exportedAssetID(for:)

Declaration

func exportedAssetID(for resource: PHAssetResource) async throws -> CKAsset.ExportedAssetID

Parameters

• resource:

  The asset resource to get an exported asset ID for.

Return Value

The exported asset ID for the resource.

Discussion

The returned CKAsset.ExportedAssetID can be used to create a CKAsset that references the asset resource data without copying it. Network access is always required.

An exported asset ID exists only for a resource whose data iCloud Photos stores in CloudKit as its own CKAsset, e.g. the original media and adjustment renders in PHAssetResource/TypeGroup/coreComponents, and PHAssetResourceType/derivative resources in PHAssetResource/TypeGroup/mediaDerivatives.

Resources that have no CloudKit asset to reference, like the on-device generated PHAssetResourceType/thumbnailDerivative, will fail with missingResource.

Note that a resource’s type alone does not determine whether an ID is available — a library that stopped using iCloud Photos may still report resources of a referenceable type. Request an ID for the specific resource you intend to reference, and fall back to requesting the resource’s data when none is available.

The photo library must use iCloud Photos; a request against a library that doesn’t fails with requestNotSupportedForAsset.

This method supports task cancellation. If the calling task is cancelled, the underlying network request is cancelled and this method throws CancellationError.