Cannot append data to array from GET request - ios

Question

I am trying to load data from a GET request using Alamofire library in swift and cannot append data from the requests. I am trying to populate an array of orders to load into a UITableView.
I have tried a few various ways of solving this issue but nothing is working for me. I have commented out the method I tried because with 2 separate calls to fetchAll...Orders and the second call always overwrites the first and then the tableView is loaded with missing items.
class DrinkOrdersTableViewController: UITableViewController {
var orders: [Order] = []
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.title = "Current Orders"
}
override func viewWillAppear(_ animated: Bool) {
// fetchAllBeerOrders { orders in
// self.orders = orders!
// //print("Beer fetch: ", self.orders)
// self.tableView.reloadData()
// }
// fetchAllCocktailOrders { orders in
// self.orders = orders!
// //print("Cocktail fetch: ", self.orders)
// self.tableView.reloadData()
// }
fetchAllBeerOrders { orders in
self.orders.append(orders)
self.tableView.reloadData()
}
fetchAllCocktailOrders { orders in
self.orders.append(orders)
self.tableView.reloadData()
}
}
private func fetchAllCocktailOrders(completion: #escaping([Order]?) -> Void) {
Alamofire.request("http://127.0.0.1:4000/orders", method: .get)
.validate()
.responseJSON { response in
guard response.result.isSuccess else { return completion(nil) }
guard let rawInventory = response.result.value as? [[String: Any]?] else { return completion(nil) }
let currentOrders = rawInventory.compactMap { ordersDict -> Order? in
guard let orderId = ordersDict!["id"] as? String,
let orderStatus = ordersDict!["status"] as? String,
var pizza = ordersDict!["cocktail"] as? [String: Any] else { return nil }
pizza["image"] = UIImage(named: pizza["image"] as! String)
return Order(
id: orderId,
pizza: Pizza(data: pizza),
status: OrderStatus(rawValue: orderStatus)!
)
}
completion(currentOrders)
}
}
private func fetchAllBeerOrders(completion: #escaping([Order]?) -> Void) {
Alamofire.request("http://127.0.0.1:4000/orders", method: .get)
.validate()
.responseJSON { response in
guard response.result.isSuccess else { return completion(nil) }
guard let rawInventory = response.result.value as? [[String: Any]?] else { return completion(nil) }
let currentOrders = rawInventory.compactMap { ordersDict -> Order? in
guard let orderId = ordersDict!["id"] as? String,
let orderStatus = ordersDict!["status"] as? String,
var pizza = ordersDict!["pizza"] as? [String: Any] else { return nil }
pizza["image"] = UIImage(named: pizza["image"] as! String)
return Order(
id: orderId,
pizza: Pizza(data: pizza),
status: OrderStatus(rawValue: orderStatus)!
)
}
completion(currentOrders)
}
}
As of right now I am getting this error with code above: Cannot convert value of type '[Order]?' to expected argument type 'Order'. The ideal outcome of this code is to have the data that is gathered from each GET request to append to the array of Orders. I have verified that the GET requests are working and giving back the correct data. Please Help :]

Answer 1

You declared orders of type [Order] and your fetch methods compilation blocks return [Order]?. As you can see, you cannot convert value of type [Order]? to expected argument type Order when you wrote self.orders.append(orders).
To fix these, put a guard unwrap in fetch method invocations.
fetchAllBeerOrders { orders in
guard let _orders = orders else { return }
self.orders.append(_orders)
self.tableView.reloadData()
}
fetchAllCocktailOrders { orders in
guard let _orders = orders else { return }
self.orders.append(_orders)
self.tableView.reloadData()
}
Now, you have a potential memory leak in your code. fetchAllBeerOrders and fetchAllCocktailOrders are async methods with compilation blocks. You cannot use a strong reference to self here. Use weak to avoid a memory leak, like:
fetchAllBeerOrders { [weak self] orders in
guard let _orders = orders else { return }
self?.orders.append(_orders)
self?.tableView.reloadData()
}
fetchAllCocktailOrders { [weak self] orders in
guard let _orders = orders else { return }
self?.orders.append(_orders)
self?.tableView.reloadData()
}