Preview Crashed when I get data from api

Question

I'm trying to fetch data from API according to a tutorial on YouTube and I does exactly as the video but the preview somehow crashed. But when I commented out the Api().getPosts , the preview is able to resume again. If that line of code is wrong how can I write it instead?

User Interface code:

import SwiftUI

struct ContentView: View {
    @State var posts: [Post] = []
    var body: some View {
        VStack {
            List(posts) { post in
                Text(post.title)
            }
                .onAppear{
                    Api().getPosts { (posts) in
                        self.posts = posts
                    }
                }
        }//:VSTACK

    }
}
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Api Service code:

import SwiftUI

struct Post: Codable, Identifiable {
    var id = UUID()
    var title: String
    var body: String
}

class Api {
    func getPosts(completion: @escaping([Post]) -> ()) {
        guard let url = URL(string: "https://jsonplaceholder.typicode.com/posts") else { return
            print("Something occured!")
        }
        
        //CALL
        URLSession.shared.dataTask(with: url) { data, response, error in
            let posts = try! JSONDecoder().decode([Post].self, from: data!)
            DispatchQueue.main.async {
                completion(posts)
            }
            
            print(posts)
        }//:URLSESSION
        .resume()
    }
}

Answer 1

use this code for your Post model:

struct Post: Codable, Identifiable {
   // let id = UUID()  // <-- or this
    var id: Int        // <-- here
    var title: String
    var body: String
}