Type Method

predicateForObjectsFromDevices:

Returns a predicate that matches all the objects that were created by any of the provided devices.

Declaration

+ (NSPredicate *)predicateForObjectsFromDevices:(NSSet<HKDevice *> *)devices;

Parameters

devices

A set of devices that have generated the data for objects stored in the HealthKit store.

Return Value

A predicate that matches all the objects that store data generated by any of the provided devices.

Discussion

When creating the device objects for this predicate, only pass in values for the parameters you need for your query. HealthKit returns all the devices that match the non-nil parameters. This gives you a great deal of control when it comes to fine tuning your query. For example, setting the localIdentifier and the firmwareVersion parameters lets you query for all the samples generated by a specific device running a specific version of the firmware. Just setting the manufacturer and model casts a much broader net.

The following sample uses both the convenience method and a predicate format string to create equivalent predicates.

NSPredicate *fromDevices = [HKQuery predicateForObjectsFromDevices:devices];
 
NSPredicate *explicitFromDevices = [NSPredicate predicateWithFormat:@"%K IN %@",
                                    HKPredicateKeyPathDevice,
                                    devices];

See Also

Creating Object Predicates

+ predicateForObjectWithUUID:

Returns a predicate that matches an object with the specified universally unique identifier (UUID).

+ predicateForObjectsWithUUIDs:

Returns a predicate that matches the objects with the specified universally unique identifiers (UUIDs).

+ predicateForObjectsFromSource:

Returns a predicate that matches all the objects that were created by the provided source.

+ predicateForObjectsFromSources:

Returns a predicate that matches all the objects that were created by any of the provided sources.

+ predicateForObjectsWithDeviceProperty:allowedValues:

Returns a predicate that matches all objects created by devices with the specified properties.

+ predicateForObjectsFromSourceRevisions:

Returns a predicate that matches all the objects that were created by any of the provided source revisions.

+ predicateForObjectsWithMetadataKey:

Returns a predicate that matches any object whose metadata contains the provided key.

+ predicateForObjectsWithMetadataKey:allowedValues:

Returns a predicate that matches objects based on the provided metadata key and an array of target values.

+ predicateForObjectsWithMetadataKey:operatorType:value:

Returns a predicate that matches objects based on the provided metadata key, value, and operator.

+ predicateForObjectsWithNoCorrelation

Returns a predicate that matches all objects that are not associated with a HealthKit correlation.