Calling [AlsoNotifyCanExecuteFor] on a Get Only Property for an ICommand

[BinaryAssault]

I have an ICommand that needs a CanExecute attached to it.

The CanExecute is triggered by a get only property that is updated elsewhere using [AlsoNotifyChangeFor(nameof(SomeBool)].

I can't attach [AlsoNotifyCanExecuteFor] to my get only property since it's not a field.

What is the correct way to go about this? I really enjoy the code generators and would like to not have to write out the relay command if I don't have to.

[ObservableProperty]
[AlsoNotifyChangeFor(nameof(SomeBool))]
private string someString;

[AlsoNotifyCanExecuteFor(nameof(SomeFunctionCommand))] // <-- point of failure
public bool SomeBool => someClass.Status;

[ICommand]
private void SomeFunction()
{
    // allowed to do stuff iff SomeBool is true
}

[Sergio0694]

In this case you'd need to just move [AlsoNotifyCanExecuteFor(nameof(SomeFunctionCommand)] over someString. Also, note that you will also need to set CanExecute = nameof(SomeBool) in your command, otherwise it won't actually use the value of that property to decide whether it can be executed 🙂

[BinaryAssault]

Hi @Sergio0694, can you give me an example of

set CanExecute = nameof(SomeBool) in your command

I don't quite understand it. I'm sure I used it wrong

[ICommand]
private void SomeFunction()
{ 
    CanExecute = nameof(SomeBool); // doesn't compile.
    // allowed to do stuff iff SomeBool is true
}

[Sergio0694]

Oh, sorry. It's a property in the command attribute, so it should just be:

[ICommand(CanExecute = nameof(SomeBool))]
private void SomeFunction()
{
    // allowed to do stuff iff SomeBool is true
}

[BinaryAssault]

Ah! I knew it was something simple I was missing. Thank you!!

[BinaryAssault]

I implemented as suggested, and now I get a reflection error.
Removing this line gets rid of the error, but obviously never updates the CanExecute

[AlsoNotifyCanExecuteFor(nameof(SomeFunctionCommand))]

Full example

[ObservableProperty]
[AlsoNotifyChangeFor(nameof(SomeBool))]
[AlsoNotifyCanExecuteFor(nameof(SomeFunctionCommand))]
private string someString;

public bool SomeBool => someClass.Status;

[ICommand(CanExecute=nameof(SomeBool))]
private void SomeFunction()
{
    // allowed to do stuff iff SomeBool is true
}

[Sergio0694]

This discussion was about how to notify a command (which was answered), but it's not the right place to report a bug (or a presumed bug). Could you open a new bug report issue and follow the template to provide all required info (including a minimal repro) so we can look into it? Thank you! 🙂

[BinaryAssault]

Will do, thank you @Sergio0694 !