Fetch data from Alamofire in background mode - ios

Question

I need to update orders from my app while app is in background.
Ok, I am using OneSignal, I can get message on didReceiveRemoteNotification and inside it, I call Alamofire to check on my api what I need to update.
The problem is when the code get to the point: Alamofire.request(url).responseJSON {(response) in it doesnt go inside, just when I open the app I can get the result.
I would like it to get the new data on background and notify users after updating, so they can click on the notification to see whats is new.
I read that Alamofire runs on a background thread by default, but the network request goes on Main thread.
So, I tried: this and this, both don't work.
I tried URLSessionConfiguration but I got Error code -999 cancelled.
So, I added sessionManager.session.finishTasksAndInvalidate() in the end of my response. The error stops, but the code still don't go inside Alamofire request.
Some of my code - didReceiveRemoteNotification on my AppDelegate:
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
fetchCompletionHandler completionHandler: #escaping (UIBackgroundFetchResult) -> Void) {
if let custom = userInfo["custom"] as? NSDictionary {
if let a = custom["a"] as? NSDictionary {
if let update = a["update"] as? NSString {
if update.isEqual(to: "Pedido") {
let strdataPedido = PedidoDAO().getMostRecentDtPedido()
if self.defaults.getDownloadInicialPedido(){
if strdataPedido != "" {
//let task = self.beginBackgroundTask()
self.loadOrdersFromLastSyncByApi(strdataPedido)
//self.endBackgroundTask(task)
}
}
}
}
}
}
loadOrdersFromLastSyncByApi function on my AppDelegate:
func loadOrdersFromLastSyncByApi(_ lastSync: String) {
let parceiroId = defaults.getParceiroId()
PedidoAPI().loadOrdersForLastSync(parceiroId, lastSync){ (dados) in
if let dadosPedidoModel = dados as? [PedidoModel] {
//do what needs to do to save new data
}
PedidoAPI().loadOrdersForLastSync function:
func loadOrdersForLastSync(_ parceiroId: String, _ lastSync: String, _ onComplete: #escaping(Any?) -> Void) {
let url = Test.basePath + "/api/orders/parceiro/\(parceiroId)/\(lastSync)"
//let queue = DispatchQueue(label: "com.test.br", qos: .background, attributes: .concurrent)
let task = self.beginBackgroundTask()
let queue = DispatchQueue.global(qos: .background)
queue.async {
Alamofire.request(url).responseJSON {(response) in
//This result its fired just when I open my app, I would like it to make everything on background
switch (response.result) {
//do what needs to send new data
}
self.endBackgroundTask(task)
Any help please?

Answer 1

Thanks for your question. So to clarify, I understood your question as the following:
You want to update users when there has been a change in their orders while the app is in background.
Follow-up Question:
Is there a reason you want to make the request from the client? Also, what data is coming in from OneSignal that you couldn't just handle on your server?
Answer:
You should handle any requests to a third party (Alamofire) on the server and then use our API to send a notification to the user with new info from the request response. I think that would be the best approach.