---
title: "callAsFunction(id:value:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/openwindowaction/callasfunction(id:value:)"
---

# callAsFunction(id:value:)

Opens a window defined by the window group that presents the specified value type and that’s associated with the specified identifier.

## Declaration

```swift
@MainActor @preconcurrency func callAsFunction<D>(id: String, value: D) where D : Decodable, D : Encodable, D : Hashable
```

## Parameters

- `id`: The identifier of the scene to present.
- `value`: The value to present.

## Discussion

Discussion Don’t call this method directly. SwiftUI calls it when you call the openWindow action with an identifier and a value: openWindow(id: "message", value: message.id) For information about how Swift uses the callAsFunction() method to simplify call site syntax, see Methods with Special Names in The Swift Programming Language.

## See Also

### Calling the action

- [callAsFunction(id:)](swiftui/openwindowaction/callasfunction(id:).md)
- [callAsFunction(value:)](swiftui/openwindowaction/callasfunction(value:).md)