Need help targeting a nested json object SwiftUI *Question clarified* - json

Question

Im currently hitting a wall as I'm trying to display information from an array within a nested json object. I can't understand where I am going wrong, so any help will be greatly appreciated. **The current error I am receiving is : Fatal error: Index out of range
I believe my problem may be in regards to how I am targeting the information. I have outlined using "!! ... !!" the key areas where I believe the error is being made.
I am confused because of how the json object is nested. If I'm correct, the heiarchy for my desired target is: object(main object) -> object(DATA) -> array(newReleases) -> String(prId). With that being said Im under the impression my self.posts = results.data.newReleases would then be targeting the newReleases array directly(which I want), for it to then be printed in the contentView Text(networkManager.posts[0].prID)
Content View where the list is declared:
struct ContentView: View {
#ObservedObject var networkManager = NetworkManager()
var body: some View {
NavigationView {
List{
Text(networkManager.posts[0].prID)
}
.navigationTitle("Json Test")
}
.onAppear{
self.networkManager.fetchData()
}
}
}
Heres a photo of the JSON Data formatted.
JSON Data
This is how I have the data defined in my app:
// MARK: - Results
struct Results: Codable {
let data: DATAClass
enum CodingKeys: String, CodingKey {
case data = "DATA"
}
}
// MARK: - DATAClass
struct DATAClass: Codable {
let newReleases, exclusives, preorders, backIssues: [BackIssue]
}
// MARK: - BackIssue
struct BackIssue: Codable {
let totalcount: String
let sectionName: SectionName
let sectionLink, prID, prParentid, prTtle: String
let prPrice, prLprice, prSimg, prBimg: String
enum CodingKeys: String, CodingKey {
case totalcount
case sectionName = "section_name"
case prID = "pr_id"
case prTtle = "pr_ttle"
case prPrice = "pr_price"
}
}
}
enum SectionName: String, Codable {
case featuredNewReleases = "FEATURED_NEW_RELEASES"
case recommendedBackIssues = "RECOMMENDED_BACK_ISSUES"
case recommendedPreOrders = "RECOMMENDED_PRE_ORDERS"
}
Heres where I am attempting to decode the json object:
#Published var posts = !! [BackIssue]() !!
func fetchData() {
if let url = URL(string:" https://www.midtowncomics.com/wcfmt/services/product.svc/load-featured-sections?apiKey=&mtUser=&mtPass=&sh_id=76367&pgn=home&app_id") {
let session = URLSession(configuration: .default)
let task = session.dataTask(with: url) { data, response, error in
if error == nil {
let decoder = JSONDecoder()
if let safeData = data {
do {
let results = try decoder.decode(Results.self, from: safeData)
DispatchQueue.main.async {
!! self.posts = results.data.newReleases !!
}
} catch {
print(error)
}
}
}
}
task.resume()
}
}
}

Answer 1

Never get an item by hard-coded index in the rendering area of an SwiftUI view. If the array is empty the code crashes reliably.
Get the item safely by replacing
Text(networkManager.posts[0].prID)
with
Text(networkManager.posts.first?.prID ?? "n/a")
Better is a ForEach loop which is skipped if the array is empty.