---
title: "collapseItem(_:collapseChildren:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nsoutlineview/collapseitem(_:collapsechildren:)"
---

# collapseItem(_:collapseChildren:)

Collapses a given item and, optionally, its children.

## Declaration

```swift
func collapseItem(_ item: Any?, collapseChildren: Bool)
```

## Parameters

- `item`: An item in the receiver. Starting in OS X version 10.5, passing 'nil' will collapse each item under the root in the outline view.
- `collapseChildren`: If doc://com.apple.documentation/documentation/Swift/true, recursively collapses item and its children. If doc://com.apple.documentation/documentation/Swift/false, collapses item only (identical to doc://com.apple.appkit/documentation/AppKit/NSOutlineView/collapseItem(_:)).

## Discussion

Discussion For example, this method is invoked with the collapseChildren parameter set to true when a user Option-clicks the disclosure triangle for an item in the outline view (to collapse the item and all its contained items). For each item collapsed, posts an item collapsed notification.

## See Also

### Expanding and Collapsing the Outline

- [expandItem(_:)](appkit/nsoutlineview/expanditem(_:).md)
- [expandItem(_:expandChildren:)](appkit/nsoutlineview/expanditem(_:expandchildren:).md)
- [collapseItem(_:)](appkit/nsoutlineview/collapseitem(_:).md)