I have a photo editing application, and I'd like to provide a "projects" feature that references photos from the user's Photos library instead of having to import copies of them (thereby wasting space on users' devices) in order to provide non-destructive editability. I also want to display the projects in a particular way and have project data persist across devices and backups. I am aware of the ability to save edits to Photos via PhotoKit, but there doesn't appear to be a way to query for all assets edited with a particular application, which is why I want to maintain my own database of assets edited with my app. However, I'm having trouble finding a way to reliably identify PHAssets across devices and backup restorations.
The documentation for PHObject.localIdentifier says it's a "unique string that persistently identifies the object." However, the "local" in localIdentifier suggests that it's not consistent across instances of a photo library on separate devices or between backup restorations. However, I can't find any documentation that explicitly states this. Can anyone shed light on how these identifiers are intended to behave?
The documentation for PHObject.localIdentifier says it's a "unique string that persistently identifies the object." However, the "local" in localIdentifier suggests that it's not consistent across instances of a photo library on separate devices or between backup restorations. However, I can't find any documentation that explicitly states this. Can anyone shed light on how these identifiers are intended to behave?