I'm trying to download an image from a url in swift. This is the image url I'm trying to download, and I'm expecting it to download it to On my iPhone > testExampleApplication in the application's documents directory, but when I click the button, nothing downloads. Here's my code:
Button("Download logo image") {
let imageUrlStr = "https://media.wired.com/photos/5f2d7c2191d87e6680b80936/16:9/w_2400,h_1350,c_limit/Science_climatedesk_453801484.jpg".addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
let task = URLSession.shared.dataTask(with: URLRequest(url: URL(string: imageUrlStr)!), completionHandler: {(data, response, error) -> Void in
print("download details 1: \(data)")
print("download details 2: \(response)")
print("download details 3: \(error)")
})
// Start the download.
task.resume()
}
The Content-type in the 2nd print is image/jpeg and the error print is nil.
Am I doing something wrong in my downloading code?
In general, it's a good idea to do asynchronous tasks like this in a ObservableObject rather than the View itself.
You're already doing the downloading -- all you need to do now is save the data:
class Downloader : ObservableObject {
func downloadImage() {
let imageUrlStr = "https://media.wired.com/photos/5f2d7c2191d87e6680b80936/16:9/w_2400,h_1350,c_limit/Science_climatedesk_453801484.jpg".addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
let task = URLSession.shared.dataTask(with: URLRequest(url: URL(string: imageUrlStr)!), completionHandler: {(data, response, error) -> Void in
guard let data = data else {
print("No image data")
return
}
do {
try data.write(to: self.getDocumentsDirectory().appendingPathComponent("image.jpg"))
print("Image saved to: ",self.getDocumentsDirectory())
} catch {
print(error)
}
})
// Start the download.
task.resume()
}
private func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return paths[0]
}
}
struct ContentView : View {
#StateObject private var downloader = Downloader()
var body : some View {
Button("Download") {
downloader.downloadImage()
}
}
}
If you run this in the simulator, you can see the output to the console with the location of the directory. If you open that in Finder, you'll see your image has been saved there.
Note that to see the directory and file in the Files app, you'll need to make sure that you've set UIFileSharingEnabled to YES in your Info.plist
Firstly import Kingfisher as-
pod 'Kingfisher'
Then import it in your class as -
import Kingfisher
After that add a temporary UIImageView
let imgView = UIImageView()
imgView.kf.setImage(with: yourImageURL)
if let finalImage = imgView.image {
// finalImage is your image
}
Related
This question already has answers here:
Loading/Downloading image from URL on Swift
(39 answers)
Closed 6 months ago.
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var imageOfDog: UIImageView!
struct dataForLoading: Codable {
let message: String
}
override func viewDidLoad() {
super.viewDidLoad()
// load url
let url = "https://dog.ceo/api/breeds/image/random"
guard let loadUrl = URL(string: url) else { return }
// use loaded url in urlSession
URLSession.shared.dataTask(with: loadUrl) {(data, response, error) in
if error != nil{
print("if error printed")
print(error!.localizedDescription)
}
// decode
guard let data = data else { return }
do {
let jsonData = try JSONDecoder().decode(dataForLoading.self, from: data)
DispatchQueue.main.async {
self.imageOfDog.image = UIImage(named: jsonData.message)
}
}
catch let jsonError {
print(jsonError)
}
}.resume()
}
}
i am currentlt using. https://dog.ceo/api/breeds/image/random. this api
for loading random image
i am new to loading Api i am trying to load API through URLSession
when i run project i get below error
Random dog image[5960:196973] [framework] CUIThemeStore: No theme registered with id=0
i think i am not able to decode it properly how can i load image through API
At First Api Generates an url from image like these. {"message":"https://images.dog.ceo/breeds/elkhound-norwegian/n02091467_5985.jpg","status":"success"}
so my idea is to get first API and in Api whaterver url is coming pass it to imageview
The error occurs cause of UIImage(named: jsonData.message) . You can call this only if the image is exist in Assets Folder. You have to use UIImage(data: data)
Example of usage
if let imageURL = URL(string: jsonData.message){
if let data = try? Data(contentsOf: imageURL){
self.imageOfDog.image = UIImage(data: data)
}
}
I'm trying to download a file with SwiftyDropbox but I have problemas with the path. I have a file in mi Dropbox "prueba.txt":
Dropbox file
And this is the code that I use to download in my app.
import UIKit
import SwiftyDropbox
let clientDB = DropboxClientsManager.authorizedClient
class Controller: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
DropboxClientsManager.authorizeFromController(UIApplication.shared, controller: self, openURL: {
(url: URL) -> Void in UIApplication.shared.open(url)
})
let fileManager = FileManager.default
let directoryURL = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
let destURL = directoryURL.appendingPathComponent("/test.txt")
let destination: (URL, HTTPURLResponse) -> URL = { temporaryURL, response in
return destURL
}
clientDB?.files.download(path: "/prueba.txt", overwrite: true, destination: destination)
.response{ response, error in
if response != nil{
self.cargarDatosCliente()
//print (response)
} else if let error = error{
print (error)
}
}
.progress{ progressData in
print(progressData)
}
}
}
I try different ways but always obtain the same problem with "path", always the error is path/not_found/...
I try with other path but is the same problem.
Could you help me? Where is my mistake?
Thanks!
The problem is that "/prueba.txt" is a local file path. Dropbox expects you to give it a file path for their remote server.
You can retrieve those by using listFolder and listFolderContinue.
For example, if you want to retrieve the file paths in the root folder of your app or dropbox use:
var path = ""
clientDB?.files.listFolder(path: path).response(completionHandler: { response, error in
if let response = response {
let fileMetadata = response.entries
if response.hasMore {
// Store results found so far
// If there are more entries, you can use `listFolderContinue` to retrieve the rest.
} else {
// You have all information. You can use it to download files.
}
} else if let error = error {
// Handle errors
}
})
The fileMetadata contains the path you need. For example, you can get the path to the first file like this:
let path = fileMetadata[0].pathDisplay
If you're getting metadata about files from the API, this would be the "pathLower" property of a FileMetadata object.
client?.files.download(path: fileMetadata.pathLower!, overwrite: true, destination: destination)
.response { response, error in
if let response = response {
print(response)
} else if let error = error {
print(error)
}
}
I am new to iOS i want download image to display it is working code but here lot of code duplication
let url = URL(string: iteminfo.imageUrl!)
let urlRequest = URLRequest(url: url!)
let task = URLSession.shared.dataTask(with: urlRequest) { (data, response, error) in
if error != nil {
print(error)
}
if let data = data {
print(data)
self.imageViewItemPic.image = UIImage(data: data)
}
}
task.resume()
let url2 = URL(string: iteminfo.cookerProfilePicUrl!)
let urlRequest2 = URLRequest(url: url2!)
let task2 = URLSession.shared.dataTask(with: urlRequest2) { (data, response, error) in
if error != nil {
print(error)
}
if let data = data {
print(data)
self.imageViewCookerProfilePic.image = UIImage(data: data)
}
}
task2.resume()
So I want to reuse my code but i unfortunately i can not reach my goal. there have no error and url is correct . every time goes else statement . i am missing something but what is that ?
if let image = downlaodImage(urlImage: iteminfo.imageUrl){
print("first \(image)")
imageViewItemPic.image = image
}else{
print("first wrong......")
}
if let image = downlaodImage(urlImage: iteminfo.cookerProfilePicUrl){
print("second \(image)")
imageViewCookerProfilePic.image = image
}
else{
print("second wrong......")
}
Here is my method :
func downlaodImage(urlImage : String?) -> UIImage?{
var image : UIImage?
let url = URL(string: urlImage!)
let urlRequest = URLRequest(url: url!)
let task = URLSession.shared.dataTask(with: urlRequest) { (data, response, error) in
if let data = data {
// print(data)
image = UIImage(data: data)
}
}
task.resume()
return image
}
note: I am not sure is it best way or not . if it is not best practice feel free to guide me .
There's no need of so much hassle. You have the URL of the image so you can simply download the image from the URL. For example:
func downloadImage(imageURL: String) {
DispatchQueue.global().async {
let data = NSData.init(contentsOf: NSURL.init(string: imageURL) as! URL)
DispatchQueue.main.async {
let image = UIImage.init(data: data as! Data)
imageView.image = image
}
}
}
Edit: To reuse this code I would suggest to use extension of UIImageView. Here's an example:
extension UIImageView {
func setImageFromURL(url: String) {
DispatchQueue.global().async {
let data = NSData.init(contentsOf: NSURL.init(string: url) as! URL)
DispatchQueue.main.async {
let image = UIImage.init(data: data as! Data)
self.image = image
}
}
}
}
Use this method whenever you want to set the image of an imageView from a url like this:
self.imageViewCookerProfilePic.setImageFromURL(url: "https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQNpKmjx1w3DRDZ9IXN81-uhSUA6qL6obkOthoUkb9RZkXf5pJ8")
Dude. You should learn some staff about async and sync code.
Here is the thing. Code in you downloadImage works synchronically, so it pass you URLTask and go straight to return, there you return you image variable, that is nil.
One of the solutions in to use callback block like this:
func downloadImage(urlImage : String?, complete: ((UIImage?)->Void)? = nil){
let url = URL(string: urlImage!)
let urlRequest = URLRequest(url: url!)
let task = URLSession.shared.dataTask(with: urlRequest) { (data, response, error) in
if let data = data {
complete?(UIImage(data: data))
}
}
task.resume()
}
And then use it like this:
{ ...
downloadImage(urlImage: "", complete: { image in
if let image = image{
self.imageViewItemPic.image = image
}else{
print("no image")
}
})
...
}
You should read some tutorials about async code and web in swift. You could start with this site
downlaodImage() downloads an image asynchronously so
if let image = downlaodImage(...) { ... }
is always going to fail because program execution has continued before your response data has come back.
It would be easier just to set your images in the callback function closure of downlaodImage() as below by adding a UIImageView parameter to downlaodImage(). This way you can reduce the repetition of if else blocks by moving them to the downlaodImage function.
func downlaodImage(urlImage : String?, imageView: UIImageView) -> UIImage?{
var image : UIImage?
let url = URL(string: urlImage!)
let urlRequest = URLRequest(url: url!)
let task = URLSession.shared.dataTask(with: urlRequest) { (data, response, error) in
if let data = data {
// print(data)
if let image = UIImage(data: data) {
imageView.image = image
} else {
print("failed to load image")
}
}
}
task.resume()
return image
}
Simplified code without if/else blocks
downlaodImage(urlImage: "https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQNpKmjx1w3DRDZ9IXN81-uhSUA6qL6obkOthoUkb9RZkXf5pJ8", imageView: imageViewItemPic)
downlaodImage(urlImage: "https://www.dominos.co.nz/ManagedAssets/OLO/eStore/all/Product/NZ/P015/P015_ProductImage_Small_en_Default_20140203_105245.png", imageView: imageViewCookerProfilePic)
I'm currently displaying a video in my app and I want the user to be able to save it to its device gallery/album photo/camera roll.
Here it's what I'm doing but the video is not saved in the album :/
func downloadVideo(videoImageUrl:String)
{
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
//All stuff here
print("downloadVideo");
let url=NSURL(string: videoImageUrl);
let urlData=NSData(contentsOfURL: url!);
if((urlData) != nil)
{
let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0];
let fileName = videoImageUrl; //.stringByDeletingPathExtension
let filePath="\(documentsPath)/\(fileName)";
//saving is done on main thread
dispatch_async(dispatch_get_main_queue(), { () -> Void in
urlData?.writeToFile(filePath, atomically: true);
print("videoSaved");
})
}
})
}
I'va also look into this :
let url:NSURL = NSURL(string: fileURL)!;
PHPhotoLibrary.sharedPhotoLibrary().performChanges({
let assetChangeRequest = PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(url);
let assetPlaceHolder = assetChangeRequest!.placeholderForCreatedAsset;
let albumChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection)
albumChangeRequest!.addAssets([assetPlaceHolder!])
}, completionHandler: saveVideoCallBack)
But I have the error "Unable to create data from file (null)". My "assetChangeRequest" is nil. I don't understand as my url is valid and when I go to it with a browser, it download a quick time file.
If anyone can help me, it would be appreciated ! I'm using Swift and targeting iOS 8.0 min.
Update
Wanted to update the answer for Swift 3 using URLSession and figured out that the answer already exists in related topic here. Use it.
Original Answer
The code below saves a video file to Camera Roll. I reused your code with a minor change - I removed let fileName = videoImageUrl; because it leads to incorrect file path.
I tested this code and it saved the asset into camera roll. You asked what to place into creationRequestForAssetFromVideoAtFileURL - put a link to downloaded video file as in the example below.
let videoImageUrl = "http://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_1mb.mp4"
DispatchQueue.global(qos: .background).async {
if let url = URL(string: urlString),
let urlData = NSData(contentsOf: url) {
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0];
let filePath="\(documentsPath)/tempFile.mp4"
DispatchQueue.main.async {
urlData.write(toFile: filePath, atomically: true)
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: URL(fileURLWithPath: filePath))
}) { completed, error in
if completed {
print("Video is saved!")
}
}
}
}
}
Swift 3 version of the code from #Nimble:
DispatchQueue.global(qos: .background).async {
if let url = URL(string: urlString),
let urlData = NSData(contentsOf: url)
{
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0];
let filePath="\(documentsPath)/tempFile.mp4"
DispatchQueue.main.async {
urlData.write(toFile: filePath, atomically: true)
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: URL(fileURLWithPath: filePath))
}) { completed, error in
if completed {
print("Video is saved!")
}
}
}
}
}
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: video.url!)}) {
saved, error in
if saved {
print("Save status SUCCESS")
}
}
following #Nimble and #Yuval Tal solution, it is much more preferable to use the URLSession dataTask(with:completionHandler:) method to download a file before writing it as stated in the warning section of NSData(contentsOf:) Apple documentation
Important
Don't use this synchronous initializer to request network-based URLs.
For network-based URLs, this method can block the current thread for
tens of seconds on a slow network, resulting in a poor user
experience, and in iOS, may cause your app to be terminated.
Instead, for non-file URLs, consider using the
dataTask(with:completionHandler:) method of the URLSession
a correct implementation could be :
let defaultSession = URLSession(configuration: .default)
var dataTask: URLSessionDataTask? = nil
func downloadAndSaveVideoToGallery(videoURL: String, id: String = "default") {
DispatchQueue.global(qos: .background).async {
if let url = URL(string: videoURL) {
let filePath = FileManager.default.temporaryDirectory.appendingPathComponent("\(id).mp4")
print("work started")
self.dataTask = self.defaultSession.dataTask(with: url, completionHandler: { [weak self] data, res, err in
DispatchQueue.main.async {
do {
try data?.write(to: filePath)
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: filePath)
}) { completed, error in
if completed {
print("Saved to gallery !")
} else if let error = error {
print(error.localizedDescription)
}
}
} catch {
print(error.localizedDescription)
}
}
self?.dataTask = nil
})
self.dataTask?.resume()
}
}
}
One more advantage is that you can pause, resume and terminate your download by calling the corresponding method on dataTask: URLSessionDataTask .resume() .suspend() .cancel()
I'm trying to display and save images with Swift. On first hit, it shows the remote image on imageview, on second hit it shows blank imageview instead of it should be local image which saved on first hit.
var paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
var imagePath = paths.stringByAppendingPathComponent("images/\(id)/logo.jpg" )
var checkImage = NSFileManager.defaultManager()
if (checkImage.fileExistsAtPath(imagePath)) {
let getImage = UIImage(contentsOfFile: imagePath)
self.image?.image = getImage
} else {
dispatch_async(dispatch_get_main_queue()) {
let getImage = UIImage(data: NSData(contentsOfURL: NSURL(string: remoteImage)))
UIImageJPEGRepresentation(getImage, 100).writeToFile(imagePath, atomically: true)
self.image?.image = getImage
}
}
Edit: This one worked for me.
var paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String
var dirPath = paths.stringByAppendingPathComponent("images/\(id)" )
var imagePath = paths.stringByAppendingPathComponent("images/\(id)/logo.jpg" )
var checkImage = NSFileManager.defaultManager()
if (checkImage.fileExistsAtPath(imagePath)) {
let getImage = UIImage(contentsOfFile: imagePath)
self.image?.image = getImage
} else {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) {
checkImage.createDirectoryAtPath(dirPath, withIntermediateDirectories: true, attributes: nil, error: nil)
let getImage = UIImage(data: NSData(contentsOfURL: NSURL(string: remoteImage)))
UIImageJPEGRepresentation(getImage, 100).writeToFile(imagePath, atomically: true)
dispatch_async(dispatch_get_main_queue()) {
self.image?.image = getImage
return
}
}
}
To answer your main question, you're calling the wrong UIImage initializer. You should be calling UIImage(contentsOfFile: imagePath) in swift 2 and UIImage(contentsOf: imagePath) in swift 3.
Additionally, it looks like you're trying to do your remote fetch in the background with dispatch_async (or DispatchQueue in swift 3), but you're passing it the main queue, so you're actually blocking the main/UI thread with that. You should dispatch it to one of the background queues instead and then dispatch back to the main queue when you actually set the image in your UI:
Swift 3 :
DispatchQueue.global(qos: DispatchQoS.background.qosClass).async {
do {
let data = try Data(contentsOf: URL(string: self.remoteImage)!)
let getImage = UIImage(data: data)
try UIImageJPEGRepresentation(getImage!, 100)?.write(to: imagePath)
DispatchQueue.main.async {
self.image?.image = getImage
return
}
}
catch {
return
}
}
Swift 2 :
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) {
let getImage = UIImage(data: NSData(contentsOfURL: NSURL(string: self.remoteImage)))
UIImageJPEGRepresentation(getImage, 100).writeToFile(imagePath, atomically: true)
dispatch_async(dispatch_get_main_queue()) {
self.image?.image = getImage
return
}
}
#Rob's answer re: fetching your remote image and saving it is really the best way to do this.
Your code that dispatches NSData(contentsOfURL:) (now known as Data(contentsOf:)) to the main queue. If you're going to use that synchronous method to request remote image, you should do this on a background queue.
Also, you are taking the NSData, converting it to a UIImage, and then converting it back to a NSData using UIImageJPEGRepresentation. Don't round-trip it though UIImageJPEGRepresentation as you will alter the original payload and will change the size of the asset. Just just confirm that the data contained an image, but then write that original NSData
Thus, in Swift 3, you probably want to do something like:
DispatchQueue.global().async {
do {
let data = try Data(contentsOf: URL(string: urlString)!)
if let image = UIImage(data: data) {
try data.write(to: fileURL)
DispatchQueue.main.async {
self.imageView?.image = image
}
}
} catch {
print(error)
}
}
Even better, you should use NSURLSession because you can better diagnose problems, it's cancelable, etc. (And don't use the deprecated NSURLConnection.) I'd also check the statusCode of the response. For example:
func requestImage(_ url: URL, fileURL: URL) {
let task = URLSession.shared.dataTask(with: url) { data, response, error in
// check for fundamental network issues (e.g. no internet, etc.)
guard let data = data, error == nil else {
print("dataTask error: \(error?.localizedDescription ?? "Unknown error")")
return
}
// make sure web server returned 200 status code (and not 404 for bad URL or whatever)
guard let httpResponse = response as? HTTPURLResponse, 200 ..< 300 ~= httpResponse.statusCode else {
print("Error; Text of response = \(String(data: data, encoding: .utf8) ?? "(Cannot display)")")
return
}
// save image and update UI
if let image = UIImage(data: data) {
do {
// add directory if it doesn't exist
let directory = fileURL.deletingLastPathComponent()
try? FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
// save file
try data.write(to: fileURL, options: .atomic)
} catch let fileError {
print(fileError)
}
DispatchQueue.main.async {
print("image = \(image)")
self.imageView?.image = image
}
}
}
task.resume()
}
Note, the just-in-time creation of the folder is only necessary if you haven't created it already. Personally, when I build the original path, I'd create the folder there rather than in the completion handler, but you can do this any way you want. Just make sure the folder exists before you write the file.
Regardless, hopefully this illustrates the main points, namely that you should save the original asset and that you should do this in the background.
For Swift 2 renditions, see previous revision of this answer.