A request to create, delete, or modify a Photos asset collection, for use in a photo library change block.
- iOS 8.0+
- tvOS 10.0+
You use the
PHAssetCollectionChangeRequest class to request changes for
PHAssetCollection objects. To make changes to asset collections (such as user-created albums) in the Photos library, create a change request using the appropriate class method for the change you want to perform.
creationRequestForAssetCollection(withTitle:)method to create a new asset collection.
deleteAssetCollections(_:)method to delete existing asset collections.
Before creating a change request, use the
canPerform(_:) method to verify that the collection allows the edit operation you’re requesting. If you attempt to perform an unsupported edit operation, Photos throws an exception.
A change request for creating or modifying an asset collection works like a mutable version of the asset collection object. Use the change request’s properties and instance methods to request changes to the asset collection itself. For example, the following code removes an asset from an album:
After Photos runs the change block and calls your completion handler, the asset collection’s state reflects the changes you requested in the block.
If you create or use a change request object outside a photo library change block, Photos raises an Objective-C exception. For details on change blocks, see