Bundle a Realm File - Swift SDK

try await createBundledRealm()
// Opening a realm and accessing it must be done from the same thread.
// Marking this function as `@MainActor` avoids threading-related issues.
@MainActor
func createBundledRealm() async throws {
    let app = App(id: YOUR_APP_SERVICES_APP_ID)
    // Log in the user whose realm you want to copy for bundling
    let seedUser = try await app.login(credentials: Credentials.anonymous)
    // Create a configuration to open the seed user's realm
    var config = seedUser.configuration(partitionValue: "Partition You Want to Bundle")
    config.objectTypes = [Todo.self]
    
    // Open the realm with the seed user's config
    let realm = try await Realm(configuration: config, downloadBeforeOpen: .always)
    print("Successfully opened realm: \(realm)")
    
    // Verify there is a todo object in the realm whose
    // owner's name is "Daenerys". When we open the bundled
    // realm later, we should see the same result.
    let todos = realm.objects(Todo.self)
    let daenerysTodos = todos.where { $0.owner == "Daenerys" }
    XCTAssertEqual(daenerysTodos.count, 1)
    // Specify an output directory for the bundled realm
    // We're using FileManager here for tested code examples,
    // but this could be a static directory on your computer.
    guard let outputDir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
    // Append a file name to complete the path
    let bundleRealmFilePath = outputDir.appendingPathComponent("seed.realm")
    // Update the config file path to the path where you want to save the bundled realm
    config.fileURL = bundleRealmFilePath
    // Check to see if there is already a realm at the bundled realm file path. If there
    // is already a realm there, delete it.
    if Realm.fileExists(for: config) {
        try Realm.deleteFiles(for: config)
        print("Successfully deleted existing realm at path: \(bundleRealmFilePath)")
    } else {
        print("No file currently exists at path")
    }
    // Write a copy of the realm at the URL we specified
    try realm.writeCopy(configuration: config)
    // Verify that we successfully made a copy of the realm
    XCTAssert(FileManager.default.fileExists(atPath: bundleRealmFilePath.path))
    print("Successfully made a copy of the realm at path: \(bundleRealmFilePath)")
    
    // Verify that opening the realm at the new file URL works.
    // Don't download changes, because this can mask a copy
    // that does not contain the expected data.
    let copiedRealm = try await Realm(configuration: config, downloadBeforeOpen: .never)
    print("Successfully opened realm: \(realm)")
    // Verify that the copied realm contains the data we expect
    let copiedTodos = copiedRealm.objects(Todo.self)
    let daenerysCopiedTodos = copiedTodos.where { $0.owner == "Daenerys" }
    XCTAssertEqual(daenerysCopiedTodos.count, 1)
    print("Copied realm opens and contains this many tasks: \(daenerysCopiedTodos.count)")
}

try await openBundledSyncedRealm()
// Opening a realm and accessing it must be done from the same thread.
// Marking this function as `@MainActor` avoids threading-related issues.
@MainActor
func openBundledSyncedRealm() async throws {
    let app = App(id: YOUR_APP_SERVICES_APP_ID)
    // Log in an app user who will use the bundled realm
    let user = try await app.login(credentials: Credentials.anonymous)
    // Create a configuration for the app user's realm
    // This should use the same partition value as the bundled realm
    var newUserConfig = user.configuration(partitionValue: "Partition You Want to Bundle")
    newUserConfig.objectTypes = [Todo.self]
    // Find the path of the seed.realm file in your project
    let realmURL = Bundle.main.url(forResource: "seed", withExtension: ".realm")
    print("The bundled realm URL is: \(realmURL)")
    // When you use the `seedFilePath` parameter, this copies the
    // realm at the specified path for use with the user's config
    newUserConfig.seedFilePath = realmURL
    // Open the synced realm, downloading any changes before opening it.
    // This starts with the existing data in the bundled realm, but checks
    // for any updates to the data before opening it in your application.
    let realm = try await Realm(configuration: newUserConfig, downloadBeforeOpen: .always)
    print("Successfully opened the bundled realm")
    // Read and write to the bundled realm as normal
    let todos = realm.objects(Todo.self)
    // There should be one todo whose owner is Daenerys because that's
    // what was in the bundled realm.
    var daenerysTodos = todos.where { $0.owner == "Daenerys" }
    XCTAssertEqual(daenerysTodos.count, 1)
    print("The bundled realm has \(daenerysTodos.count) todos whose owner is Daenerys")
    // Write as usual to the realm, and see the object count increment
    let todo = Todo(value: ["name": "Banish Ser Jorah", "owner": "Daenerys", "status": "In Progress"])
    try realm.write {
        realm.add(todo)
    }
    print("Successfully added a todo to the realm")
    daenerysTodos = todos.where { $0.owner == "Daenerys" }
    XCTAssertEqual(daenerysTodos.count, 2)
}