ios - 在 iOS 上的 Swift 中从短 URL 获取完整 URL

Question

给定一个短 URL https://itun.es/us/JB7h_，如何将其扩展为完整 URL？例如https://music.apple.com/us/album/blackstar/1059043043

Answer 1

扩展

extension URL {
   func getExpandedURL() async throws -> Result<URL, Error> {
       var request = URLRequest(url: self)
       request.httpMethod = "HEAD"
       
       let (_, response) = try await URLSession.shared.data(for: request)
       
       guard let response = response as? HTTPURLResponse, response.statusCode == 200 else {
           throw URLError.unableToExpand
       }
       
       if let expandedURL = response.url {
           return .success(expandedURL)
       } else {
           throw URLError.unableToExpand
       }
   }
    
    enum URLError: Error {
        case unableToExpand
    }
}

原始演示

struct ContentView: View {
    let shortURL = URL(string: "https://itun.es/us/JB7h_")
    @State var expandedURLResult: Result<URL, Error>?
    
    var body: some View {
        Form {
            Section("Short URL") {
                Text(shortURL?.description ?? "")
            }
            
            Section("Long URL") {
                switch expandedURLResult {
                    case .some(.success(let expandedURL)):
                        Text(expandedURL.description)
                    case .none:
                        Text("Waiting")
                    case .some(.failure(let error)):
                        Text(error.localizedDescription)
                }
            }
        }
        .task {
            do {
                expandedURLResult = try await shortURL?.getExpandedURL()
            } catch {
                expandedURLResult = .failure(error)
            }
        }
    }
}