Display JSON data in table view - json

Question

I am not able to display the JSON data on my table view I don't know why. I tried to get the JSON data but I am not able of displaying it on screen on table format.
import UIKit
class User{
var userId : Int
var id : Int
var title : String
var completed : Bool
init (userId : Int , id: Int, title : String, completed : Bool){
self.userId = userId
self.id = id
self.title = title
self.completed = completed
}
}
class ViewController: UITableViewController{
var users = [User]()
let cellId = "cellId"
override func viewDidLoad() {
super.viewDidLoad()
makeGetCall()
//makePostCall()
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return users.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
let user = users[indexPath.row]
cell.textLabel?.text = user.title
cell.detailTextLabel?.text = user.title
return cell
}
func makeGetCall(){
// users = []
let todoEndpoint: String = "http://jsonplaceholder.typicode.com/todos"
guard let url = URL(string: todoEndpoint) else {
print("Error: cannot create URL")
return
}
let urlRequest = URLRequest(url: url)
// set up the session
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
// make the request
let task = session.dataTask(with: urlRequest) {
(data, response, error) in
// check for any errors
guard error == nil else {
print("error calling GET on /todos/1")
print(error!)
return
}
// make sure we got data
guard let responseData = data else {
print("Error: did not receive data")
return
}
// parse the result as JSON, since that's what the API provides
do {
let todo = try JSONSerialization.jsonObject(with: responseData, options: .mutableLeaves)
as? NSArray
for eachUser in todo! {
let eachUsers = eachUser as! [String : AnyObject]
let userId = eachUsers["userId"] as! Int
let id = eachUsers["id"] as! Int
let title = eachUsers["title"] as! String
let completed = eachUsers["completed"] as! Bool
self.users.append(User(userId: userId, id: id, title: title, completed: completed))
print(eachUser)
DispatchQueue.main.async {
self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: self.cellId)
}
}
} catch {
print("error trying to convert data to JSON")
return
}
}
task.resume()
}
func makePostCall() {
let todosEndpoint: String = "https://jsonplaceholder.typicode.com/todos"
guard let todosURL = URL(string: todosEndpoint) else {
print("Error: cannot create URL")
return
}
var todosUrlRequest = URLRequest(url: todosURL)
todosUrlRequest.httpMethod = "POST"
let newTodo: [String: Any] = ["title": "First todo", "completed": false, "userId": 1]
let jsonTodo: Data
do {
jsonTodo = try JSONSerialization.data(withJSONObject: newTodo, options: [])
todosUrlRequest.httpBody = jsonTodo
} catch {
print("Error: cannot create JSON from todo")
return
}
let session = URLSession.shared
let task = session.dataTask(with: todosUrlRequest) {
(data, response, error) in
guard error == nil else {
print("error calling POST on /todos/1")
print(error!)
return
}
guard let responseData = data else {
print("Error: did not receive data")
return
}
// parse the result as JSON, since that's what the API provides
do {
guard let receivedTodo = try JSONSerialization.jsonObject(with: responseData,options: []) as? [String: Any] else {
print("Could not get JSON from responseData as dictionary")
return
}
print("The todo is: " + receivedTodo.description)
guard let todoID = receivedTodo["id"] as? Int else {
print("Could not get todoID as int from JSON")
return
}
print("The ID is: \(todoID)")
} catch {
print("error parsing response from POST on /todos")
return
}
}
task.resume()
}
}

Answer 1

You need to reload the table after appending the data
DispatchQueue.main.async {
self.tableView.reloadData()
}
And register line should be in viewDidLoad
self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: self.cellId)
A good way also is to use
struct User :Decodable{
let userId , id : Int
let title : String
let completed : Bool
}
users = try? JSONDecoder().decode([User].self,from:data)