Button Command Binders

Binding an IRelayCommand to a Button.

ButtonCommandBinder

The main binder connecting a command to Button.onClick.

How it works

On bind it subscribes to Button.onClick → calls command.Execute()
Subscribes to command.CanExecuteChanged → updates the button availability
On unbind it unsubscribes from everything

InteractableMode

Defines the reaction to CanExecute:

Mode	Behaviour
`Interactable`	`button.interactable = canExecute`
`Visible`	`gameObject.SetActive(canExecute)`
`None`	Ignores `CanExecute`
`Custom`	Raises the `CanExecuteChanged(bool)` event for manual handling

Binding modes: OneWay, OneTime.

[ViewModel]
public partial class FormViewModel
{
    [RelayCommand(CanExecute = nameof(CanSubmit))]
    private void Submit() { /* ... */ }

    private bool CanSubmit() => !string.IsNullOrEmpty(Text);
}

Parameterized variants

For commands with parameters the parameters are set in the Inspector:

Binder	Command	Parameters
`ButtonCommandBinder`	`IRelayCommand`	—
`ButtonCommandBinder<T>`	`IRelayCommand<T>`	1 parameter
`ButtonCommandBinder<T1, T2>`	`IRelayCommand<T1, T2>`	2 parameters
`ButtonCommandBinder<T1, T2, T3>`	`IRelayCommand<T1, T2, T3>`	3 parameters
`ButtonCommandBinder<T1, T2, T3, T4>`	`IRelayCommand<T1, T2, T3, T4>`	4 parameters

ButtonCommandBinder also accepts IRelayCommand<bool> and passes it true on click.

The generic variants are abstract for Mono; ready-made single-parameter components: ButtonCommandIntMonoBinder, ButtonCommandFloatMonoBinder, ButtonCommandBoolMonoBinder, ButtonCommandStringMonoBinder, ButtonCommandObjectMonoBinder.

Example: a command with a parameter from Stats

// ViewModel:
[RelayCommand]
private void AddSkillPointTo(Skill skill) { /* ... */ }
// → IRelayCommand<Skill> AddSkillPointToCommand

// Inspector:
// ButtonCommandBinder<Skill> with the parameter Skill.Strength