Call two API's and build structure - iOS - Swift - ios

Question

i know this is common but couldn't find answers. I thought of using dispatchGroups but not sure how I could do
Requirement: API 1 gives id, I need to construct url with that id and call another API to fetch imageUrl and then build struct with imageUrl
struct Item {
let itemId: String?
let quantity: String?
let itemImageUrl: String?
}
struct InitialDetails: Codable {
let id: String
let quantity: String
}
struct ImagePathData: Codable {
let imageUrl: String
}
API 1:
{
items: [{
id: "1",
quantity: "10"
}]
}
API 2
{
itemImagePath: "https://itemizedUrl/fish.png"
}
Code
func fetchData() -> [Item] {
URLSession.shared.dataTask(with: url) { (data, response, error) in
var items: [Items] = []
let initialData = try JSONDecoder().decode([InitialDetails].self, from: data)
for info in initialData {
var imageUrlPath: String?
let imageDataUrl = "https://itemizedUrl.com/\(info.id)"
URLSession.shared.dataTask(with: imageDataUrl) { (data, response, error) in
imageUrlPath = try JSONDecoder().decode(ImagePathData.self, from data)
}
let item = Item(itemId: initialData.id,
quantity: initialData.quantity,
itemImageUrl: imageUrlPath)
items.append(item)
}
return items
}
}
I know this is not right..pls advice how I could achieve this scenario

Answer 1

You need a completion with a dispachGroup
func fetchData(completion:#escaping([Item]) -> ()) {
var items: [Items] = []
let g = DispatchGroup()
URLSession.shared.dataTask(with: url) { (data, response, error) in
do {
let initialData = try JSONDecoder().decode([InitialDetails].self, from: data)
for info in initialData {
g.enter()
let imageDataUrl = "https://itemizedUrl.com/\(info.id)"
URLSession.shared.dataTask(with: imageDataUrl) { (data, response, error) in
do {
let imageUrlPath = try JSONDecoder().decode(ImagePathData.self, from data)
let item = Item(itemId: initialData.id,
quantity: initialData.quantity,
itemImageUrl: imageUrlPath.imageUrl)
items.append(item)
g.leave()
} catch {
print(error)
}
}
}
} catch {
print(error)
}
g.notify(queue:.main) {
completion(items)
}
}
}