---
title: "pageController(_:identifierFor:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nspagecontrollerdelegate/pagecontroller(_:identifierfor:)"
---

# pageController(_:identifierFor:)

Return the identifier of the view controller that owns a view to display the object.

## Declaration

```swift
@MainActor optional func pageController(_ pageController: NSPageController, identifierFor object: Any) -> NSPageController.ObjectIdentifier
```

## Parameters

- `pageController`: The page controller.
- `object`: The object to display.

## Return Value

Return Value Returns a string identifier for the view controller for the specified object.

## Discussion

Discussion If pageController does not have an unused view controller for this identifier, the you will be asked to create one via pageController(_:viewControllerForIdentifier:).

## See Also

### Managing View Controllers

- [pageController(_:viewControllerForIdentifier:)](appkit/nspagecontrollerdelegate/pagecontroller(_:viewcontrollerforidentifier:).md)
- [pageController(_:prepare:with:)](appkit/nspagecontrollerdelegate/pagecontroller(_:prepare:with:).md)
- [pageController(_:frameFor:)](appkit/nspagecontrollerdelegate/pagecontroller(_:framefor:).md)
- [NSPageController.ObjectIdentifier](appkit/nspagecontroller/objectidentifier.md)