Save, Check, Decode File

ContentView.swift

//
//  ContentView.swift
//  JSON
//
//  Created by Jessica Linden on 8/27/22.
//

import SwiftUI

struct Person: Codable {
    var name: String
}

struct ContentView: View {
    
    @State private var person = Person(name: "Jessie")
    @State private var result = ""
    @State var decodeResult:String = ""
    
  

    var body: some View {
        VStack(spacing: 20) {
            
            Text("Hit save then check for file")
            TextField("Name", text: $person.name)
                .padding()
      
            Text("result: \(result)")
                .padding().multilineTextAlignment(.center)
            
            HStack{
                Spacer()
                Button("Save") {
                    save(encode())
                }
                .padding()
                .background(Color.blue)
                .foregroundColor(.white)
                .cornerRadius(10)
                Spacer()
                Button(action: {
                    checkFileAvaliable()
                }) {
                    Text("Check")
                }
                .padding()
                .background(Color.blue)
                .foregroundColor(.white)
                .cornerRadius(10)
                Spacer()
            }
            
            Text(decodeResult).multilineTextAlignment(.center)
            Button(action: {
                decode()
            }) {
                Text("Decode")
            }
            .padding()
            .background(Color.blue)
            .foregroundColor(.white)
            .cornerRadius(10)
            
            
        }
        .padding()
    }
    
    
    func checkFileAvaliable(){
        do {
           let documentDirectory = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
           let fileUrl = documentDirectory.appendingPathComponent("person")
            .appendingPathExtension("txt") // you need spesify file extension
           if FileManager.default.fileExists(atPath: fileUrl.path) {
               result = "File available! You can decode File"
           } else {
               result = "File couldn' Found"
           }
       } catch {
           print(error)
       }
    }
    
    func encode(_ encoder: JSONEncoder = .init()) -> String {
        guard let encodedData = try? encoder.encode(person) else {
            fatalError("Failed to encode user data")
        }
        let jsonString = String(data: encodedData, encoding: .utf8)!
        return jsonString
    }

    func save(_ jsonString: String) {
        let url = getDocumentsDirectory()
            .appendingPathComponent("person").appendingPathExtension("txt")// you need spesify file extension check person.txt avaliable or not

        do {
            try jsonString.write(to: url, atomically: true, encoding: String.Encoding.utf8)
            print("jsonString \(jsonString)")
            print("jsonString \(url.path)")
            print("successfully wrote jsonString to url")
            result = "saved succesfully check path is avaliable or not"
        } catch {
            print("Failed to save user data")
        }
    }
    
    func decode() {
        let url = getDocumentsDirectory().appendingPathComponent("person")
            .appendingPathExtension("txt")

        guard let data = try? Data(contentsOf: url) else {
            fatalError("Failed to load url")
        }
        guard let decoded = try? JSONDecoder().decode(Person.self, from: data) else {
            fatalError("Failed to decode url")
        }
        person = decoded
        decodeResult = "Decoded Succesfully: \(person.name)"
        
    }
    
    func getDocumentsDirectory() -> URL {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let documentsDirectory = paths[0]
        return documentsDirectory
    }
}

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