swift - 可编码为 CKRecord

Question

我有几个可编码的结构，我想创建一个通用协议(protocol)来将它们编码为 CloudKit 的 CKRecord 并解码回来。

我有一个用于创建字典的 Encodable 扩展:

extension Encodable {

    var dictionary: [String: Any] {
        return (try? JSONSerialization.jsonObject(with: JSONEncoder().encode(self), options: .allowFragments)) as? [String: Any] ?? [:]
    }
}

然后在协议(protocol)扩展中，我将记录创建为属性，如果类型是数据，我会尝试创建一个 CKAsset。

var ckEncoded: CKRecord? {

    // Convert self.id to CKRecord.name (CKRecordID)
    guard let idString = self.id?.uuidString else { return nil }
    let record = CKRecord(recordType: Self.entityType.rawValue,
                          recordID: CKRecordID(recordName: idString))

    self.dictionary.forEach {

        if let data = $0.value as? Data {
            if let asset: CKAsset = try? ckAsset(from: data, id: idString) { record[$0.key] = asset }
        } else {
            record[$0.key] = $0.value as? CKRecordValue
        }
    }

    return record
}

解码:

func decode(_ ckRecord: CKRecord) throws {

    let keyIntersection = Set(self.dtoEncoded.dictionary.keys).intersection(ckRecord.allKeys())
    var dictionary: [String: Any?] = [:]

    keyIntersection.forEach {

        if let asset = ckRecord[$0] as? CKAsset {
            dictionary[$0] = try? self.data(from: asset)
        } else {
            dictionary[$0] = ckRecord[$0]
        }
    }

    guard let data = try? JSONSerialization.data(withJSONObject: dictionary) else { throw Errors.LocalData.isCorrupted }
    guard let dto = try? JSONDecoder().decode(self.DTO, from: data) else { throw  Errors.LocalData.isCorrupted }


    do { try decode(dto) }
    catch { throw error }
} 

除数据类型外，一切都来回运作。字典里查不出来。所以，我无法将其转换为 CKAsset。提前谢谢你。

Answer 1

我还发现到目前为止，Apple 还没有对此提供明确的支持。

我的解决方案是手动编码/解码:在我的 Codable 子类上我添加了两个方法:

/// Returns CKRecord
func ckRecord() -> CKRecord {
    let record = CKRecord(recordType: "MyClassType")
    record["title"] = title as CKRecordValue
    record["color"] = color as CKRecordValue
    return record
}


init(withRecord record: CKRecord) {
    title = record["title"] as? String ?? ""
    color = record["color"] as? String ?? kDefaultColor
}

另一种针对更复杂情况的解决方案是使用一些第 3 方库，我遇到的一个是:https://github.com/insidegui/CloudKitCodable