Filter alerts before fetching extended info.

1Weather/Network/Notifications/NWSAlertsManager.swift

@@ -157,26 +157,25 @@ public class NWSAlertsManager {
     private func fetchAllExtendedInfo(for alerts: [NWSAlert]) {
         internalQueue.addOperation { [weak self] in
             guard let self = self else { return }
-            
-            var newAlertsToFetch = [NWSAlert]()
-            
+            let localExtendedInfoBeingFetched = self.extendedInfoBeingFetched
+            let alertsToFetch = alerts.filter { (alert: NWSAlert) -> Bool in
+                alert.extendedInfo == nil && !localExtendedInfoBeingFetched.contains(alert)
+            }
             let parser = NWSAlertInfoParser()
-            for alert in alerts.filter({ $0.extendedInfo == nil }) {
-                if !self.extendedInfoBeingFetched.contains(alert) {
-                    self.extendedInfoBeingFetched.insert(alert)
-                    parser.fetchExtendedInfo(for: alert) { [weak self] (weatherMessage, extendedInfo) in
-                        DispatchQueue.main.async { [weak self] in
-                            guard let self = self else { return }
-                            guard let alertIndex = self.alerts.firstIndex(where: { $0 == alert }) else {
-                                return
-                            }
-                            self.alerts[alertIndex].weatherMessage = weatherMessage
-                            self.alerts[alertIndex].extendedInfo = extendedInfo
-                            self.internalQueue.addOperation {
-                                self.extendedInfoBeingFetched.remove(alert)
-                            }
-                            self.delegate?.extendedInfoAvailable(from: self, for: self.alerts[alertIndex])
+            for alert in alertsToFetch {
+                self.extendedInfoBeingFetched.insert(alert)
+                parser.fetchExtendedInfo(for: alert) { [weak self] (weatherMessage, extendedInfo) in
+                    DispatchQueue.main.async { [weak self] in
+                        guard let self = self else { return }
+                        guard let alertIndex = self.alerts.firstIndex(where: { $0 == alert }) else {
+                            return
+                        }
+                        self.alerts[alertIndex].weatherMessage = weatherMessage
+                        self.alerts[alertIndex].extendedInfo = extendedInfo
+                        self.internalQueue.addOperation {
+                            self.extendedInfoBeingFetched.remove(alert)
                         }
+                        self.delegate?.extendedInfoAvailable(from: self, for: self.alerts[alertIndex])
                     }
                 }
             }