使用Codable解析任何类型的json

Question

我很抱歉如果这个问题被回答了很多次，但我正在寻找我自己的特定json问题，这就是为什么我发布这篇文章，这是我的json它是一个通知的数组列表，在额外的对象中你可以看到它有contract对象，现在这个对象正在改变它可以是活动或反馈在json数组的第二个索引中如何使可编码的结构来解码这种类型的jsonHere是我的结构，我不能在可编码中做任何类型

struct Alert: Decodable { var id: Int? var isUnread: Bool? var userId: Int? var message: String? var notificationType: String? var extra: Any?

 "value": [
        {
            "id": 153,
            "is_unread": true,
            "user_id": 3,
            "message": "Contract offered from JohnWick. Click here to see the details.",
            "notification_type": "Contract",
            "extra": {
                "contract": {
                    "id": 477,
                    "likes": 0,
                    "shares": 0,
                    "account_reach": 0.0,
                    "followers": 0,
                    "impressions": 0.0,
                    "description": "Fsafasd",
                    "budget": 0.0,
                    "start_date": null,
                    "end_date": null,
                    "status": "pending",
                    "is_accepted": false,
                    "brand_id": 443,
                    "influencer_id": 3,
                    "proposal_id": 947,
                    "created_at": "2019-11-09T17:40:57.646Z",
                    "updated_at": "2019-11-09T17:40:57.646Z",
                    "contract_fee": 435345.0,
                    "base_fee": 5000.0,
                    "transaction_fee": 43534.5,
                    "total_fee": 483879.5,
                    "infuencer_completed": false,
                    "brand_completed": false,
                    "comments": 0
                }
            }
        },
{
            "id": 152,
            "is_unread": true,
            "user_id": 3,
            "message": "Message from JohnWick. Click here to check your inbox.",
            "notification_type": "Message",
            "extra": {
                "message": {
                    "id": 495,
                    "body": "Uuhvh",
                    "read": false,
                    "conversation_id": 42,
                    "user_id": 3,
                    "created_at": "2019-11-08T13:44:02.055Z",
                    "updated_at": "2019-11-08T13:44:02.055Z"
                }
            }
        },
    ]

正如您所看到的，它可以是消息、活动、合同或反馈，那么我该如何解析它，或者如何使用CodingKeys对其进行建模

Answer 1

一个简单的解决方案是创建一个名为Extra的结构，对于您拥有的每种情况，该结构都有四个可选属性。

struct Extra: Codable {
    let contract: Contract?
    let message: Message?
    let feedback: Feedback?
    let campaign: Campaign?
}

只要消息、活动、合同和反馈中的每一个都有固定的响应，那么您就应该能够为它们创建符合Codable的结构。

Answer 2

你不是指Any吧。正如您所说，extra可以是“消息、活动、合同或反馈”。它不能是UIViewController或CBPeripheral。它不是“任何东西”这是四件事中的一件。

"One of X things“是枚举：

enum Extra {
    case contract(Contract)
    case campaign(Campaign)
    case message(Message)
    case feedback(Feedback)
}

要使其可解码，我们只需查找正确的密钥：

extension Extra: Decodable {
    enum CodingKeys: CodingKey {
        case contract, campaign, message, feedback
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)

        // Try to decode each thing it could be; throw if nothing matches.
        if let contract = try? container.decode(Contract.self, forKey: .contract) {
            self = .contract(contract)
        } else if let campaign = try? container.decode(Campaign.self, forKey: .campaign) {
            self = .campaign(campaign)
        } else if let message = try? container.decode(Message.self, forKey: .message) {
            self = .message(message)
        } else if let feedback = try? container.decode(Feedback.self, forKey: .feedback) {
            self = .feedback(feedback)
        } else {
            throw DecodingError.valueNotFound(Self.self,
                                              DecodingError.Context(codingPath: container.codingPath,
                                                                    debugDescription: "Could not find extra"))
        }
    }
}

Answer 3

在本文中，您可以找到一种支持任何类型的方法，因此JSON返回的是String还是Int都无关紧要：

anycodableValue