Command Event

We can't use UnityEvent in a command because UnityEvent doesn't support cross-scene reference. So instead, we use CommandEvent to achieve the same functionality.

Not only as a replacement, but CommandEvent also have features which UnityEvent does not support. A command event supports public setter properties and methods with up to four parameters, with the following parameter types:

• string
• float
• int
• bool
• Color
• AnimationCurve
• Vector3
• Vector3Int
• Vector2
• Vector2Int
• Vector4
• Rect
• Bounds
• Enum
• UnityEngine.Object and its subclasses
• TargetObject<>

Just like UnityEvent, command event also supports both static and dynamic parameters.

Static Parameters

when declared as CommandEvent without generic arguments, then the event will invoke the callbacks with static parameter(s) that is defined through the command node.

...
public class InvokeEventExampleCommand : Command, ICommandAutoDraw
{
    
    public override float nodeWidth => 350f;

    public CommandEvent myEvent;

    public override void Execute(CommandExecutionFlow _flow)
    {
        myEvent?.Invoke();
        Exit();
    }
}

A built-in Invoke Event command is already available if all that you need is only a simple command that invokes a CommandEvent. However, you will need to create a custom command if you require more advanced conditioning before invoking the event.

Dynamic Parameters

A CommandEvent with dynamic parameters is needed when the parameter can't be pre-defined through the command node, since the value can only be retrieved during runtime.

Similar to UnityEvent, we can also create our own dynamic command event type by declaring a class derived from CommandEvent<>.

[System.Serializable]
[RegisterCommand("Custom/Invoke Int Event", typeof(SequineFlowCommandData))]
public class InvokeIntEventCommand : Command, ICommandAutoDraw
{
    public override float nodeWidth => 350f;

    [System.Serializable]
    public class IntEvent : CommandEvent<int> { }

    public IntEvent myIntEvent;

    public override void Execute(CommandExecutionFlow _flow)
    {
        int randomInt = Random.Range(0, 100);
        myIntEvent?.Invoke(randomInt);
        Exit();
    }

}