How to download file in swift?
IosSwiftFileDownloadIos Problem Overview
I just started learning apple swift programming for iOS coming from android. I basically can now read and manipulate swift code and also learned some common classes used in iOS swift programming but still having some confusion with the syntax and everything.
I'm trying to download file. Like, lets just say coming from this URL
var url = "http://www.mywebsite.com/myfile.pdf"
in a button click. Maybe with visual progress too
Through searching here in stackoverflow, I stumbled upon Alamofire. I might try it but I'm not sure if this is the best way for me to do it.
So, I would like to ask how and what are my options (iOS7 and iOS8) in achieving my goal. Also, pros and cons would be awesome!
Ios Solutions
Solution 1 - Ios
Example downloader class without Alamofire:
class Downloader {
class func load(URL: NSURL) {
let sessionConfig = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)
let request = NSMutableURLRequest(URL: URL)
request.HTTPMethod = "GET"
let task = session.dataTaskWithRequest(request, completionHandler: { (data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in
if (error == nil) {
// Success
let statusCode = (response as NSHTTPURLResponse).statusCode
println("Success: \(statusCode)")
// This is your file-variable:
// data
}
else {
// Failure
println("Failure: %@", error.localizedDescription);
}
})
task.resume()
}
}
This is how to use it in your own code:
class Foo {
func bar() {
if var URL = NSURL(string: "http://www.mywebsite.com/myfile.pdf") {
Downloader.load(URL)
}
}
}
Swift 3 Version
Also note to download large files on disk instead instead in memory. see `downloadTask:
class Downloader {
class func load(url: URL, to localUrl: URL, completion: @escaping () -> ()) {
let sessionConfig = URLSessionConfiguration.default
let session = URLSession(configuration: sessionConfig)
let request = try! URLRequest(url: url, method: .get)
let task = session.downloadTask(with: request) { (tempLocalUrl, response, error) in
if let tempLocalUrl = tempLocalUrl, error == nil {
// Success
if let statusCode = (response as? HTTPURLResponse)?.statusCode {
print("Success: \(statusCode)")
}
do {
try FileManager.default.copyItem(at: tempLocalUrl, to: localUrl)
completion()
} catch (let writeError) {
print("error writing file \(localUrl) : \(writeError)")
}
} else {
print("Failure: %@", error?.localizedDescription);
}
}
task.resume()
}
}
Solution 2 - Ios
Swift 4 and Swift 5 Version if Anyone still needs this
import Foundation
class FileDownloader {
static func loadFileSync(url: URL, completion: @escaping (String?, Error?) -> Void)
{
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsUrl.appendingPathComponent(url.lastPathComponent)
if FileManager().fileExists(atPath: destinationUrl.path)
{
print("File already exists [\(destinationUrl.path)]")
completion(destinationUrl.path, nil)
}
else if let dataFromURL = NSData(contentsOf: url)
{
if dataFromURL.write(to: destinationUrl, atomically: true)
{
print("file saved [\(destinationUrl.path)]")
completion(destinationUrl.path, nil)
}
else
{
print("error saving file")
let error = NSError(domain:"Error saving file", code:1001, userInfo:nil)
completion(destinationUrl.path, error)
}
}
else
{
let error = NSError(domain:"Error downloading file", code:1002, userInfo:nil)
completion(destinationUrl.path, error)
}
}
static func loadFileAsync(url: URL, completion: @escaping (String?, Error?) -> Void)
{
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsUrl.appendingPathComponent(url.lastPathComponent)
if FileManager().fileExists(atPath: destinationUrl.path)
{
print("File already exists [\(destinationUrl.path)]")
completion(destinationUrl.path, nil)
}
else
{
let session = URLSession(configuration: URLSessionConfiguration.default, delegate: nil, delegateQueue: nil)
var request = URLRequest(url: url)
request.httpMethod = "GET"
let task = session.dataTask(with: request, completionHandler:
{
data, response, error in
if error == nil
{
if let response = response as? HTTPURLResponse
{
if response.statusCode == 200
{
if let data = data
{
if let _ = try? data.write(to: destinationUrl, options: Data.WritingOptions.atomic)
{
completion(destinationUrl.path, error)
}
else
{
completion(destinationUrl.path, error)
}
}
else
{
completion(destinationUrl.path, error)
}
}
}
}
else
{
completion(destinationUrl.path, error)
}
})
task.resume()
}
}
}
Here is how to call this method :-
let url = URL(string: "http://www.filedownloader.com/mydemofile.pdf")
FileDownloader.loadFileAsync(url: url!) { (path, error) in
print("PDF File downloaded to : \(path!)")
}
Solution 3 - Ios
Here's an example that shows how to do sync & async.
import Foundation
class HttpDownloader {
class func loadFileSync(url: NSURL, completion:(path:String, error:NSError!) -> Void) {
let documentsUrl = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first as! NSURL
let destinationUrl = documentsUrl.URLByAppendingPathComponent(url.lastPathComponent!)
if NSFileManager().fileExistsAtPath(destinationUrl.path!) {
println("file already exists [\(destinationUrl.path!)]")
completion(path: destinationUrl.path!, error:nil)
} else if let dataFromURL = NSData(contentsOfURL: url){
if dataFromURL.writeToURL(destinationUrl, atomically: true) {
println("file saved [\(destinationUrl.path!)]")
completion(path: destinationUrl.path!, error:nil)
} else {
println("error saving file")
let error = NSError(domain:"Error saving file", code:1001, userInfo:nil)
completion(path: destinationUrl.path!, error:error)
}
} else {
let error = NSError(domain:"Error downloading file", code:1002, userInfo:nil)
completion(path: destinationUrl.path!, error:error)
}
}
class func loadFileAsync(url: NSURL, completion:(path:String, error:NSError!) -> Void) {
let documentsUrl = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first as! NSURL
let destinationUrl = documentsUrl.URLByAppendingPathComponent(url.lastPathComponent!)
if NSFileManager().fileExistsAtPath(destinationUrl.path!) {
println("file already exists [\(destinationUrl.path!)]")
completion(path: destinationUrl.path!, error:nil)
} else {
let sessionConfig = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)
let request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "GET"
let task = session.dataTaskWithRequest(request, completionHandler: { (data: NSData!, response: NSURLResponse!, error: NSError!) -> Void in
if (error == nil) {
if let response = response as? NSHTTPURLResponse {
println("response=\(response)")
if response.statusCode == 200 {
if data.writeToURL(destinationUrl, atomically: true) {
println("file saved [\(destinationUrl.path!)]")
completion(path: destinationUrl.path!, error:error)
} else {
println("error saving file")
let error = NSError(domain:"Error saving file", code:1001, userInfo:nil)
completion(path: destinationUrl.path!, error:error)
}
}
}
}
else {
println("Failure: \(error.localizedDescription)");
completion(path: destinationUrl.path!, error:error)
}
})
task.resume()
}
}
}
Here's how to use it in your code:
let url = NSURL(string: "http://www.mywebsite.com/myfile.pdf")
HttpDownloader.loadFileAsync(url, completion:{(path:String, error:NSError!) in
println("pdf downloaded to: \(path)")
})
Solution 4 - Ios
If you need to download only text file into String you can use this simple way, Swift 5:
let list = try? String(contentsOf: URL(string: "https://example.com/file.txt")!)
In case you want non optional result or error handling:
do {
let list = try String(contentsOf: URL(string: "https://example.com/file.txt")!)
}
catch {
// Handle error here
}
You should know that network operations may take some time, to prevent it from running in main thread and locking your UI, you may want to execute the code asynchronously, for example:
DispatchQueue.global().async {
let list = try? String(contentsOf: URL(string: "https://example.com/file.txt")!)
}
Solution 5 - Ios
Devran's and djunod's solutions are working as long as your application is in the foreground. If you switch to another application during the download, it fails. My file sizes are around 10 MB and it takes sometime to download. So I need my download function works even when the app goes into background.
Please note that I switched ON the "Background Modes / Background Fetch" at "Capabilities".
Since completionhandler was not supported the solution is not encapsulated. Sorry about that.
--Swift 2.3--
import Foundation
class Downloader : NSObject, NSURLSessionDownloadDelegate
{
var url : NSURL?
// will be used to do whatever is needed once download is complete
var yourOwnObject : NSObject?
init(yourOwnObject : NSObject)
{
self.yourOwnObject = yourOwnObject
}
//is called once the download is complete
func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL)
{
//copy downloaded data to your documents directory with same names as source file
let documentsUrl = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first
let destinationUrl = documentsUrl!.URLByAppendingPathComponent(url!.lastPathComponent!)
let dataFromURL = NSData(contentsOfURL: location)
dataFromURL?.writeToURL(destinationUrl, atomically: true)
//now it is time to do what is needed to be done after the download
yourOwnObject!.callWhatIsNeeded()
}
//this is to track progress
func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64)
{
}
// if there is an error during download this will be called
func URLSession(session: NSURLSession, task: NSURLSessionTask, didCompleteWithError error: NSError?)
{
if(error != nil)
{
//handle the error
print("Download completed with error: \(error!.localizedDescription)");
}
}
//method to be called to download
func download(url: NSURL)
{
self.url = url
//download identifier can be customized. I used the "ulr.absoluteString"
let sessionConfig = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(url.absoluteString)
let session = NSURLSession(configuration: sessionConfig, delegate: self, delegateQueue: nil)
let task = session.downloadTaskWithURL(url)
task.resume()
}
}
And here is how to call in --Swift 2.3--
let url = NSURL(string: "http://company.com/file.txt")
Downloader(yourOwnObject).download(url!)
--Swift 3--
class Downloader : NSObject, URLSessionDownloadDelegate {
var url : URL?
// will be used to do whatever is needed once download is complete
var yourOwnObject : NSObject?
init(_ yourOwnObject : NSObject)
{
self.yourOwnObject = yourOwnObject
}
//is called once the download is complete
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL)
{
//copy downloaded data to your documents directory with same names as source file
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
let destinationUrl = documentsUrl!.appendingPathComponent(url!.lastPathComponent)
let dataFromURL = NSData(contentsOf: location)
dataFromURL?.write(to: destinationUrl, atomically: true)
//now it is time to do what is needed to be done after the download
yourOwnObject!.callWhatIsNeeded()
}
//this is to track progress
private func URLSession(session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64)
{
}
// if there is an error during download this will be called
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)
{
if(error != nil)
{
//handle the error
print("Download completed with error: \(error!.localizedDescription)");
}
}
//method to be called to download
func download(url: URL)
{
self.url = url
//download identifier can be customized. I used the "ulr.absoluteString"
let sessionConfig = URLSessionConfiguration.background(withIdentifier: url.absoluteString)
let session = Foundation.URLSession(configuration: sessionConfig, delegate: self, delegateQueue: nil)
let task = session.downloadTask(with: url)
task.resume()
}}
And here is how to call in --Swift 3--
let url = URL(string: "http://company.com/file.txt")
Downloader(yourOwnObject).download(url!)
Solution 6 - Ios
Here is the Swift 4 version:
static func loadFileAsync(url: URL, completion: @escaping (String?, Error?) -> Void)
{
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let destinationUrl = documentsUrl.appendingPathComponent(url.lastPathComponent)
if FileManager().fileExists(atPath: destinationUrl.path)
{
completion(destinationUrl.path, nil)
}
else
{
let session = URLSession(configuration: URLSessionConfiguration.default, delegate: nil, delegateQueue: nil)
var request = URLRequest(url: url)
request.httpMethod = "GET"
let task = session.dataTask(with: request, completionHandler:
{
data, response, error in
if error == nil
{
if let response = response as? HTTPURLResponse
{
if response.statusCode == 200
{
if let data = data
{
if let _ = try? data.write(to: destinationUrl, options: Data.WritingOptions.atomic)
{
completion(destinationUrl.path, error)
}
else
{
completion(destinationUrl.path, error)
}
}
else
{
completion(destinationUrl.path, error)
}
}
}
}
else
{
completion(destinationUrl.path, error)
}
})
task.resume()
}
}
Solution 7 - Ios
Swift 3
you want to download file bite by bite and show in progress view so you want to try this code
import UIKit
class ViewController: UIViewController,URLSessionDownloadDelegate,UIDocumentInteractionControllerDelegate {
@IBOutlet weak var img: UIImageView!
@IBOutlet weak var btndown: UIButton!
var urlLink: URL!
var defaultSession: URLSession!
var downloadTask: URLSessionDownloadTask!
//var backgroundSession: URLSession!
@IBOutlet weak var progress: UIProgressView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let backgroundSessionConfiguration = URLSessionConfiguration.background(withIdentifier: "backgroundSession")
defaultSession = Foundation.URLSession(configuration: backgroundSessionConfiguration, delegate: self, delegateQueue: OperationQueue.main)
progress.setProgress(0.0, animated: false)
}
func startDownloading () {
let url = URL(string: "http://publications.gbdirect.co.uk/c_book/thecbook.pdf")!
downloadTask = defaultSession.downloadTask(with: url)
downloadTask.resume()
}
@IBAction func btndown(_ sender: UIButton) {
startDownloading()
}
func showFileWithPath(path: String){
let isFileFound:Bool? = FileManager.default.fileExists(atPath: path)
if isFileFound == true{
let viewer = UIDocumentInteractionController(url: URL(fileURLWithPath: path))
viewer.delegate = self
viewer.presentPreview(animated: true)
}
}
// MARK:- URLSessionDownloadDelegate
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
print(downloadTask)
print("File download succesfully")
let path = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let documentDirectoryPath:String = path[0]
let fileManager = FileManager()
let destinationURLForFile = URL(fileURLWithPath: documentDirectoryPath.appendingFormat("/file.pdf"))
if fileManager.fileExists(atPath: destinationURLForFile.path){
showFileWithPath(path: destinationURLForFile.path)
print(destinationURLForFile.path)
}
else{
do {
try fileManager.moveItem(at: location, to: destinationURLForFile)
// show file
showFileWithPath(path: destinationURLForFile.path)
}catch{
print("An error occurred while moving file to destination url")
}
}
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
progress.setProgress(Float(totalBytesWritten)/Float(totalBytesExpectedToWrite), animated: true)
}
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
downloadTask = nil
progress.setProgress(0.0, animated: true)
if (error != nil) {
print("didCompleteWithError \(error?.localizedDescription ?? "no value")")
}
else {
print("The task finished successfully")
}
}
func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController
{
return self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
use of this code you want to download file store automatically in Document Directory in your application
this code 100% Working
Solution 8 - Ios
Yes you can very easily downloads Files from the remote Url Using this code. This Code is working Fine for Me.
func DownlondFromUrl(){
// Create destination URL
let documentsUrl:URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first as URL!
let destinationFileUrl = documentsUrl.appendingPathComponent("downloadedFile.jpg")
//Create URL to the source file you want to download
let fileURL = URL(string: "https://s3.amazonaws.com/learn-swift/IMG_0001.JPG")
let sessionConfig = URLSessionConfiguration.default
let session = URLSession(configuration: sessionConfig)
let request = URLRequest(url:fileURL!)
let task = session.downloadTask(with: request) { (tempLocalUrl, response, error) in
if let tempLocalUrl = tempLocalUrl, error == nil {
// Success
if let statusCode = (response as? HTTPURLResponse)?.statusCode {
print("Successfully downloaded. Status code: \(statusCode)")
}
do {
try FileManager.default.copyItem(at: tempLocalUrl, to: destinationFileUrl)
} catch (let writeError) {
print("Error creating a file \(destinationFileUrl) : \(writeError)")
}
} else {
print("Error took place while downloading a file. Error description: %@", error?.localizedDescription);
}
}
task.resume()
}
Solution 9 - Ios
Downloading a file in Swift 5 with progress reporting, encapsulated into a copy-paste friendly protocol-accessed class:
protocol FileDownloadingDelegate: class {
func updateDownloadProgressWith(progress: Float)
func downloadFinished(localFilePath: URL)
func downloadFailed(withError error: Error)
}
class FilesDownloader: NSObject, URLSessionDownloadDelegate {
private weak var delegate: FileDownloadingDelegate?
func download(from url: URL, delegate: FileDownloadingDelegate) {
self.delegate = delegate
let sessionConfig = URLSessionConfiguration.background(withIdentifier: url.absoluteString) // use this identifier to resume download after app restart
let session = Foundation.URLSession(configuration: sessionConfig, delegate: self, delegateQueue: nil)
let task = session.downloadTask(with: url)
task.resume()
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
DispatchQueue.main.async { self.delegate?.downloadFinished(localFilePath: location) }
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
DispatchQueue.main.async { self.delegate?.updateDownloadProgressWith(progress: Float(totalBytesWritten)/Float(totalBytesExpectedToWrite)) }
}
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
guard let theError = error else { assertionFailure("something weird happened here"); return }
DispatchQueue.main.async { self.delegate?.downloadFailed(withError: theError) }
}
}
How to use it:
class MyViewController: UIViewController {
private lazy var downloader = FilesDownloader()
func downloadFile(from url: URL) {
downloader.download(from: url, delegate: self)
}
}
extension MyViewController: FileDownloadingDelegate {
func updateDownloadProgressWith(progress: Float) {
// self.downloadProgressView.setProgress(progress, animated: true)
}
func downloadFinished(tempFilePath: URL) {
print("downloaded to \(tempFilePath)")
// resave the file into your desired place using
// let dataFromURL = NSData(contentsOf: location)
// dataFromURL?.write(to: yourDesiredFileUrl, atomically: true)
}
func downloadFailed(withError error: Error) {
// handle the error
}
}
Solution 10 - Ios
iOS 13 Swift 5, 5.1
@IBAction func btnDownload(_ sender: Any) {
// file location to save download file
let destination: DownloadRequest.DownloadFileDestination = { _, _ in
var documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
documentsURL.appendPathComponent(statementPDF)
return (documentsURL, [.removePreviousFile])
}
// Alamofire to download file
Alamofire.download("http://pdf_url", to: destination).responseData { response in
hideLoader()
switch response.result {
case .success:
// write something here
if response.destinationURL != nil {
showAlertMessage(titleStr: APPNAME, messageStr: "File Saved in Documents!")
}
case .failure:
showAlertMessage(titleStr: APPNAME, messageStr: response.result.error.debugDescription)
}
}
}
Please add these permissions to info.plist, so you will able to check the download file in Document Directory
<key>UIFileSharingEnabled</key>
<true/>
<key>LSSupportsOpeningDocumentsInPlace</key>
<true/>
Solution 11 - Ios
After trying a few of the above suggestions without success (Swift versions...) I ended up using the official documentation: https://developer.apple.com/documentation/foundation/url_loading_system/downloading_files_from_websites
let downloadTask = URLSession.shared.downloadTask(with: url) {
urlOrNil, responseOrNil, errorOrNil in
// check for and handle errors:
// * errorOrNil should be nil
// * responseOrNil should be an HTTPURLResponse with statusCode in 200..<299
guard let fileURL = urlOrNil else { return }
do {
let documentsURL = try
FileManager.default.url(for: .documentDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: false)
let savedURL = documentsURL.appendingPathComponent(fileURL.lastPathComponent)
try FileManager.default.moveItem(at: fileURL, to: savedURL)
} catch {
print ("file error: \(error)")
}
}
downloadTask.resume()
Solution 12 - Ios
Try This Code only Swift 3.0 First Create NS Object File Copy this code in created File
import UIKit
class Downloader : NSObject, URLSessionDownloadDelegate {
var url : URL?
// will be used to do whatever is needed once download is complete
var obj1 : NSObject?
init(_ obj1 : NSObject)
{
self.obj1 = obj1
}
//is called once the download is complete
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL)
{
//copy downloaded data to your documents directory with same names as source file
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
let destinationUrl = documentsUrl!.appendingPathComponent(url!.lastPathComponent)
let dataFromURL = NSData(contentsOf: location)
dataFromURL?.write(to: destinationUrl, atomically: true)
//now it is time to do what is needed to be done after the download
//obj1!.callWhatIsNeeded()
}
//this is to track progress
private func URLSession(session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64)
{
}
// if there is an error during download this will be called
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?)
{
if(error != nil)
{
//handle the error
print("Download completed with error: \(error!.localizedDescription)");
}
}
//method to be called to download
func download(url: URL)
{
self.url = url
//download identifier can be customized. I used the "ulr.absoluteString"
let sessionConfig = URLSessionConfiguration.background(withIdentifier: url.absoluteString)
let session = Foundation.URLSession(configuration: sessionConfig, delegate: self, delegateQueue: nil)
let task = session.downloadTask(with: url)
task.resume()
}}
then Copy Below Code And put code in place of you want to download file
object = "http://www.mywebsite.com/myfile.pdf"
let url1 = URL(string: object!)
Downloader(url1! as NSObject).download(url: url1!)
Solution 13 - Ios
Swift 3
class ViewController: UIViewController {
var urlLink: URL!
var defaultSession: URLSession!
var downloadTask: URLSessionDownloadTask!
}
// MARK: Button Pressed
@IBAction func btnDownloadPressed(_ sender: UIButton) {
let urlLink1 = URL.init(string: "https://github.com/VivekVithlani/QRCodeReader/archive/master.zip")
startDownloading(url: urlLink!)
}
@IBAction func btnResumePressed(_ sender: UIButton) {
downloadTask.resume()
}
@IBAction func btnStopPressed(_ sender: UIButton) {
downloadTask.cancel()
}
@IBAction func btnPausePressed(_ sender: UIButton) {
downloadTask.suspend()
}
func startDownloading (url:URL) {
let backgroundSessionConfiguration = URLSessionConfiguration.background(withIdentifier: "backgroundSession")
defaultSession = Foundation.URLSession(configuration: backgroundSessionConfiguration, delegate: self, delegateQueue: OperationQueue.main)
downloadProgress.setProgress(0.0, animated: false)
downloadTask = defaultSession.downloadTask(with: urlLink)
downloadTask.resume()
}
// MARK:- URLSessionDownloadDelegate
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
print("File download succesfully")
}
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) {
downloadProgress.setProgress(Float(totalBytesWritten)/Float(totalBytesExpectedToWrite), animated: true)
}
func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
downloadTask = nil
downloadProgress.setProgress(0.0, animated: true)
if (error != nil) {
print("didCompleteWithError \(error?.localizedDescription)")
}
else {
print("The task finished successfully")
}
}
Solution 14 - Ios
You can also use a third party library that makes life easy, like Just
Just.get("http://www.mywebsite.com/myfile.pdf")
More awesome Swift stuff here https://github.com/matteocrippa/awesome-swift
Solution 15 - Ios
Background session (URLSessionDownloadTask, URLSessionUploadTask) is a part of background transfer approach which allows you to download/upload/cache files in background mode even if app was terminated. In this case when task is done iOS wakes up it (in background) and allows make some competition block in a limited time frame. It works because the downloading task is executed on nsurlsessiond daemon process[About]
Solution 16 - Ios
Use URLSessionDownloadTask to download files in background so that they can completed even if the app is terminated.
For more information see:
https://www.ralfebert.de/snippets/ios/urlsession-background-downloads/
It also shows how to implement progress monitoring for multiple tasks running in parallel:
Solution 17 - Ios
A simple, robust and elegant download manager supporting simultaneous downloads with closure syntax for progress and completion tracking. Written in Swift with Here
> And Use like it
func downloadGIF(url: String) {
let filename = url
let range: Range<String.Index> = filename.range(of:"media/")!
let lastrange: Range<String.Index> = filename.range(of:"/200w_d")!
let finalPath = String(filename[range.lowerBound..<lastrange.lowerBound])
filename[range.lowerBound..<lastrange.lowerBound]
let replaceFirstWords = finalPath.replace(string: "media/", replacement: "SocialStatus_GIF_")
let destinationUrl = "\(replaceFirstWords).gif"
let request = URLRequest(url: URL(string: imageData.bg_image)!)
viewProgress.isHidden = false
self.btnDownload.isHidden = true
setSharingButtonFalse()
let downloadKey = self.downloadManager.downloadFile(withRequest: request,
withName: destinationUrl,
shouldDownloadInBackground: true,
onProgress: { [weak self] (progress) in
self?.viewProgress.progress = CGFloat(progress)
let val = progress * 100
print("val 1 == \(val)")
DispatchQueue.main.async {
self?.viewProgress.setProgressText("\(Int(val))")
}
}) { [weak self] (error, url) in
if let error = error {
print("Error = \(error as NSError)")
self!.isDownloaded = false
self!.viewProgress.isHidden = true
self!.setSharingButtonTrue()
self?.viewProgress.setProgressText("\(0)")
print("handle error since couldn't save GIF")
} else {
if let url = url {
self!.isDownloaded = true
self!.saveGIFDownloaded()
self!.viewProgress.isHidden = true
self!.setSharingButtonTrue()
self!.createAlbum()
self!.saveGIF(url: url.absoluteURL)
}
}
}
}