---
title: willExpandItemHandler
framework: uikit
role: symbol
role_heading: Instance Property
path: uikit/uicollectionviewdiffabledatasourcesectionsnapshothandlers/willexpanditemhandler
---

# willExpandItemHandler

The handler that prepares the diffable data source for expanding an item.

## Declaration

```occ
@property (nonatomic, copy, nullable) void (^willExpandItemHandler)(ItemType );
```

## See Also

### Expanding and collapsing items

- [shouldCollapseItemHandler](uikit/uicollectionviewdiffabledatasourcesectionsnapshothandlers/shouldcollapseitemhandler.md)
- [shouldExpandItemHandler](uikit/uicollectionviewdiffabledatasourcesectionsnapshothandlers/shouldexpanditemhandler.md)
- [willCollapseItemHandler](uikit/uicollectionviewdiffabledatasourcesectionsnapshothandlers/willcollapseitemhandler.md)
- [snapshotForExpandingParentItemHandler](uikit/uicollectionviewdiffabledatasourcesectionsnapshothandlers/snapshotforexpandingparentitemhandler.md)