realm/realm-swift v10.29.0 on GitHub

Enhancements

Add support for asymmetric sync. When a class inherits from AsymmetricObject, objects created are synced unidirectionally to the server and cannot be queried or read locally.

    class PersonObject: AsymmetricObject {
       @Persisted(primaryKey: true) var _id: ObjectId
       @Persisted var name: String
       @Persisted var age: Int
    }

    try realm.write {
       // This will create the object on the server but not locally.
       realm.create(PersonObject.self, value: ["_id": ObjectId.generate(),
                                               "name": "Dylan",
                                               "age": 20])
    }

Add ability to section a collection which conforms to RealmCollection, RLMCollection. Collections can be sectioned by a unique key retrieved from a keyPath or a callback and will return an instance of SectionedResults/RLMSectionedResults. Each section in the collection will be an instance of ResultsSection/RLMSection which gives access to the elements corresponding to the section key. SectionedResults/RLMSectionedResults and ResultsSection/RLMSection have the ability to be observed.
```
class DemoObject: Object {
    @Persisted var title: String
    @Persisted var date: Date
    var firstLetter: String {
        return title.first.map(String.init(_:)) ?? ""
    }
}
var sectionedResults: SectionedResults<String, DemoObject>
// ...
sectionedResults = realm.objects(DemoObject.self)
    .sectioned(by: \.firstLetter, ascending: true)
```

Add @ObservedSectionedResults for SwiftUI support. This property wrapper type retrieves sectioned results from a Realm using a keyPath or callback to determine the section key.

struct DemoView: View {
    @ObservedSectionedResults(DemoObject.self,
                              sectionKeyPath: \.firstLetter) var demoObjects

    var body: some View {
        VStack {
            List {
                ForEach(demoObjects) { section in
                    Section(header: Text(section.key)) {
                        ForEach(section) { object in
                            MyRowView(object: object)
                        }
                    }
                }
            }
        }
    }
}

Add automatic handing for changing top-level objects to embedded objects in migrations. Any objects of the now-embedded type which have zero incoming links are deleted, and objects with multiple incoming links are duplicated. This happens after the migration callback function completes, so there is no functional change if you already have migration logic which correctly handles this. (Core #5737).
Improve performance when a new Realm file connects to the server for the first time, especially when significant amounts of data has been written while offline. (Core #5772)
Shift more of the work done on the sync worker thread out of the write transaction used to apply server changes, reducing how long it blocks other threads from writing. (Core #5772)
Improve the performance of the sync changeset parser, which speeds up applying changesets from the server. (Core #5772)

Fixed

Fix all of the UBSan failures hit by our tests. It is unclear if any of these manifested as visible bugs. (Core #5665)
Upload completion callbacks were sometimes called before the final step of interally marking the upload as complete, which could result in calling Realm.writeCopy() from the completion callback failing due to there being unuploaded changes. (Core #4865).
Writing to a Realm stored on an exFAT drive threw the exception "fcntl() with F_BARRIERFSYNC failed: Inappropriate ioctl for device" when a write transaction needed to expand the file. (Core #5789, since 10.27.0)
Syncing a Decimal128 with big significand could result in a crash. (Core #5728)

Compatibility

Realm Studio: 11.0.0 or later.
APIs are backwards compatible with all previous releases in the 10.x.y series.
Carthage release for Swift is built with Xcode 13.4.1.
CocoaPods: 1.10 or later.
Xcode: 13.1-14 RC.

Internal

Upgraded realm-core from 12.5.1 to 12.6.0