Structures

This struct enables sequence-style enumeration for RLMObjects in Swift via RLMCollection.makeIterator

This struct enables sequence-style enumeration for RLMDictionary in Swift via RLMDictionary.makeIterator

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.

Container type which holds the offset of the element in the Map.

Container for holding a single key-value entry in a Map. This is used where a tuple cannot be expressed as a generic argument.

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.

@Persisted is used to declare properties on Object subclasses which should be managed by Realm.

Example of usage:

class MyModel: Object {
    // A basic property declaration. A property with no
    // default value supplied will default to `nil` for
    // Optional types, zero for numeric types, false for Bool,
    // an empty string/data, and a new random value for UUID
    // and ObjectID.
    @Persisted var basicIntProperty: Int

    // Custom default values can be specified with the
    // standard Swift syntax
    @Persisted var intWithCustomDefault: Int = 5

    // Properties can be indexed by passing `indexed: true`
    // to the initializer.
    @Persisted(indexed: true) var indexedString: String

    // Properties can set as the class's primary key by
    // passing `primaryKey: true` to the initializer
    @Persisted(primaryKey: true) var _id: ObjectId

    // List and set properties should always be declared
    // with `: List` rather than `= List()`
    @Persisted var listProperty: List<Int>
    @Persisted var setProperty: MutableSet<MyObject>

    // LinkingObjects properties require setting the source
    // object link property name in the initializer
    @Persisted(originProperty: "outgoingLink")
    var incomingLinks: LinkingObjects<OtherModel>

    // Properties which are not marked with @Persisted will
    // be ignored entirely by Realm.
    var ignoredProperty = true
}

Int, Bool, String, ObjectId and Date properties can be indexed by passing indexed: true to the initializer. Indexing a property improves the performance of equality queries on that property, at the cost of slightly worse write performance. No other operations currently use the index.

A property can be set as the class’s primary key by passing primaryKey: true to the initializer. Compound primary keys are not supported, and setting more than one property as the primary key will throw an exception at runtime. Only Int, String, UUID and ObjectID properties can be made the primary key, and when using MongoDB Realm, the primary key must be named _id. The primary key property can only be mutated on unmanaged objects, and mutating it on an object which has been added to a Realm will throw an exception.

Properties can optionally be given a default value using the standard Swift syntax. If no default value is given, a value will be generated on first access: nil for all Optional types, zero for numeric types, false for Bool, an empty string/data, and a new random value for UUID and ObjectID. List and MutableSet properties should not be defined by setting them to a default value of an empty List/MutableSet. Doing so will work, but will result in worse performance when accessing objects managed by a Realm. Similarly, ObjectID properties should not be initialized to ObjectID.generate(), as doing so will result in extra ObjectIDs being generated and then discarded when reading from a Realm.

If a class has at least one @Persisted property, all other properties will be ignored by Realm. This means that they will not be persisted and will not be usable in queries and other operations such as sorting and aggregates which require a managed property.

@Persisted cannot be used anywhere other than as a property on an Object or EmbeddedObject subclass and trying to use it in other places will result in runtime errors.

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.

An iterator for a RealmKeyedCollection instance.

An iterator for Map<Key, Value> which produces (key: Key, value: Value) pairs for each entry in the map.

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 property wrapper type that instantiates an observable object.

Create a state realm object in a SwiftUI/View, SwiftUI/App, or SwiftUI/Scene by applying the @StateRealmObject attribute to a property declaration and providing an initial value that conforms to the doc://com.apple.documentation/documentation/Combine/ObservableObject protocol:

@StateRealmObject var model = DataModel()

SwiftUI creates a new instance of the object only once for each instance of the structure that declares the object. When published properties of the observable realm object change, SwiftUI updates the parts of any view that depend on those properties. If unmanaged, the property will be read from the object itself, otherwise, it will be read from the underlying Realm. Changes to the value will update the view asynchronously:

Text(model.title) // Updates the view any time `title` changes.

You can pass the state object into a property that has the SwiftUI/ObservedRealmObject attribute.

Get a SwiftUI/Binding to one of the state object’s properties using the $ operator. Use a binding when you want to create a two-way connection to one of the object’s properties. For example, you can let a SwiftUI/Toggle control a Boolean value called isEnabled stored in the model:

Toggle("Enabled", isOn: $model.isEnabled)

This will write the modified isEnabled property to the model object’s Realm.

A property wrapper type that retrieves results from a Realm.

The results use the realm configuration provided by the environment value EnvironmentValues/realmConfiguration.

A property wrapper type that subscribes to an observable Realm Object or List and invalidates a view whenever the observable object changes.

A property wrapper type that initiates a Realm.asyncOpen() for the current user which asynchronously open a Realm, and notifies states for the given process

Add AsyncOpen to your SwiftUI/View or SwiftUI/App, after a user is already logged in, or if a user is going to be logged in

@AsyncOpen(appId: "app_id", partitionValue: <partition_value>) var asyncOpen

This will immediately initiates a Realm.asyncOpen() operation which will perform all work needed to get the Realm to a usable state. (see Realm.asyncOpen() documentation)

This property wrapper will publish states of the current Realm.asyncOpen() process like progress, errors and an opened realm, which can be used to update the view

struct AsyncOpenView: View {
    @AsyncOpen(appId: "app_id", partitionValue: <partition_value>) var asyncOpen

    var body: some View {
       switch asyncOpen {
       case .notOpen:
           ProgressView()
       case .open(let realm):
           ListView()
              .environment(\.realm, realm)
       case .error(_):
           ErrorView()
       case .progress(let progress):
           ProgressView(progress)
       }
    }
}

This opened realm can be later injected to the view as an environment value which will be used by our property wrappers to populate the view with data from the opened realm

ListView()
   .environment(\.realm, realm)

AutoOpen will try once to asynchronously open a Realm, but in case of no internet connection will return an opened realm for the given appId and partitionValue which can be used within our view. Add AutoOpen to your SwiftUI/View or SwiftUI/App, after a user is already logged in or if a user is going to be logged in

@AutoOpen(appId: "app_id", partitionValue: <partition_value>, timeout: 4000) var autoOpen

This will immediately initiates a Realm.asyncOpen() operation which will perform all work needed to get the Realm to a usable state. (see Realm.asyncOpen() documentation)

This property wrapper will publish states of the current Realm.asyncOpen() process like progress, errors and an opened realm, which can be used to update the view

struct AutoOpenView: View {
    @AutoOpen(appId: "app_id", partitionValue: <partition_value>) var autoOpen

    var body: some View {
       switch autoOpen {
       case .notOpen:
           ProgressView()
       case .open(let realm):
           ListView()
              .environment(\.realm, realm)
       case .error(_):
           ErrorView()
       case .progress(let progress):
           ProgressView(progress)
       }
    }
}

This opened realm can be later injected to the view as an environment value which will be used by our property wrappers to populate the view with data from the opened realm

ListView()
   .environment(\.realm, realm)

This property wrapper behaves similar as AsyncOpen, and in terms of declaration and use is completely identical, but with the difference of a offline-first approach.

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(_:).