# outlineView(_:dataCellFor:item:) Returns the cell to use in a given column for a given item. ``` @MainActor optional func outlineView(_ outlineView: NSOutlineView, dataCellFor tableColumn: NSTableColumn?, item: Any) -> NSCell? ``` ## Parameters `outlineView` The outline view that sent the message. `tableColumn` The table column that requires the cell. This value can be `nil`. `item` The item that requires the cell. ## Return Value The cell to use in column `tableColumn` for item `item`, or `nil`. Because the outline view might copy the cell, the cell must properly implement . ## Discussion You can return a different data cell for any table column and item combination. Alternatively, you can return a full-width cell for the entire row. If `tableColumn` is non-`nil`, you can return a cell. In most cases, however, you default to returning the result from [`tableView(_:dataCellFor:row:)`](/documentation/AppKit/NSTableViewDelegate/tableView(_:dataCellFor:row:)). At the time of drawing, the outline view calls each row identified by `item` with a `nil` value for `tableColumn`. At this point, you can return a cell that the system can use to draw the entire row, acting as a group. If you return a cell for the `nil` table column, prepare the other corresponding data source implementations and delegate methods to accept a `nil` value for `tableColumn`. If you don’t return a cell for the `nil` table column, the outline view calls this method once for each column, as usual. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)