DataStoreManagerDelegate

Tells the delegate that the specified storage type of a data store needs to perform migration.

Handle the logic to perform the migration. For example:

switch version {
case 0:
    migrateFromVersionZeroToOne()
    fallthrough
case 1:
    migrateFromVersionOneToTwo()
default:
    break
}

After the delegate method is called, the schema version will be updated to the version defined in dataStoreManager(_:currentSchemaVersionForType:)

Asks the delegate for the cost with which associate to the object.

When memory is limited or when the total cost of the cache eclipses the maximum allowed total cost, the cache could begin an eviction process to remove some of its elements. However, this eviction process is not in a guaranteed order. As a consequence, if you try to manipulate the cost values to achieve some specific behavior, the consequences could be detrimental to your program. Typically, the obvious cost is the size of the value in bytes. If that information is not readily available, you should not go through the trouble of trying to compute it, as doing so will drive up the cost of using the cache. Pass in 0 for the cost value if you otherwise have nothing useful to pass.

Unlike an NSMutableDictionary object, a cache does not copy the key objects that are put into it.

Asks the delegate for the cloud kit container record type of the data store manager.

Use this string to differentiate between different record types in your app. The string is primarily for your benefit, so choose type names that reflect the data in the corresponding records.

Tells the delegate that the specified storage type of a data store needs to handle when the value of one or more keys in the local key-value store changed due to incoming data pushed from iCloud.

The user info dictionary can contain the reason for the notification as well as a list of which values changed, as follows:

• The value of the NSUbiquitousKeyValueStoreChangeReasonKey key, when present, indicates why the key-value store changed. Its value is one of the constants in Change Reason Values.

• The value of the [NSUbiquitousKeyValueStoreChangedKeysKey(apple-reference-documentation://hsxKbLUIAR), when present, is an array of strings, each the name of a key whose value changed.