Contents

fetchRecordZoneChanges(inZoneWith:since:desiredKeys:resultsLimit:completionHandler:)

Fetches all modified records from a specific record zone and delivers them to a completion handler.

Declaration

@preconcurrency func fetchRecordZoneChanges(inZoneWith zoneID: CKRecordZone.ID, since changeToken: CKServerChangeToken?, desiredKeys: [CKRecord.FieldKey]? = nil, resultsLimit: Int? = nil, completionHandler: @escaping  @Sendable (Result<(modificationResultsByID: [CKRecord.ID : Result<CKDatabase.RecordZoneChange.Modification, any Error>], deletions: [CKDatabase.RecordZoneChange.Deletion], changeToken: CKServerChangeToken, moreComing: Bool), any Error>) -> Void)

Parameters

  • zoneID:

    The identifier of the record zone with changes.

  • changeToken:

    The change token from the previous execution of this method. If this is your app’s first fetch, or you want to refetch every change in the record zone’s history, specify nil.

  • desiredKeys:

    The fields to include on each fetched record. To include all fields, specify nil; to fetch only system fields, specify an empty array.

  • resultsLimit:

    The maximum number of changes to return. The server may use a limit lower than this value.

  • completionHandler:

    The closure to execute with the fetch results.

Discussion

The completion handler takes a single Result parameter that contains either a tuple, or an error if the request fails. For example, when the network is unavailable or the device doesn’t have an active iCloud account.

When present, the tuple contains the following named elements:

modificationResultsByID

A dictionary of record modifications that occur after the time that changeToken denotes. The dictionary uses the identifiers of modified records as its keys. The value of each key is a Result that contains either the corresponding modification, or an error that describes why CloudKit can’t provide that information.

deletions

An array of record deletions that occur after the time that changeToken denotes. Each deletion contains details about a deleted record.

changeToken

The change token that corresponds to the fetch results’ most recent change.

moreComing

A Boolean value that indicates whether the server has additional changes for you to fetch.

This method fetches record changes in the specfied record zone, such as those that occur during record creation, modification, and deletion.

Along with the fetched changes, CloudKit supplies a change token, which is an opaque token that denotes a specific point in the record zone’s history. Store this token and provide it the next time you execute this method. Change tokens conform to NSSecureCoding and are safe to cache on-disk. Don’t infer any behavior or order from a token’s contents.

For information on a more configurable way to fetch record zone changes, see CKFetchRecordZoneChangesOperation.

See Also

Fetching Changes