System

useful to coordinate whole gameplay.

Persistence

Persistence allow to persist values on game saves.

enum Case {
  On,
  Off,
}

public class State {
  // do not forget to also set persistence on inner fields
  public persistent let name: CName;
  public persistent let id: TweakDBID;
  public persistent let other: Float;
  // otherwise it won't get persisted
  public let temporary: Bool;
}

public class System extends ScriptableSystem {
  private persistent let count: Int32; // any primitive
  private persistent let case: Case; // including enums
  private persistent let state: ref<State>; // including nested objects
  private persistent let formerStates: array<ref<State>>; // including arrays
  // but
  // no inkHashMap (or similar)
  // no String
  // no Variant
  // no ResRef
}

Requests

Requests are systems' asynchronous mechanism. It's more often than not used to convey an action.

⚠️ be careful that there can only be up to ~128 system requests game-wide, so prefer DelayCallback whenever possible.

credits to psiberx and jekky on discord for finding out about this limitation in memory.

Delayed requests

Requests can also be delayed asynchronously.

Redscript

public class DoSomethingRequest extends ScriptableSystemRequest {
  public let parameter: Float;
}

public class System extends ScriptableSystem {
  private func DoSomething() -> Void {
    let request: ref<DoSomethingRequest>;
    request.parameter = 1.;
    let delay = 3.; // in seconds, real time
    GameInstance
      .GetDelaySystem(this.GetGameInstance())
      .DelayScriptableSystemRequest(this.GetClassName(), request, delay, true);
      // will automatically call OnDoSomethingRequest on System 3 seconds after
  }

  // function signature matters !
  protected final func OnDoSomethingRequest(request: ref<DoSomethingRequest>) -> Void {
    // do something ..
  }
}

Regular requests

Requests can be queued directly on a system.