[Networking with Combine and Codable] #Combine #URLSession #networking

network_with_cominbe.swift

var subscriptions = Set<AnyCancellable>()

guard let url = URL(string: "https://jsonplaceholder.typicode.com/todos/1") else { return }

// With Error handling
URLSession.shared
    .dataTaskPublisher(for: url)
    .tryMap { data, response in
        try JSONDecoder().decode(SampleData.self, from: data)
    }
    .sink(receiveCompletion: { completion in
        if case .failure(let err) = completion {
            print("Retrieving data failed with error \(err)")
        }
    }, receiveValue: { object in
        print("Retrieved object: \(object)")
    }).store(in: &subscriptions)

// Wihtout error handling
URLSession.shared
    .dataTaskPublisher(for: url)
    .map(\.data)
    .decode(type: SampleData.self, decoder: JSONDecoder())
    .sink(receiveCompletion: { completion in
        if case .failure(let err) = completion {
            print("Retrieving data failed with error \(err)")
        }
    }, receiveValue: { object in
        print("Retrieved object: \(object)")
    }).store(in: &subscriptions)

// Sending the request one time and share the outcome to the two subscribers
let networkPublisher = URLSession.shared
    .dataTaskPublisher(for: url)
    .map(\.data)
    .decode(type: SampleData.self, decoder: JSONDecoder())
    .multicast(subject: PassthroughSubject<SampleData, Error>())

networkPublisher
    .sink(receiveCompletion: { completion in
        if case .failure(let err) = completion {
            print("Sink1 Retrieving data failed with error \(err)")
        }
    }, receiveValue: { object in
        print("Sink1 Retrieved object \(object)")
    })
    .store(in: &subscriptions)

networkPublisher
    .sink(receiveCompletion: { completion in
        if case .failure(let err) = completion {
            print("Sink2 Retrieving data failed with error \(err)")
        }
    }, receiveValue: { object in
        print("Sink2 Retrieved object \(object)")
    }).store(in: &subscriptions)

networkPublisher
    .connect()
    .store(in: &subscriptions)