How to access an array in struct Codable, Identifiable? - swift

Question

I'm trying to access a nested array in my SwiftUI code.
I have an array that looks like this:
{
"Count": 123,
"someKey": [
{
"Id": 12345,
"Images": [
28008,
28009
]
}
]
}
I'm trying to access the Images. So I came up with this code:
#ObservedObject var fetcherP = FetcherP()
public class FetcherP: ObservableObject {
#Published var sightingsP = [someKeyP]()
init(){
load()
}
func load() {
URLSession.shared.dataTask(with: request) { [self](data,response,error) in
do {
if let d = data {
let res = try JSONDecoder().decode(RootP.self, from: d)
DispatchQueue.main.async {
self.sightingsP = res.sightingsP
}
}else {
print("No Data")
}
} catch {
print (error)
}
}.resume()
}
}
and my codable:
struct RootP: Codable {
let count: Int
let someKeyP: [someKeyP]
enum CodingKeys: String, CodingKey {
case count = "count"
case someKeyP = "someKey"
}
}
struct someKeyP: Codable, Identifiable {
public var id: Int
public var images: [Int]
enum CodingKeys: String, CodingKey {
case id = "id"
case images = "images"
}
}
And this is how I try to use my code:
ForEach(fetcherP.sightingsP) {myimages in
**//How can I access the images here? I can't do foreach(myimages.images) {img in{
Text(img)
}**
}
Do I have to use double foreach? or is there any other way to do this?
any pointers would be appreciated.

Answer 1

There are a few things going wrong:
Your CodingKeys don't reflect the JSON -- case sensitivity matters
In ForEach, unless your model conforms to Hashable, you need to provide an id for it to use.
You can't provide an Int to Text -- you have to provide a String (I used string interpolation using "\(intValue)")
let jsonData = """
{
"Count": 123,
"someKey": [
{
"Id": 12345,
"Images": [
28008,
28009
]
}
]
}
""".data(using: .utf8)!
public class FetcherP: ObservableObject {
#Published var sightingsP = [someKeyP]()
init(){
load()
}
func load() {
do {
sightingsP = (try JSONDecoder().decode(RootP.self, from: jsonData)).someKeyP
} catch {
print(error)
}
}
}
struct RootP: Codable {
let count: Int
let someKeyP: [someKeyP]
enum CodingKeys: String, CodingKey {
case count = "Count"
case someKeyP = "someKey"
}
}
struct someKeyP: Codable, Identifiable {
public var id: Int
public var images: [Int]
enum CodingKeys: String, CodingKey {
case id = "Id"
case images = "Images"
}
}
struct ContentView : View {
#ObservedObject var fetcherP = FetcherP()
var body: some View {
VStack {
ForEach(fetcherP.sightingsP, id: \.id) { myImages in
ForEach(myImages.images, id: \.self) { imageNumber in
Text("\(imageNumber)")
}
}
}
}
}
Note that what I've included here is a complete, reproducible example -- it can be copied and pasted into Xcode and tested.