A query-based subscription uses its search predicate to identify potential matches for records. It combines the predicate information with the value in the subscriptionOptions property to determine the conditions under which to send a push notification to the app.
The search predicate defines the records that the subscription object monitors for changes. The value in this property is used only if the subscriptionType property is set to CKSubscriptionTypeQuery; otherwise, it is ignored.
A query-based subscription can be used to observe multiple records or a single record. An example of subscribing to the changes of a single record is shown below:
The record type being monitored in a query-based subscription.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.