Structures

A Realm instance (also referred to as “a Realm”) represents a Realm database.

Realms can either be stored on disk (see init(path:)) or in memory (see Configuration).

Realm instances are cached internally, and constructing equivalent Realm objects (for example, by using the same path or identifier) produces limited overhead.

If you specifically want to ensure a Realm instance is destroyed (for example, if you wish to open a Realm, check some property, and then possibly delete the Realm file and re-open it), place the code which uses the Realm within an autoreleasepool {} and ensure you have no other strong references to it.

LinkingObjects is an auto-updating container type. It represents zero or more objects that are linked to its owning model object through a property relationship.

LinkingObjects can be queried with the same predicates as List<Element> and Results<Element>.

LinkingObjects always reflects the current state of the Realm on the current thread, including during write transactions on the current thread. The one exception to this is when using for...in enumeration, which will always enumerate over the linking objects that were present when the enumeration is begun, even if some of them are deleted or modified to no longer link to the target object during the enumeration.

LinkingObjects can only be used as a property on Object models. Properties of this type must be declared as let and cannot be dynamic.

Results is an auto-updating container type in Realm returned from object queries.

Results can be queried with the same predicates as List<Element>, and you can chain queries to further filter query results.

Results always reflect the current state of the Realm on the current thread, including during write transactions on the current thread. The one exception to this is when using for...in enumeration, which will always enumerate over the objects which matched the query when the enumeration is begun, even if some of them are deleted or modified to be excluded by the filter during the enumeration.

Results are lazily evaluated the first time they are accessed; they only run queries when the result of the query is requested. This means that chaining several temporary Results to sort and filter your data does not perform any unnecessary work processing the intermediate state.

Once the results have been evaluated or a notification block has been added, the results are eagerly kept up-to-date, with the work done to keep them up-to-date done on a background thread whenever possible.

Results instances cannot be directly instantiated.

A type-erased RealmCollection.

Instances of RealmCollection forward operations to an opaque underlying collection having the same Element type.

A subscription which wraps a Realm notification.

A subscription which wraps a Realm AsyncOpenTask.

Migration instances encapsulate information intended to facilitate a schema migration.

A Migration instance is passed into a user-defined MigrationBlock block when updating the version of a Realm. This instance provides access to the old and new database schemas, the objects in the Realm, and provides functionality for modifying the Realm during the migration.

Information about a specific property which changed in an Object change notification.

This class represents Realm model object schemas.

When using Realm, ObjectSchema instances allow performing migrations and introspecting the database’s schema.

Object schemas map to tables in the core database.

Property instances represent properties managed by a Realm in the context of an object schema. Such properties may be persisted to a Realm file or computed from other data in the Realm.

When using Realm, property instances allow performing migrations and introspecting the database’s schema.

Property instances map to columns in the core database.

An iterator for a RealmCollection instance.

Schema instances represent collections of model object schemas managed by a Realm.

When using Realm, Schema instances allow performing migrations and introspecting the database’s schema.

Schemas map to collections of tables in the core database.

A SortDescriptor stores a key path and a sort order for use with sorted(sortDescriptors:). It is similar to NSSortDescriptor, but supports only the subset of functionality which can be efficiently run by Realm’s query engine.

A SyncConfiguration represents configuration parameters for Realms intended to sync with MongoDB Realm.

Structure providing an interface to call a MongoDB Realm function with the provided name and arguments.

user.functions.sum([1, 2, 3, 4, 5]) { sum, error in
    guard case let .int64(value) = sum else {
        print(error?.localizedDescription)
    }

    assert(value == 15)
}

The dynamic member name (sum in the above example) is directly associated with the function name. The first argument is the BSONArray of arguments to be provided to the function. The second and final argument is the completion handler to call when the function call is complete. This handler is executed on a non-main global DispatchQueue.

An object intended to be passed between threads containing a thread-safe reference to its thread-confined object.

To resolve a thread-safe reference on a target Realm on a different thread, pass to Realm.resolve(_:).