# DelaySystem and DelayCallback

[DelaySystem](https://nativedb.red4ext.com/DelaySystem) is a class that allows async call of [DelayCallback](https://nativedb.red4ext.com/DelayCallback) after the set amount of time has passed.

This is how to create a custom `DelayCallback`:

```swift
public class CustomCallback extends DelayCallback {
  // all the data that your Call function needs
  private let myInt: Int32;

  public func Call() {
    // custom function that i want to be called when the specified time has passed
    if this.myInt > 1 {
      FTLog("Input is bigger than 1");
    } else {
      FTLog("Input is smaller than 1");
    }
  }

  public static func Create(inputInt: Int32) -> ref<CustomCallback> {
    // use this way to create your Callback class in one line
    let self = new CustomCallback();

    self.myInt = inputInt;
    return self;
  }
}
```

and this is how you can use the `DelaySystem` to call the `Callback` function with a delay:

```swift
let delaySystem = GameInstance.GetDelaySystem(GetGameInstance());
let inputInt: Int32 = 2;
let delay: Float = 1.0;
let isAffectedByTimeDilation: Bool = false;

delaySystem.DelayCallback(CustomCallback.Create(inputInt), delay, isAffectedByTimeDilation);
```

{% hint style="info" %}
You can take a look at [Generic callbacks](https://wiki.redmodding.org/redscript/references-and-examples/common-patterns/generic-callbacks) for more use cases.
{% endhint %}