Issue while image was converted to NSData - ios

When I pick an image from gallery, I convert it to NSData & assign it a variable like so...
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
if let image = info[UIImagePickerControllerOriginalImage] as? UIImage {
UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
let data = UIImagePNGRepresentation(image) as NSData?
self.appDelegate.mydata1 = data!
}
Now I'm trying to store self.appDelegate.mydata1 to coredata like so..
guard let appDelegate = ... else {
return
}
let managedContext = ...
let entity = ...
let newProdObj = ...
newProdObj.setValue(self.appDelegate.mydata1, forKey: "imageData") //The attribute imageData in xcdatamodel is of type 'Binary Data'
do {
try managedContext.save()
self.newProductDetails.append(newProdObj as! NewProduct)
} catch let error as NSError {}
Later in another viewcontroller I'm fetching it like so...
guard let appDelegate = ...
let managedContext = ...
let fetchRequest = ...
do {
newProdDetails = try managedContext.fetch(fetchRequest as! NSFetchRequest<NSFetchRequestResult>) as! [NewProduct]
for result in newProdDetails {
print(result)
if let imageData = result.value(forKey: "imageData") as? NSData {
print(imageData)
}}
} catch let error as NSError {}
But when I try to print imageData, the control gets stuck and it goes on continuously printing numbers (which is the data) something like so...<123214 434534 345345 ...etc.
Did go through other posts with the same issue but couldn't get much help from them...

Instead of saving image data in coreData, save your images in document directory and name of those images in UserDefaults/Core Data.
And then you can fetch name from UserDefaults/Core Data and you can get the filPath for those images using this :
// Get path for any filename in document directory
func getFilePathInDocuments(fileName:String, completionHandler:#escaping(String, Bool)->()) {
let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
let url = NSURL(fileURLWithPath: path)
let fileManager = FileManager.default
let filePath = url.appendingPathComponent(fileName)?.path
if (fileManager.fileExists(atPath: filePath!)) {
completionHandler(filePath!, true)
}else{
completionHandler("File not found!",false)
}
}
If you want to know how to write your images in document directory see this : how to use writeToFile to save image in document directory?

This is not an issue. You are fetching the NSData which is an image, hence its printing the bytes in the image data which are the numbers you are talking about. Also this code is executing in the main thread, hence your app is unresponsive.
As the other answer pointed out save your image in document directory and save the relative path of the imagename in core data. This way you can fetch the name of the imagepath(relative mind you, as full document directory URL can change in app launch), and load the image from the document directory.
Also when saving the image in document directory, please do so in a background queue, using GCD or NSOperation/Operation, as if this image is large it can again block the main thread, as you are operating this in the main thread.

My suggestion is that convert image data to base64 string, and store it to CoreData. Later when you get back image, you can convert it back to NSData. Please refer this for base64 string conversion:
convert base64 decoded NSData to NSString

Related

Save and Retrieve Image File From Realm

Writing to the file system allows users to write and retrieve string, image, etc., files to and from the application on their devices.
The images I write and retrieve to the app that appear when I run the simulator, for example, are unique to that app bundle, and differ from the images I write and retrieve from my device.
When I research how to write and read image files with Realm I am told not to save the image but the path. Images are too large to store. Got it.
But the file path I am saving naturally returns data native to the specific app bundle-- or returns nil. How might I write and retrieve image files/paths to and from Realm if the file path is unique to the device(s)? Do I need a separate image array?
First View Controller
let planet = planets[indexPath.item]
cell.name.text = planet.name
cell.system.text = planet.system
let imageData = (self.getDirectoryPath() as NSString).appendingPathComponent("image")
if self.fileManager.fileExists(atPath: imageData) {
// Populates every cell with the same image
cell.earthImage.image = UIImage(contentsOfFile: imageData)
// returns nil
cell.earthImage.image = UIImage(contentsOfFile: planet.image)
}
// Retrieve directory path for image
func getDirectoryPath() -> String {
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory = paths[0]
return documentsDirectory
}
Second View Controller
let planet = Planet()
self.realm = try! Realm(configuration: config(user: SyncUser.current!))
planet.name = self.name.text!
planet.system = self.system.text!
let imageData = (self.getDirectoryPath() as NSString).appendingPathComponent("person")
if self.fileManager.fileExists(atPath: imageData) {
self.earthImage.image = UIImage(contentsOfFile: imageData)
// Why does this not write to realm?
planet.image = imageData
}
try! self.realm.write {
self.realm.add(planet)
}
Here, I am posting from the secondViewController where I would like to render these values in my collectionView in the firstViewController's numberOfItemsInSection_:) method.
Here's the model:
class Planet: Object {
#objc dynamic var name = String()
#objc dynamic var system = String()
#objc dynamic var image = String()
}

Swift 3 - Save image alternative

I need to found an alternative of this method to save images
let save = UserDefaults.standard
let imageData = UIImageJPEGRepresentation(Photo.image!, 1.0)
save.set(imageData, forKey: "Image")
save.synchronize()
if let imgData = save.object(forKey: "Image"){
let compressedJPGImage = UIImage(data: imgData as! Data)
}
and load images
let imgData = save.object(forKey: "Image")
let compressedJPGImage = UIImage(data: imgData as! Data)
Photo.image = compressedJPGImage
The problem with this method is that i have a lot of another value saved with UserDefaults.standard so it take a lot of time (5-10 minutes) when i synchronize.
It is not advisable to save large files like images to UserDefaults. UserDefaults was intended to save very small data such as a user's preferred theme color of your app. Perhaps a suitable alternative is to save your images in the document directory. Here is a function that will allow you save an image:
func saveImage(image: UIImage) -> String {
let imageData = NSData(data: UIImagePNGRepresentation(image)!)
let paths = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let docs = paths[0] as NSString
let uuid = NSUUID().uuidString + ".png"
let fullPath = docs.appendingPathComponent(uuid)
_ = imageData.write(toFile: fullPath, atomically: true)
return uuid
}
The above function will create the name of the saved image for you. If you prefer to specify the name of the image you are saving then you could do the following (but you will be responsible for ensuring the image names you specify are unique):
func saveImage(image: UIImage, withName name: String) {
let imageData = NSData(data: UIImagePNGRepresentation(image)!)
let paths = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
let docs = paths[0] as NSString
let name = name
let fullPath = docs.appendingPathComponent(name)
_ = imageData.write(toFile: fullPath, atomically: true)
}
To retrieve those images, you could pass the image name to this function:
func getImage(imageName: String) -> UIImage? {
var savedImage: UIImage?
if let imagePath = getFilePath(fileName: imageName) {
savedImage = UIImage(contentsOfFile: imagePath)
}
else {
savedImage = nil
}
return savedImage
}
Which relies on this function to work:
func getFilePath(fileName: String) -> String? {
let nsDocumentDirectory = FileManager.SearchPathDirectory.documentDirectory
let nsUserDomainMask = FileManager.SearchPathDomainMask.userDomainMask
var filePath: String?
let paths = NSSearchPathForDirectoriesInDomains(nsDocumentDirectory, nsUserDomainMask, true)
if paths.count > 0 {
let dirPath = paths[0] as NSString
filePath = dirPath.appendingPathComponent(fileName)
}
else {
filePath = nil
}
return filePath
}
Here is an example of how you would now save your images instead of UserDefaults. I am saving an image I will call "Image":
saveImage(image: Photo.image, withName name: "Image")
Here is an example of how I would retrieve the saved image:
if let theSavedImage = getImage(imageName: "Image") {
//I got the image
}
UserDefaults is a place to store a small portion of data like user preferences. UserDefaults has very limited space and can be quite slow. In your case, you mentioned it's 5-10 minutes which I doubt though.
If you want images to be stored across the sessions of the app (persistent storage), you should consider using file system (Application_Folder/Library/Cache/) or Core Data framework. You will get better performance here while accessing the image.
If images are not needed to be persisted and need to be stored for a single session of the app, you should use the imageNamed: API of UIImage class. This API loads the image once in the memory and keeps it in the system cache. For all the successive accesses it refers to the cached image only. This will increase the system cache size and application's memory footprint if you are loading too many images. Another API is imageWithContentsOfFile:. Unlike the first API, this API will always load the new image instance in memory. Memory will be deallocated once image instance is released which is not the case with the first API.

get the URL for NSData saved in CoreData

I'm saving a UIImage to Core Data. So first, I convert it to NSData, then save it.
I need to get the URL for the image after it's saved. I'm doing this because I want to schedule a local notification with an attachment, and the only way to do it, AFAIK, is to with a URL.
Here is my code:
//my image:
var myImage: UIImage?
var imageData: NSData?
if let image = myImage {
imageData = UIImageJPEGRepresentation(image, 0.5)! as NSData
}
myEntity.setValue(imageData, forKey: "image")
And that's how I should add an attachment to the notification:
UNNotificationAttachment.init(identifier: String, url: URL>, options: [AnyHashable : Any]?)
I'm saving the image and scheduling the notification manually when the user taps on a button to save the image.
Please let me know if you need extra info.
You can't get the URL. If you configured this property to use external storage then yes, technically there could be a file URL. Maybe. But there's no documented way to get it, and anyway it might not exist after all-- because the external storage setting doesn't require Core Data to use external storage, it just allows it to do so.
If you didn't use that setting then there's never any URL since the image is saved as part of the SQLIte file.
If you need a file URL for the image, save the image to a file separately from Core Data and save the file name as an entity property. Then the file URL is wherever you saved the file.
And an implementation of how I saved it and then got the URL in practice when I had the same challenge:
Swift 5:
func getImageURL(for image: UIImage?) -> URL {
let documentsDirectoryPath:NSString = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString
let tempImageName = "tempImage.jpg"
var imageURL: URL?
if let image = image {
let imageData:Data = image.jpegData(compressionQuality: 1.0)!
let path:String = documentsDirectoryPath.appendingPathComponent(tempImageName)
try? image.jpegData(compressionQuality: 1.0)!.write(to: URL(fileURLWithPath: path), options: [.atomic])
imageURL = URL(fileURLWithPath: path)
try? imageData.write(to: imageURL!, options: [.atomic])
}
return imageURL!
}

How to get image complete data while sharing it with the help of share extension?

I am using share extension in my application and I want to show image taken time while I am sharing image with share extension.Is there any way to get the time of image when we use share extension.
The timestamp is available in EXIF data stored with the images. You can get it using UIImagePickerController like this:
https://stackoverflow.com/a/33672661/4042468
On the other hand, if you have image file url, you can use import ImageIO and the below code to get all the properties of the image of which date time is one.
if let imagePath = Bundle.main.path(forResource: "test", ofType: "jpg") {
let imageURL = NSURL(fileURLWithPath: imagePath)
if let imageSource = CGImageSourceCreateWithURL(imageURL, nil) {
if let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, nil) as? [String: AnyObject] {
}
}
}
Note that there is a Exif key in which you can find timestamp.

How can I create a UIImageGIFRepresentation function?

Using Swift 3 for iOS, I am able to use cinemagraphs (animated gifs) that I download through a UIWebView without any problem. I am also trying to get them to work from the iPhone library. However, there is no way that I have found to get the data representation of a GIF stored in the library.
Someone will say that "there is no such thing as an animated gif in the library", but they would be wrong. Go to a web page in Safari, long-tap on an animated gif, and save it to your library. Then send a text message to yourself and copy in that image from the library. You'll see that the animated gif is intact and works perfectly.
My problem is that I need to copy the image from the library programmatically, and I'm not sure how to do it with no specific function built for GIFs. I would like to create the equivalent of UIImagePNGRepresentation or UIImageJPEGRespresentation, except for GIF images. Alternatively, is there a way to get an image from the library as a UIImage, so I don't have to try to convert it to data?
Here's the code I am using for other image formats:
* Edited to be latest version *
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
let origImage = info[UIImagePickerControllerOriginalImage] as! UIImage
let refURL : URL = info[UIImagePickerControllerReferenceURL] as! URL
var resizedImage: UIImage!
var ext: String!
ext = refURL.pathExtension
if ext == "GIF" {
resizedImage = origImage
} else {
resizedImage = resizeImage(origImage: origImage, ext: ext)
}
DispatchQueue.main.async(execute: { () -> Void in
self.photoUpdated(newImage: resizedImage)
})
picker.dismiss(animated: true, completion: nil)
}
For GIFs, I tried the following, using the SwiftGif project, which was not successful:
let url = Bundle.main.url(forResource: refURL.absoluteString, withExtension: "GIF")
let data = try! Data(contentsOf: url!)
let advTimeGif = UIImage.gifWithData(data)
let imageView = UIImageView(image: advTimeGif)
newImage = imageView.image
Anyone have any suggestions as to how I might get this to work? Thanks.
Edit:
I figured out a few more pieces of the puzzle. Specifically, I can get the image name and the local path to it.
let refURL : URL = info[UIImagePickerControllerReferenceURL] as! URL
let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first! as String
let localPath = URL(fileURLWithPath: documentDirectory).appendingPathComponent(imageName)
let image = info[UIImagePickerControllerOriginalImage] as! UIImage
Still can't figure out how to get it from there to Data.

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