Getting an error when my app tries to download JSON - ios

Question

I finally started updating the BonusData.json file that my app uses. Now I am getting an error when it tries to load the data. The complete code is below but I am getting "JSON Download Failed", which is contained in the downloadJSON function.
If I'm reading my code right, that would mean that I'm encountering an error in the
let posts = try JSONDecoder().decode(JsonFile.self, from: data)
completed(posts.bonuses)
section, but I'm not sure how to troubleshoot that any further. What is supposed to be happening is that the app looks at the server, downloads the JSON and then saves it locally to be used to populate the UITableView. If there is no data connection, then it should not care, and just use the local saved version. Because the app is loading up blank, I'm assuming it is also not working as it is intended.
Here is the complete code:
import UIKit
import os.log
import Foundation
class BonusListViewController: UITableViewController {
var bonuses = [JsonFile.JsonBonuses]()
var filteredBonuses = [JsonFile.JsonBonuses]()
var detailViewController: BonusDetailViewController? = nil
let defaults = UserDefaults.standard
let searchController = UISearchController(searchResultsController: nil)
override func viewDidLoad() {
super.viewDidLoad()
// MARK: Search Support
searchController.searchResultsUpdater = self
searchController.obscuresBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "Enter two letter state to filter"
navigationItem.searchController = searchController
definesPresentationContext = true
// MARK: Settings Data Struct
struct Constants {
struct RiderData {
let riderNumToH = "riderNumToH"
let pillionNumToH = "pillionNumToH"
}
struct RallyData {
let emailDestinationToH = "emailDestinationToH"
}
}
//MARK: Load the bonuses
print("About to call loadBonuses")
loadBonuses { [weak self] bonuses in
self?.bonuses = bonuses ?? []
DispatchQueue.main.async {
self?.tableView.reloadData()
}
print("loadBonuses called")
}
}
// MARK: - Table View Configuration
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if isFiltering() {
print("Showing \(filteredBonuses.count) Filtered Results")
return filteredBonuses.count
}
print("Found \(bonuses.count) rows in section.")
return bonuses.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cellIdentifier = "BonusListViewCell"
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? BonusListViewCell else {
fatalError("The dequeued cell is not an instance of BonusListViewCell.")
}
// let bonus = bonuses[indexPath.row]
let bonus: JsonFile.JsonBonuses
if isFiltering() {
bonus = filteredBonuses[indexPath.row]
} else {
bonus = bonuses[indexPath.row]
}
let urlString = "http://tourofhonor.com/appimages/"+(bonus.imageName)
let url = URL(string: urlString)
cell.primaryImage.downloadedFrom(url: url!)
cell.nameLabel.text = bonus.name.capitalized
cell.bonusCodeLabel.text = bonus.bonusCode.localizedUppercase
cell.categoryLabel.text = bonus.category
cell.valueLabel.text = "\(bonus.value)"
cell.cityLabel.text = "\(bonus.city.capitalized),"
cell.stateLabel.text = bonus.state.localizedUppercase
return cell
}
// MARK: Functions
// MARK: - Fetch JSON from ToH webserver
func downloadJSON(completed: #escaping ([JsonFile.JsonBonuses]?) -> ()) {
let url = URL(string: "http://tourofhonor.com/BonusData.json")!
URLSession.shared.dataTask(with: url) { (data, response, error) in
if error == nil, let data = data {
do {
let posts = try JSONDecoder().decode(JsonFile.self, from: data)
completed(posts.bonuses)
print("URLSession did not fail")
} catch {
print("JSON Download Failed")
}
} else {
print("downloadJSON completed")
completed(nil)
}
}.resume()
}
func saveBonuses(_ bonuses: [JsonFile.JsonBonuses], to url: URL) {
try? FileManager.default.removeItem(at: url)
do {
let data = try JSONEncoder().encode(bonuses)
try data.write(to: url)
print("saveBonuses successful")
} catch {
print("Error saving bonuses to file:", error)
}
}
func loadBonusesFromFile(_ url: URL) -> [JsonFile.JsonBonuses]? {
do {
let data = try Data(contentsOf: url)
let bonuses = try JSONDecoder().decode([JsonFile.JsonBonuses].self, from: data)
print("loadBonusesFromFile successful")
return bonuses
} catch {
print("Error loading bonuses from file:", error)
return nil
}
}
func loadBonuses(completion: #escaping ([JsonFile.JsonBonuses]?) -> Void) {
let localBonusesURL = try! FileManager.default
.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
.appendingPathComponent("BonusData.json")
downloadJSON { bonuses in
if let bonuses = bonuses {
completion(bonuses)
self.saveBonuses(bonuses, to: localBonusesURL)
} else {
print("versions did not match")
completion(self.loadBonusesFromFile(localBonusesURL))
}
}
}
func searchBarIsEmpty() -> Bool {
// Returns true if the text is empty or nil
return searchController.searchBar.text?.isEmpty ?? true
}
func filterContentForSearchText(_ searchText: String, scope: String = "All") {
filteredBonuses = bonuses.filter({( bonus: JsonFile.JsonBonuses) -> Bool in
return bonus.state.localizedCaseInsensitiveContains(searchText)
})
tableView.reloadData()
}
func isFiltering() -> Bool {
return searchController.isActive && !searchBarIsEmpty()
}
// MARK: - Navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? BonusDetailViewController {
destination.bonus = bonuses[(tableView.indexPathForSelectedRow?.row)!]
}
}
}
extension BonusListViewController: UISearchResultsUpdating {
// MARK: - UISearchResultsUpdating Delegate
func updateSearchResults(for searchController: UISearchController) {
filterContentForSearchText(searchController.searchBar.text!)
}
}
The JSON is hosted here: http://tourofhonor.com/BonusData.json

Answer 1

It looks like the JSON you're trying to download is not formatted correctly. It's missing a comma between objects, and it has an extra comma at the end of the list.
There are a number of tools to validate JSON, but one accessible one is https://jsonlint.com/. If you paste the output from http://tourofhonor.com/BonusData.json there, it will highlight the formatting errors for you and give you some guidance on how to fix them.

Answer 2

I'm going to focus on what I think is the core of your question rather than the technical fix.
I'm not sure how to troubleshoot that any further.
do {
// ...
let posts = try JSONDecoder().decode(JsonFile.self, from: data)
// ...
} catch let error {
// Do something with this error.
}
decode throws details about the exception which you can do when you get the error.