Support for background downloads.

.swift-version

@@ -0,0 +1 @@
+4.2

SDDownloadManager.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
 s.name             = 'SDDownloadManager'
-s.version          = '1.0.3'
+s.version          = '1.1.0'
 s.summary          = 'A simple, robust and elegant download manager written in Swift'
 
 s.description      = <<-DESC
@@ -12,7 +12,9 @@ s.license          = { :type => 'MIT', :file => 'LICENSE' }
 s.author           = { 'Sagar Dagdu' => '[email protected]' }
 s.source           = { :git => 'https://github.com/SagarSDagdu/SDDownloadManager.git', :tag => s.version.to_s }
 
-s.ios.deployment_target = '11.2'
+s.swift_version = '4.2'
+s.ios.deployment_target = '10.0'
+s.framework    = 'UserNotifications'
 s.source_files = 'SDDownloadManager/Classes/*.swift'
 
 end

SDDownloadManager.xcodeproj/project.pbxproj

@@ -116,7 +116,13 @@
 				TargetAttributes = {
 					ACE3B6801F35D5BA00684BE6 = {
 						CreatedOnToolsVersion = 8.3.3;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
+						SystemCapabilities = {
+							com.apple.BackgroundModes = {
+								enabled = 0;
+							};
+						};
 					};
 				};
 			};
@@ -289,7 +295,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.sagar.thinkinfinite.SDDownloadManager;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Debug;
 		};
@@ -302,7 +308,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.sagar.thinkinfinite.SDDownloadManager;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Release;
 		};

SDDownloadManager.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

SDDownloadManager.xcodeproj/xcuserdata/sagardagdu.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Bucket
+   type = "1"
+   version = "2.0">
+</Bucket>

SDDownloadManager/AppDelegate.swift

@@ -24,15 +24,22 @@
 //  THE SOFTWARE.
 
 import UIKit
+import UserNotifications
 
 @UIApplicationMain
 class AppDelegate: UIResponder, UIApplicationDelegate {
 
     var window: UIWindow?
 
 
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
         // Override point for customization after application launch.
+        let center = UNUserNotificationCenter.current()
+        // Request permission to display alerts and play sounds.
+        center.requestAuthorization(options: [.alert, .sound])
+        { (granted, error) in
+            // Enable or disable features based on authorization.
+        }
         return true
     }
 
@@ -58,6 +65,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
         // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
     }
 
-
+    func application(_ application: UIApplication, handleEventsForBackgroundURLSession identifier: String, completionHandler: @escaping () -> Void) {
+        debugPrint("handleEventsForBackgroundURLSession: \(identifier)")
+        SDDownloadManager.shared.backgroundCompletionHandler = completionHandler
+    }
 }
 

SDDownloadManager/Classes/SDDownloadManager.swift

@@ -24,33 +24,46 @@
 //  THE SOFTWARE.
 
 import UIKit
+import UserNotifications
 
 final public class SDDownloadManager: NSObject {
 
     public typealias DownloadCompletionBlock = (_ error : Error?, _ fileUrl:URL?) -> Void
     public typealias DownloadProgressBlock = (_ progress : CGFloat) -> Void
+    public typealias BackgroundDownloadCompletionHandler = () -> Void
 
     // MARK :- Properties
 
-    var session: URLSession = URLSession()
-    var ongoingDownloads: [String : SDDownloadObject] = [:]
+    private var session: URLSession!
+    private var ongoingDownloads: [String : SDDownloadObject] = [:]
+    private var backgroundSession: URLSession!
+
+    public var backgroundCompletionHandler: BackgroundDownloadCompletionHandler?
+    public var showLocalNotificationOnBackgroundDownloadDone = true
+    public var localNotificationText: String?
 
     public static let shared: SDDownloadManager = { return SDDownloadManager() }()
 
     //MARK:- Public methods
 
-    public func dowloadFile(withRequest request: URLRequest,
+    public func downloadFile(withRequest request: URLRequest,
                             inDirectory directory: String? = nil,
                             withName fileName: String? = nil,
+                            shouldDownloadInBackground: Bool = false,
                             onProgress progressBlock:DownloadProgressBlock? = nil,
                             onCompletion completionBlock:@escaping DownloadCompletionBlock) -> String? {
 
         if let _ = self.ongoingDownloads[(request.url?.absoluteString)!] {
-            print("Already in progress")
+            debugPrint("Already in progress")
             return nil
         }
+        var downloadTask: URLSessionDownloadTask
+        if shouldDownloadInBackground {
+            downloadTask = self.backgroundSession.downloadTask(with: request)
+        } else{
+            downloadTask = self.session.downloadTask(with: request)
+        }
 
-        let downloadTask = self.session.downloadTask(with: request)
         let download = SDDownloadObject(downloadTask: downloadTask,
                                         progressBlock: progressBlock,
                                         completionBlock: completionBlock,
@@ -109,6 +122,8 @@ final public class SDDownloadManager: NSObject {
         super.init()
         let sessionConfiguration = URLSessionConfiguration.default
         self.session = URLSession(configuration: sessionConfiguration, delegate: self, delegateQueue: nil)
+        let backgroundConfiguration = URLSessionConfiguration.background(withIdentifier: Bundle.main.bundleIdentifier!)
+        self.backgroundSession = URLSession(configuration: backgroundConfiguration, delegate: self, delegateQueue: OperationQueue())
     }
 
     private func isDownloadInProgress(forUniqueKey key:String?) -> (Bool, SDDownloadObject?) {
@@ -121,6 +136,29 @@ final public class SDDownloadManager: NSObject {
         return (false, nil)
     }
 
+    private func showLocalNotification(withText text:String) {
+        let notificationCenter = UNUserNotificationCenter.current()
+        notificationCenter.getNotificationSettings { (settings) in
+            guard settings.authorizationStatus == .authorized else {
+                debugPrint("Not authorized to schedule notification")
+                return
+            }
+
+            let content = UNMutableNotificationContent()
+            content.title = text
+            content.sound = UNNotificationSound.default
+            let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 0.1,
+                                                            repeats: false)
+            let identifier = "SDDownloadManagerNotification"
+            let request = UNNotificationRequest(identifier: identifier,
+                                                content: content, trigger: trigger)
+            notificationCenter.add(request, withCompletionHandler: { (error) in
+                if let error = error {
+                    debugPrint("Could not schedule notification, error : \(error)")
+                }
+            })
+        }
+    }
 }
 
 extension SDDownloadManager : URLSessionDelegate, URLSessionDownloadDelegate {
@@ -164,6 +202,10 @@ extension SDDownloadManager : URLSessionDelegate, URLSessionDownloadDelegate {
                              didWriteData bytesWritten: Int64,
                              totalBytesWritten: Int64,
                              totalBytesExpectedToWrite: Int64) {
+        guard totalBytesExpectedToWrite > 0 else {
+            debugPrint("Could not calculate progress as totalBytesExpectedToWrite is less than 0")
+            return;
+        }
 
         if let download = self.ongoingDownloads[(downloadTask.originalRequest?.url?.absoluteString)!],
             let progressBlock = download.progressBlock {
@@ -190,4 +232,26 @@ extension SDDownloadManager : URLSessionDelegate, URLSessionDownloadDelegate {
         }
     }
 
+    public func urlSessionDidFinishEvents(forBackgroundURLSession session: URLSession) {
+        session.getTasksWithCompletionHandler { (dataTasks, uploadTasks, downloadTasks) in
+            if downloadTasks.count == 0 {
+                OperationQueue.main.addOperation({
+                    if let completion = self.backgroundCompletionHandler {
+                        completion()
+                    }
+
+                    if self.showLocalNotificationOnBackgroundDownloadDone {
+                        var notificationText = "Download completed"
+                        if let userNotificationText = self.localNotificationText {
+                            notificationText = userNotificationText
+                        }
+
+                        self.showLocalNotification(withText: notificationText)
+                    }
+
+                    self.backgroundCompletionHandler = nil
+                })
+            }
+        }
+    }
 }

SDDownloadManager/Info.plist

@@ -20,6 +20,11 @@
 	<string>1</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
+	<key>NSAppTransportSecurity</key>
+	<dict>
+		<key>NSAllowsArbitraryLoads</key>
+		<true/>
+	</dict>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
 	<key>UIMainStoryboardFile</key>
@@ -34,10 +39,5 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
-	<key>NSAppTransportSecurity</key>
-	<dict>
-		<key>NSAllowsArbitraryLoads</key>
-		<true/>
-	</dict>
 </dict>
 </plist>

SDDownloadManager/ViewController.swift

@@ -33,26 +33,37 @@ class ViewController: UIViewController {
     @IBOutlet weak var progressLabel: UILabel!
     @IBOutlet weak var finalUrlLabel: UILabel!
 
+    private let downloadManager = SDDownloadManager.shared
     let directoryName : String = "TestDirectory"
 
+    let fiveMBUrl = "https://sample-videos.com/video123/mp4/480/big_buck_bunny_480p_5mb.mp4"
+    let tenMBUrl = "https://sample-videos.com/video123/mp4/480/big_buck_bunny_480p_10mb.mp4"
+
     //MARK:- Lifecycle
 
     override func viewDidLoad() {
         super.viewDidLoad()
 
+        self.setupUI()
+        self.foregrounDownloadDemo()
+        self.backgroundDownloadDemo()
+    }
+
+    private func setupUI() {
         self.progressView.setProgress(0, animated: false)
         self.progressLabel.text = "0.0 %"
         self.finalUrlLabel.text = ""
+    }
+
+    private func foregrounDownloadDemo() {
+        let request = URLRequest(url: URL(string: self.fiveMBUrl)!)
 
-        let request = URLRequest.init(url: URL.init(string: "http://www.sample-videos.com/video/3gp/144/big_buck_bunny_144p_5mb.3gp")!)
-
-        let downloadKey = SDDownloadManager.shared.dowloadFile(withRequest: request,
-                                                               inDirectory: directoryName,
-                                                               withName: nil,
-                                                               onProgress:  { [weak self] (progress) in
-                                                                let percentage = String(format: "%.1f %", (progress * 100))
-                                                                self?.progressView.setProgress(Float(progress), animated: true)
-                                                                self?.progressLabel.text = "\(percentage) %"
+        let downloadKey = self.downloadManager.downloadFile(withRequest: request,
+                                                           inDirectory: directoryName,
+                                                           onProgress:  { [weak self] (progress) in
+                                                            let percentage = String(format: "%.1f %", (progress * 100))
+                                                            self?.progressView.setProgress(Float(progress), animated: true)
+                                                            self?.progressLabel.text = "\(percentage) %"
         }) { [weak self] (error, url) in
             if let error = error {
                 print("Error is \(error as NSError)")
@@ -65,10 +76,29 @@ class ViewController: UIViewController {
         }
 
         print("The key is \(downloadKey!)")
+    }
+
+    private func backgroundDownloadDemo() {
+        let request = URLRequest(url: URL(string: self.tenMBUrl)!)
+
+        self.downloadManager.showLocalNotificationOnBackgroundDownloadDone = true
+        self.downloadManager.localNotificationText = "All background downloads complete"
 
+        let downloadKey = self.downloadManager.downloadFile(withRequest: request, inDirectory: directoryName, withName: directoryName, shouldDownloadInBackground: true, onProgress: { (progress) in
+            let percentage = String(format: "%.1f %", (progress * 100))
+            debugPrint("Background progress : \(percentage)")
+        }) { [weak self] (error, url) in
+            if let error = error {
+                print("Error is \(error as NSError)")
+            } else {
+                if let url = url {
+                    print("Downloaded file's url is \(url.path)")
+                    self?.finalUrlLabel.text = url.path
+                }
+            }
+        }
 
+        print("The key is \(downloadKey!)")
     }
-
-
 }