
    [DependsOnProperty(nameof(IsDeleted))] // <======= the requested attribute.
    private bool CanSave => !IsBusy && !IsDeleted;
}

Any comments are welcome.

[hawkerm]

Duplicate of #377 and #367.

A [DependsOn] was already discussed in the past, this comment touches on it here: #367 (comment); these parts in particular are relevant:

It'd introduce a different way to do exactly the same, which adds further confusion.
It breaks the established pattern of generators immediately affecting annotating code, not indirectly.
It makes the generators less efficient, as they'd now have to have extra logic to look at all annotated properties.