---
title: "begin(completionHandler:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nssavepanel/begin(completionhandler:)"
---

# begin(completionHandler:)

Presents the panel as a modeless window.

## Declaration

```swift
func begin(completionHandler handler: @escaping (NSApplication.ModalResponse) -> Void)
```

```swift
func begin() async -> NSApplication.ModalResponse
```

## Parameters

- `handler`: The block to call after the user closes the panel. This block has no return value and takes a single parameter:

## Discussion

Discussion Configure all of the relevant properties of the panel before you call this method.

## See Also

### Showing the Panel

- [beginSheetModal(for:completionHandler:)](appkit/nssavepanel/beginsheetmodal(for:completionhandler:).md)
- [runModal()](appkit/nssavepanel/runmodal().md)
- [validateVisibleColumns()](appkit/nssavepanel/validatevisiblecolumns().md)