The set of source types for which to include assets in the fetch result.
- iOS 9+
- macOS 10.13+
- UIKit for Mac 13.0+Beta
- tvOS 10+
Asset source types identify the means by which an asset enters the Photos library, and affect the possible actions you can perform on an asset. For example, assets synced from iTunes cannot be edited or deleted.
PHAsset type is an option set—to include multiple source types in the same query, combine type constants with the bitwise OR operator (Objective-C) or OptionSetType set syntax (Swift).