How can I iterate through a specific JSON item in Swift - swift

Question

I've done my best to implement other peoples similar questions from around the internet but haven't been successful. I am working on a simple app that displays the top 50 cryptocurrencies. The information I will show will be the symbol(BTC, ETH...) and price. For now I am just trying to show the symbol.
I am able to get the symbol for each coin individually by using Text(self.fetcher.publishedCoins?.data.coins[0].symbol ?? "") and changing the array index. Obviously I don't want to do that 50 times so I tried implementing ForEach but couldn't figure it out. Here's where I'm at...
ContentView.swift
import SwiftUI
import Foundation
import Combine
struct ContentView: View {
#ObservedObject var fetcher = CoinFetcher()
var body: some View {
NavigationView {
List {
//Text(self.fetcher.publishedCoins?.data.coins[0].symbol ?? "Error Updating")
//Attempting to iterate through Coin.symbol
ForEach(self.fetcher.publishedCoins?.data.coins[Coin] ?? "") { select in
Text(select.symbol)
}
}
}
}}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
LoadJSON.swift
import Foundation
public class CoinFetcher: ObservableObject {
#Published var publishedCoins: Top?
init() {
loadJSON()
}
func loadJSON() {
let url = URL(string: "https://api.coinranking.com/v1/public/coins")!
URLSession.shared.dataTask(with: url) {(data,response,error) in
do {
if let retrievedData = data {
let webData = try JSONDecoder().decode(Top.self, from: retrievedData)
print(Top.self)
DispatchQueue.main.async {
self.publishedCoins = webData
}
} else {
print("No data loaded")
}
} catch {
print ("Error here")
}
}.resume()
}
}
Coins.swift
import Foundation
// MARK: - Top
struct Top: Codable {
let status: String
let data: Data
}
// MARK: - Data
struct Data: Codable {
let coins: [Coin]
}
// MARK: - Coin
struct Coin: Codable {
let id: Int
let uuid: String
let slug: String
let symbol: String
let name: String
let confirmedSupply: Bool
let volume: Int
let marketCap: Int
let price: String
let circulatingSupply: Double
let totalSupply: Double
let approvedSupply: Bool
let change: Double
let rank: Int
let history: [String?]
enum CodingKeys: String, CodingKey {
case id, uuid, slug, symbol, name, confirmedSupply, volume, marketCap, price, circulatingSupply, totalSupply, approvedSupply, change, rank, history
}
}
Thank you for your help!

Answer 1

If you can conform Coin to Hashable:
struct Coin: Codable, Hashable { ... }
you can try the following:
NavigationView {
List {
ForEach(self.fetcher.publishedCoins?.data.coins ?? [], id:\.self) { coin in
Text(coin.symbol)
}
}
}
Note that as your data can change you need to use a dynamic ForEach loop (with an explicit id parameter)