JSONDecoder with multiple date formats?

Question

I have 2 type date from api. I need to decode together. But I didn't find any solution. I need to add "yyyy-MM-dd'T'HH:mm:ssZ" format in this code. How can I do this?

    func run<T: Decodable>(_ request: URLRequest, _ decoder: JSONDecoder = JSONDecoder()) -> AnyPublisher<Response<T>, Error> {
    return URLSession.shared
        .dataTaskPublisher(for: request)
        .receive(on: DispatchQueue.main)
        .tryMap { result -> Response<T> in
            self.dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
            decoder.dateDecodingStrategy = .formatted(self.dateFormatter)
            let value = try decoder.decode(T.self, from: result.data)
            return Response(value: value, response: result.response)
        }
        .eraseToAnyPublisher()
}

Answer 1

Another approach is a custom dateDecodingStrategy with ISO8601DateFormatter which is able to specify the date format depending on the given string

func run<T: Decodable>(_ request: URLRequest, _ decoder: JSONDecoder = JSONDecoder()) -> AnyPublisher<Response<T>, Error> {
return URLSession.shared
    .dataTaskPublisher(for: request)
    .receive(on: DispatchQueue.main)
    .tryMap { result -> Response<T> in
        decoder.dateDecodingStrategy = .custom { decoder -> Date in
            let container = try decoder.singleValueContainer()
            let dateFormatter = ISO8601DateFormatter()
            let dateString = try container.decode(String.self)
            if !dateString.hasSuffix("Z") {                            
                dateFormatter.formatOptions.remove(.withTimeZone) 
            }
            if let isoDate = dateFormatter.date(from: dateString) {
                return isoDate 
            } else {
                throw DecodingError.dataCorruptedError(in: container, debugDescription: "Wrong Date Format")
            }
        }
        let value = try decoder.decode(T.self, from: result.data)
        return Response(value: value, response: result.response)
    }
    .eraseToAnyPublisher()
}

Answer 2

You can implement custom decoding behavior by implementing init(from decoder: Decoder)

https://developer.apple.com/documentation/foundation/archives_and_serialization/encoding_and_decoding_custom_types