---
title: interactionActivityTrackingBaseName
framework: uikit
role: symbol
role_heading: Instance Property
path: uikit/uiviewcontroller/interactionactivitytrackingbasename
---

# interactionActivityTrackingBaseName

The base name the view controller uses for logging signposts that annotate user interactions.

## Declaration

```swift
var interactionActivityTrackingBaseName: String? { get set }
```

## Discussion

Discussion To help you investigate perfomance issues in your app, UIKit annotates significant user interactions with signpost messages. It creates activities that span the duration of the interaction and sets one of the ProcessInfo.ActivityOptions for tracking: animationTrackingEnabled or trackingEnabled. Use this property to customize the tracking name the activity uses in the signpost messages. Scroll views that can derive their enclosing view controller also use the tracking name to annotate interactive dragging and programmatic scrolling events. In many cases, you can set the tracking name once in init, viewDidLoad, or awakeFromNib. You can, however, change the tracking name in response to different configurations. In this example, the tracking name updates in response to toggling a switch. When not explicitly set, custom subclasses use their class name as the base name, while base classes may use the accessibilityIdentifier of the controller’s managed view. If the view controller is a prominent child view controller of a UINavigationController, UITabBarController, or UISplitViewController, the parent may derive a name by applying a prefix: UINC- for a navigation controller UITBC- for a tab bar controller UISVC- for a split view controller The system applies a suffix to the base name to denote the type of user interaction: -Appearing when presenting the view controller -Disappearing when dismising the view controller -Scrolling when scrolling the view controller’s managed UIScrollView -Dragging when dragging the view controller’s managed UIScrollView For example, UIKit uses the tracking name UINC-MyListTableViewController-Appearing in a signpost when presenting a navigation controler with a MyListTableViewController prominent child controller.

## See Also

### Related Documentation

- [Recording Performance Data](os/recording-performance-data.md)
- [Improving app responsiveness](xcode/improving-app-responsiveness.md)