是否可以在 RealmSwift 中使用枚举？

Question

我想做这样的事情：

enum WeekDay {
    case Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}

class Person: Object {

    dynamic var birthday: WeekDay? = .Monday
    dynamic var id: String? = nil
    dynamic var birthdayRaw: String? = nil

    override static func primaryKey() -> String? {
        return "id"
    }
}

但是，我收到错误：

属性不能被标记为动态，因为它的类型不能是 以 Objective-C 表示

我该如何解决这个问题？感谢您的帮助。

Answer 1

Realm 没有直接的方法来做到这一点。 Github 问题。

但是你可以考虑这个技巧

enum WeekDay: String {
    case Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}

class Person: Object {
    private var _day: WeekDay?
    var birthday: WeekDay? {
        get {
            if let resolTypeRaw = birthdayRaw  {
                _day = WeekDay(rawValue: resolTypeRaw)
                return _day
            }
            return .Sunday
        }
        set {
            birthdayRaw = newValue?.rawValue
            _day = newValue
        }
    }

    dynamic var id: String? = nil
    dynamic var birthdayRaw: String? = nil

    override static func primaryKey() -> String? {
        return "id"
    }
}

Answer 2

从 Realm 3.x 开始，您可以使用基于 Int 的枚举（显然，有副作用）。

从 Realm 4.1 开始，您可以通过遵守“RealmEnum”协议来使用任何 RawRepresentable 枚举（Int、Float、String）。 拉取请求中的详细信息

Answer 3

我创建了一个扩展，希望对您有帮助

import RealmSwift

protocol RealmPersistableEnum: RawRepresentable, _OptionalPersistable { }

extension RealmPersistableEnum where RawValue: _OptionalPersistable {
    static func _rlmGetProperty(_ obj: ObjectBase, _ key: PropertyKey) -> Self {
        Self(rawValue: RawValue._rlmGetProperty(obj, key)) ?? Self()
    }

    static func _rlmGetPropertyOptional(_ obj: ObjectBase, _ key: PropertyKey) -> Self? {
        guard let value = RawValue._rlmGetPropertyOptional(obj, key) else { return nil }
        return Self(rawValue: value)
    }
    
    static func _rlmSetProperty(_ obj: ObjectBase, _ key: PropertyKey, _ value: Self) {
        RawValue._rlmSetProperty(obj, key, value.rawValue)
    }
}

使用示例

enum SomeEnumInt: Int, RealmPersistableEnum {
    case none = 0
    case test = 1
    case debug = 2

    init() {
        self = .none
    }
}

enum SomeEnumString: String, RealmPersistableEnum {
    case none
    case test
    case debug

    init() {
        self = .none
    }
}

class Foo: Object {
    @Persisted var v1: String
    @Persisted var v2: SomeEnumInt
    @Persisted var v3: SomeEnumString
}

Answer 4

enum QuestIcon: String, RawRepresentable, CaseIterable {
    case tray = "tray.2.fill"
    case charBook = "character.book.closed.fill"
}

extension QuestIcon: PersistableEnum  { } // THIS!!!!!!!