State

UNLang State is a state type of state machine, since state machine is a common way to handle a game logic. Using state, user could implement loop logic during a certain time only if the state is not exit.

Of cause, user could implement basic state of their own by override LangNode, but UNLang has provided buildin one for user to customize.

State

UNLang State provides some default LangSpot.

Spot	Description
Begin	The state entrance.
Abort	Force to exit the state.
OnEnter	The state initialize trigger.
OnUpdate	The state frame tick trigger.
OnExit	The state terminate trigger.
Substate	Child state of the state.

How to Use State

There are two ways to use UNLang state.

Let’s use state to print Hello UNLang! per frame.

Use State to trigger other module

Use UNLang State directly and drive other logic.

Use OnUpdate output spot to trigger MyModule created in UNLang Node section since OnUpdate will be triggered per frame.

Extend State

Implement MyStateModule to do the same thing.

using UNLang;
using UNode;

[NodeInterface("MyStateModule", "Script/")]
public sealed class MyStateModule : State
{
    protected override void OnExecute(LangInstance instance)
    {
        UnityEngine.Debug.Log("Hello UNLang!");
    }
}

Override OnExecute protected method to print the constant string.

Difference

The big difference between the two options is whether the logic could be controlled in UNLang. If user wants to control the logic in UNLang, exporting the logic module and use fundamental modules to compose; Or implement the full feature internally and trigger it by UNLang.

Which way to use is mainly based on the complexity and reuse of the logic, and fully decided by user.