Type Method

predicateForObjectsWithMetadataKey:

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

Declaration

+ (NSPredicate *)predicateForObjectsWithMetadataKey:(NSString *)key;

Parameters

key

The metadata key to match. For a list of preset keys, see Metadata Keys. You may also search for custom keys.

Return Value

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

Discussion

Use this convenience method to create a predicate that finds all objects with a specific key stored in their metadata. The following sample uses both the convenience method and a predicate format string to create equivalent predicates.

NSPredicate *metadataKey =
    [HKQuery predicateForObjectsWithMetadataKey:HKMetadataKeyFoodType];
 
NSPredicate *explicitMetadataKey =
    [NSPredicate predicateWithFormat:@"%K.%K != nil",
     HKPredicateKeyPathMetadata,
     HKMetadataKeyFoodType];

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.

+ predicateForObjectsFromDevices:

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

+ 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: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.