Convert JSON date strings to date objects automatically using reflection

RealmObjectExtensions.swift

extension Object {
    static func setPropertiesToDate(in dict: [String: Any]) -> [String: Any] {
        var dict = dict
        for property in dateConvertibles {
            if let dateStr = dict[property] as? String,
                let date = dateStr.toISODate()?.date {
                dict[property] = date
            } else if (dict[property] as? Date) != nil {
                continue
            } else {
                dict[property] = nil
            }
        }
        return dict
    }

    private func getDateConvertibles() -> [String] {
        var dates = [String]()
        for case let (label?, value) in Mirror(reflecting: self as Any).children {
            if value is Date {
                dates.append(label)
            } else {
                let submirror = Mirror(reflecting: value)
                if submirror.subjectType == (Optional<Date>).self {
                    dates.append(label)
                }
            }
        }
        return dates
    }

    private static var dateConvertibles: [String] {
        let key = self.className()
        if let dateConvertibles = dateConvertibleStore[key] {
            return dateConvertibles
        } else {
            let convertibles = self.init().getDateConvertibles()
            dateConvertibleStore[key] = convertibles
            return convertibles
        }
    }

    private static var dateConvertibleStore: [String: [String]] = {
        return [String: [String]]()
    }()

    static func stringifyDates(in dict: inout [String: Any]) {
        for key in dict.keys {
            if let date = dict[key] as? Date {
                dict[key] = date.iso8601
            }
        }
    }
}