swiftui_urlsession_datatask_fetch_and_display.swift

1import SwiftUI
2import Foundation
3
4struct ContentView: View {
5    @State private var dataString = "Loading..."
6
7    var body: some View {
8        Text(dataString)
9            .padding()
10            .onAppear {
11                fetchData()
12            }
13    }
14
15    func fetchData() {
16        guard let url = URL(string: "https://www.example.com") else {
17            self.dataString = "Invalid URL"
18            return
19        }
20
21        let task = URLSession.shared.dataTask(with: url) { data, response, error in
22            if let error = error {
23                DispatchQueue.main.async {
24                    self.dataString = "Error: \(error.localizedDescription)"
25                }
26                return
27            }
28
29            guard let httpResponse = response as? HTTPURLResponse,
30                  (200...299).contains(httpResponse.statusCode) else {
31                DispatchQueue.main.async {
32                    self.dataString = "Server error"
33                }
34                return
35            }
36
37            if let data = data, let string = String(data: data, encoding: .utf8) {
38                DispatchQueue.main.async {
39                    self.dataString = string
40                }
41            }
42        }
43        task.resume()
44    }
45}
46
47@main
48struct MyApp: App {
49    var body: some Scene {
50        WindowGroup {
51            ContentView()
52        }
53    }
54}