Example of the Stateless Scene pattern (see https://corepox.net/devlog/unity-pattern:-stateless-scenes)

async.cs

void loadMyScene(MySceneParams params, System.Action<MySceneOutcome> callback)

MySceneBehaviour.cs

using UnityEngine;
public class MySceneBehaviour: MonoBehaviour {
    private static MySceneParams loadSceneRegister = null;
    
    public MySceneParams sceneParams;

    public static void loadMyScene(MySceneParams sceneParams, System.Action<MySceneOutcome> callback) {
        MySceneBehaviour.loadSceneRegister = sceneParams;
        sceneParams.callback = callback;
        UnityEngine.SceneManagement.SceneManager.LoadScene("MyScene");
    }

    public void Awake() {
        if (loadSceneRegister != null) sceneParams = loadSceneRegister;
        loadSceneRegister = null; // the register has served its purpose, clear the state
    }

    public void endScene (MySceneOutcome outcome) {
        if (sceneParams.callback != null) sceneParams.callback(outcome);
        sceneParams.callback = null; // Protect against double calling;
    }
}

[System.Serializable]
public class MySceneParams {
    public System.Action<MySceneOutcome> callback;
    // + inputs of the scene 
}

public class MySceneOutcome {
    // + outputs of the scene 
}

MySceneBehaviourTest.cs

  void testMyScene() {
      MySceneBehaviour.loadMyScene(new MySceneParams(/* ... */), (outcome) => {
          Debug.Log("Scene over " + outcome.ToString());
      });
  }
    

I read "a functional approach" and I got excited. I'm very new to Unity and just use it for fun. But in my day job I do a lot of functional coding, so I find it odd that I can't (for example) pass any context (other than a starting position and parent) to objects that I create with Instantiate.

So far I've been going with the static-singleton approach but started looking at representing everything as addressables instead, and global state became problematic immediately. I don't even like global state, so this might be a worthy alternative. I will give it a try.

Cool. It's not perfect but it makes more sense to me and it definitely composes better in practice

…

On Thu, Mar 12, 2020, 1:16 AM Timothy Klopotoski ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ I read "a functional approach" <https://gamedev.stackexchange.com/a/178564> and I got excited. I'm very new to Unity and just use it for fun. But in my day job I do a lot of functional coding, so I find it odd that I can't (for example) pass any context (other than a starting position and parent) to objects that I create with Instantiate. So far I've been going with the static-singleton approach <https://gamedev.stackexchange.com/a/110963> but started looking at representing everything as addressables instead, and global state became problematic immediately. I don't even *like* global state, so this might be a worthy alternative. I will give it a try. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <https://gist.github.com/11e0d99f69761ca5dd248e67fd398faf#gistcomment-3208848>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAODGYROKUTZE65RWK4LDYLRHASVTANCNFSM4LGBJLTQ> .

I am using this and helped me a lot with data avoiding globals. I implement an history of previous loaded scenes over this . I wonder if it works to pass existing GameObjects. The only way I found is calling DontDestroyOnLoad but that way makes global anyway except that reference them is easier.