---
title: "init(id:for:content:defaultValue:)"
framework: swiftui
role: symbol
role_heading: Initializer
path: "swiftui/windowgroup/init(id:for:content:defaultvalue:)"
---

# init(id:for:content:defaultValue:)

Creates a data-presenting window group with an identifier and a default value.

## Declaration

```swift
nonisolated init<D, C>(id: String, for type: D.Type = D.self, @ContentBuilder content: @escaping (Binding<D>) -> C, defaultValue: @escaping () -> D) where Content == PresentedWindowContent<D, C>, D : Decodable, D : Encodable, D : Hashable, C : View
```

## Parameters

- `id`: A string that uniquely identifies the window group. Identifiers must be unique among the window groups in your app.
- `type`: The type of presented data this window group accepts.
- `content`: A closure that creates the content for each instance of the group. The closure receives a binding to the value that you pass into the doc://com.apple.SwiftUI/documentation/SwiftUI/EnvironmentValues/openWindow action when you open the window. SwiftUI automatically persists and restores the value of this binding as part of the state restoration process.
- `defaultValue`: A closure that returns a default value to present. SwiftUI calls this closure when it has no data to provide, like when someone opens a new window from the File > New Window menu item.

## Discussion

Discussion The window group uses the given view as a template to form the content of each window in the group. SwiftUI creates a window from the group when you present a value of the specified type using the openWindow action.

## See Also

### Identifying a window group that has default data

- [init(_:id:for:content:defaultValue:)](swiftui/windowgroup/init(_:id:for:content:defaultvalue:).md)