Merge pull request #8 from npr/feature/issue-7-observing-network-calls

Observing network calls

RAD.xcodeproj/project.pbxproj

@@ -73,6 +73,7 @@
 		FF16FA2F20F37F3700ED572E /* OperationQueue+Background.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF16FA2E20F37F3700ED572E /* OperationQueue+Background.swift */; };
 		FF16FA3120F3897400ED572E /* URLSessionConfiguration+Configurations.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF16FA3020F3897400ED572E /* URLSessionConfiguration+Configurations.swift */; };
 		FF1A69EC219AE1D500D735F6 /* SentTimezonedDatePredicateOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF1A69EB219AE1D500D735F6 /* SentTimezonedDatePredicateOperation.swift */; };
+		FF1DA16421A7F0EA0097AFB4 /* NetworkObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF1DA16321A7F0EA0097AFB4 /* NetworkObserver.swift */; };
 		FF2193ED217F0314003417FF /* OperationIsReadyTestCase.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF2193EC217F0314003417FF /* OperationIsReadyTestCase.swift */; };
 		FF2193EF217F0528003417FF /* OperationIsExecutingTestCase.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF2193EE217F0528003417FF /* OperationIsExecutingTestCase.swift */; };
 		FF2193F1217F07E7003417FF /* OperationTestCase.swift in Sources */ = {isa = PBXBuildFile; fileRef = FF2193F0217F07E7003417FF /* OperationTestCase.swift */; };
@@ -332,6 +333,7 @@
 		FF16FA2E20F37F3700ED572E /* OperationQueue+Background.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "OperationQueue+Background.swift"; sourceTree = "<group>"; };
 		FF16FA3020F3897400ED572E /* URLSessionConfiguration+Configurations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "URLSessionConfiguration+Configurations.swift"; sourceTree = "<group>"; };
 		FF1A69EB219AE1D500D735F6 /* SentTimezonedDatePredicateOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SentTimezonedDatePredicateOperation.swift; sourceTree = "<group>"; };
+		FF1DA16321A7F0EA0097AFB4 /* NetworkObserver.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NetworkObserver.swift; sourceTree = "<group>"; };
 		FF2193EC217F0314003417FF /* OperationIsReadyTestCase.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OperationIsReadyTestCase.swift; sourceTree = "<group>"; };
 		FF2193EE217F0528003417FF /* OperationIsExecutingTestCase.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OperationIsExecutingTestCase.swift; sourceTree = "<group>"; };
 		FF2193F0217F07E7003417FF /* OperationTestCase.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OperationTestCase.swift; sourceTree = "<group>"; };
@@ -994,6 +996,7 @@
 				FFF2860620C95B3300BCFF0A /* CMTimeScale.swift */,
 				FF10A8632181D54E008DEE36 /* DatabaseFetcher.swift */,
 				FF154FB02180B60D00E60011 /* ListeningObserver.swift */,
+				FF1DA16321A7F0EA0097AFB4 /* NetworkObserver.swift */,
 				FF154FAE2180B5FF00E60011 /* Object.swift */,
 				FF0ECF432179C8AC009C5528 /* Roundable.swift */,
 			);
@@ -1447,6 +1450,7 @@
 				FF00128B21380772008740D0 /* TimeRangeBoundBuilder.swift in Sources */,
 				FF0262A421258F91007DF038 /* OutputOperation.swift in Sources */,
 				FF4A3FB8212AB58400970A97 /* RADPayload.swift in Sources */,
+				FF1DA16421A7F0EA0097AFB4 /* NetworkObserver.swift in Sources */,
 				FFA9D51D2126FE2C004EBDD0 /* FetchOperation.swift in Sources */,
 				FFA9D5232126FF90004EBDD0 /* CreateEmptyObjectPredicateOperation.swift in Sources */,
 				FFE8B56A20E6599C0038A53B /* NetworkScheduler.swift in Sources */,

RAD/AnalyticsDebuggable.swift

@@ -34,11 +34,22 @@ public protocol AnalyticsDebuggable {
     ///
     /// - Parameter observer: The observer.
     func addListeningObserver(_ observer: ListeningObserver)
-    /// Removes an observer. It is not required to call the remove.
+    /// Stop observing listening events.
+    /// It is not required to call this function.
     ///
     /// - Parameter observer: The registered observer.
     func removeListeningObserver(_ observer: ListeningObserver)
 
+    /// Add an observer to receive callbacks when requests are performed.
+    ///
+    /// - Parameter observer: The observer.
+    func addNetworkObserver(_ observer: NetworkObserver)
+    /// Stop observing network requests.
+    /// It is not required to call this function.
+    ///
+    /// - Parameter observer: The observer.
+    func removeNetworkObserver(_ observer: NetworkObserver)
+
     /// Extract RAD payload from an AVAsset. The RAD payload is formatted
     /// to be ready for displaying.
     /// The completion handler is called on main queue.

RAD/AnalyticsDebugger.swift

@@ -49,13 +49,27 @@ final class AnalyticsDebugger: AnalyticsDebuggable, PlayerObservationDelegate {
         observersContainer.append(observer)
     }
 
-    /// Unregister from listening events.
+    /// Unregister from observing listening events.
     ///
-    /// - Parameter observer: The observer which should be removed.
+    /// - Parameter observer: The observer be remove.
     func removeListeningObserver(_ observer: ListeningObserver) {
         observersContainer.remove(observer)
     }
 
+    /// Register to observe network calls.
+    ///
+    /// - Parameter observer: The observer to register.
+    func addNetworkObserver(_ observer: NetworkObserver) {
+        NetworkService.shared.addNetworkObserver(observer)
+    }
+
+    /// Unregister from observing network calls.
+    ///
+    /// - Parameter observer: The observer to remove.
+    func removeNetworkObserver(_ observer: NetworkObserver) {
+        NetworkService.shared.removeNetworkObserver(observer)
+    }
+
     func extractRADPayload(
         from asset: AVAsset,
         completion: @escaping ExtractCompletion

RAD/Model/Network/NetworkService.swift

@@ -26,6 +26,7 @@ class NetworkService: NSObject, URLSessionTaskDelegate {
 
     private var session: URLSession!
     private var tasksMap: [URLSessionTask: Completion] = [:]
+    private var observersContainer = WeakReferenceContainer<NetworkObserver>()
 
     private override init() {
         super.init()
@@ -35,12 +36,23 @@ class NetworkService: NSObject, URLSessionTaskDelegate {
             delegateQueue: OperationQueue.background)
     }
 
+    func addNetworkObserver(_ observer: NetworkObserver) {
+        observersContainer.append(observer)
+    }
+
+    func removeNetworkObserver(_ observer: NetworkObserver) {
+        observersContainer.remove(observer)
+    }
+
     func executeRequest(_ request: URLRequest, completion: Completion? = nil) {
         let task = session.dataTask(with: request)
         if let completion = completion {
             tasksMap[task] = completion
         }
         task.resume()
+        observersContainer.forEach({
+            $0?.didBeginExecutionOfUrlRequest(request)
+        })
     }
 
     // MARK: URLSessionDelegate

RAD/Model/NetworkObserver.swift

@@ -0,0 +1,27 @@
+//
+//  NetworkObserver.swift
+//  RAD
+//
+//  Copyright 2018 NPR
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+//  this file except in compliance with the License. You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software distributed under the
+//  License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+//  either express or implied. See the License for the specific language governing permissions
+//  and limitations under the License.
+//
+
+import Foundation
+
+/// A protocol which may be implemented to observe the network requests
+/// executed by framework.
+public protocol NetworkObserver: AnyObject {
+    /// Callback for each performed network request.
+    ///
+    /// - Parameter request: The request.
+    func didBeginExecutionOfUrlRequest(_ request: URLRequest)
+}