---
title: openWindow
framework: swiftui
role: symbol
role_heading: Instance Property
path: swiftui/environmentvalues/openwindow
---

# openWindow

A window presentation action stored in a view’s environment.

## Declaration

```swift
var openWindow: OpenWindowAction { get }
```

## Discussion

Discussion Use the openWindow environment value to get an OpenWindowAction instance for a given Environment. Then call the instance to open a window. You call the instance directly because it defines a callAsFunction(id:) method that Swift calls when you call the instance. For example, you can define a button that opens a new mail viewer window: @main struct Mail: App {     var body: some Scene {         WindowGroup(id: "mail-viewer") {             MailViewer()         }     } }

struct NewViewerButton: View {     @Environment(\.openWindow) private var openWindow

var body: some View {         Button("Open new mail viewer") {             openWindow(id: "mail-viewer")         }     } } You indicate which scene to open by providing one of the following: A string identifier that you pass through the id parameter, as in the above example. A value parameter that has a type that matches the type that you specify in the scene’s initializer. Both an identifier and a value. This enables you to define multiple window groups that take input values of the same type like a UUID. Use the first option to target either a WindowGroup or a Window scene in your app that has a matching identifier. For a WindowGroup, the system creates a new window for the group. If the window group presents data, the system provides the default value or nil to the window’s root view. If the targeted scene is a Window, the system orders it to the front. Use the other two options to target a WindowGroup and provide a value to present. If the interface already has a window from the group that’s presenting the specified value, the system brings the window to the front. Otherwise, the system creates a new window and passes a binding to the specified value.

## See Also

### Opening windows

- [Presenting windows and spaces](visionos/presenting-windows-and-spaces.md)
- [supportsMultipleWindows](swiftui/environmentvalues/supportsmultiplewindows.md)
- [OpenWindowAction](swiftui/openwindowaction.md)
- [PushWindowAction](swiftui/pushwindowaction.md)