SwiftUI parse Multilayer JSON Data from URL and build list - swiftui

Question

First an information: I am actually on the way learning swiftUI, I'm a total newbie. For my first project i decided to create a small app that loads articles from a joomla website. My API will respond to a query in the following structure:
{
"source": "my AppConnector for Joomla!",
"offset": 0,
"count": 0,
"results": [
{
"id": "8",
"title": "Article 1",
...
},
{
"id": "8",
"title": "Article 2",
...
}
]
}
In the future the API will return more complex structures but actually i'm struggling already with that one. All swiftUI examples & videos i've found are just explaining how to retreive an array of items or are to old and shows depreacet code examples (with the one-dimensional examples i have already successfully created a list view of items but that's not what i want).
I've created the following structs:
struct Welcome: Codable {
let source: String
let offset, count: Int
let results: [Result]
}
// MARK: - Result
struct Result: Codable {
let id, title, alias, introtext: String
let fulltext, state, catid, created: String
let createdBy, createdByAlias, modified, modifiedBy: String
let checkedOut, checkedOutTime, publishUp, publishDown: String
let images, urls, attribs, version: String
let ordering, metakey, metadesc, access: String
let hits, metadata, featured, language: String
let xreference, note, slug, articleID: String
let introImage, fullImage: String
}
and the following fetcher:
import Foundation
import SwiftUI
import Combine
public class ArticlesFetcher: ObservableObject {
#Published var articles = [Welcome]()
init(){
load()
}
func load() {
let url = URL(string: "https://nx-productions.ch/index.php/news")! //This is a public demo url feel free to check the jsondata (SecurityToken temporary disabled)
URLSession.shared.dataTask(with: url) {(data,response,error) in
do {
if let d = data {
let decodedLists = try JSONDecoder().decode([Welcome].self, from: d)
DispatchQueue.main.async {
self.articles = decodedLists
}
}else {
print("No Data")
}
} catch {
print ("Error")
}
}.resume()
}
}
My view looks like this:
struct ContentView: View {
#ObservedObject var fetcher = ArticlesFetcher()
var body: some View {
VStack {
List(fetcher.articles.results) { article in
VStack (alignment: .leading) {
Text(article.title)
Text(article.articleId)
.font(.system(size: 11))
.foregroundColor(Color.gray)
}
}
}
}
}
What i don't understand is the view part - i am not able to point into the fields, with the example above i get compiler errors like "Value of type '[Welcome]' has no member 'results'" or "Value of type 'Int' has no member 'title'"
I think i may just not understand something aboutmy structure or how to loop through it.
Thanks for any advise.

Answer 1

The JSON starts with a { so it's a dictionary. And the type of articles is wrong.
Replace
#Published var articles = [Welcome]()
with
#Published var articles = [Result]()
and replace
let decodedLists = try JSONDecoder().decode([Welcome].self, from: d)
DispatchQueue.main.async {
self.articles = decodedLists
}
with
let decodedLists = try JSONDecoder().decode(Welcome.self, from: d)
DispatchQueue.main.async {
self.articles = decodedLists.results
}
Finally but not related replace meaningless
print ("Error")
with
print(error)