I have been unable to find enough documentation to get started on a Photos Project extension (available in High Sierra).
How do I retrieve what a user has selected (like how Apple does it with their Prints extension), and display that in my extension's view?
I think you just want to look at PHProjectInfo which is passed to you in beginProject. That's where you get the real context of what was selected. For example:
let sections = projectInfo.sections
guard let firstContentSection = sections.first(where: { section in section.sectionType == .content }),
let firstContents = firstContentSection.sectionContents.first
You then need to convert the cloud identifiers to local ones for fetching:
localIdentifiers = context.photoLibrary.localIdentifiers(for: cloudIdentifiers)
From there, you can fetch the actual PHAssets:
let fetchResult = PHAsset.fetchAssets(withLocalIdentifiers: localIdentifiers, options: nil)
For any PHAsset, when you want the image you want to use PHImageManager:
imageManager.requestImage(for: asset, targetSize: targetSize, contentMode: PHImageContentMode.aspectFit, options: nil)
Related
When I use PHImageManager() to retrieve an image from the photo library, the image is converted from a jpeg image to a png image, and the image is degraded.
How can I retrieve the image without image degradation?
Is it a standard specification that the extension is changed from jpeg to png?
If anyone knows, please respond.
Here is a sample code I made.
img is returned as png.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let assets: PHFetchResult = PHAsset.fetchAssets(with: .image, options: nil)
let mg: PHImageManager = PHImageManager()
guard let asset = assets.lastObject else {
return
}
let options = PHImageRequestOptions()
options.isNetworkAccessAllowed = true
options.deliveryMode = .highQualityFormat
mg.requestImage(for: asset, targetSize: PHImageManagerMaximumSize, contentMode: .aspectFit, options: options, resultHandler: { image, info in
let img = image
})
}
}
When requesting a high quality image, the result handler of requestImage may be called initially with a low quality version of the image, then later called again with the high quality version.
You can check this by inspecting the PHImageResultIsDegradedKey of the info dictionary parameter of the result handler, for example:
mg.requestImage(for: asset, targetSize: PHImageManagerMaximumSize, contentMode: .aspectFit, options: options, resultHandler: { image, info in
if info?[PHImageResultIsDegradedKey] as? Bool == true {
print("Degraded image returned, will wait for high quality image")
return
}
let img = image
})
From the documentation for PHImageManager.requestImage:
[...] Photos may call your result handler block more than once. Photos first calls the block to provide a low-quality image suitable for displaying temporarily while it prepares a high-quality image. (If low-quality image data is immediately available, the first call may occur before the method returns.) When the high-quality image is ready, Photos calls your result handler again to provide it. If the image manager has already cached the requested image at full quality, Photos calls your result handler only once. The PHImageResultIsDegradedKey key in the result handler’s info parameter indicates when Photos is providing a temporary low-quality image.
I tried to do like this, but it does not work, the text is not copied
if let urlScheme = URL(string: "instagram-stories://share") {
if UIApplication.shared.canOpenURL(urlScheme) {
let imageData: Data = UIImage(systemName:"pencil.circle.fill")!.pngData()!
let items:[String: Any] = ["public.utf8-plain-text": "text","com.instagram.sharedSticker.backgroundImage": imageData]
UIPasteboard.general.setItems([items])
UIApplication.shared.open(urlScheme, options: [:], completionHandler: nil)
}}
I would really appreciate any advice
2 things I can think of:
First, I am not sure the below data in your array can be properly handled by pastebin
let items:[String: Any] = ["public.utf8-plain-text": "text","com.instagram.sharedSticker.backgroundImage": imageData]
Next it seems that the activity of sharing causes data in the PasteBoard to be lost so I can offer the solution to put valid data into the PasteBoard (I am using string for example, you can use something else" from the completion handler of your sharing action, something like this might solve it:
UIApplication.shared.open(urlScheme, options: [:]) { (_) in
UIPasteboard.general.string =
"click on the screen until the paste button appears: https://google.com"
}
EDIT
It seems your set up was right and on reading the docs, IG stories should handle the Paste automatically as it seems to check the pasteboard when you execute this url scheme: instagram-stories://share - so it seems IG checks the pasteboard and performs a paste programmatically and that is why the pasteboard gets cleared.
Maybe because the image you choose is black on the black instagram background, it seems nothing is shared but with some proper image the result seems fine.
The other thing I noticed after reading their docs, they do not allow you to set captions anymore, I cannot find this key anymore public.utf8-plain-text
Another idea I can offer to share text is to convert text into an image and add it as a sticker as the sticker layer comes on top of the background image layer.
You can find multiple ways to convert text to an image and it is not relevant to your solution, here is one way I used
So bringing the code together, I have this:
// Just an example to convert text to UIImage
// from https://stackoverflow.com/a/54991797/1619193
extension String {
/// Generates a `UIImage` instance from this string using a specified
/// attributes and size.
///
/// - Parameters:
/// - attributes: to draw this string with. Default is `nil`.
/// - size: of the image to return.
/// - Returns: a `UIImage` instance from this string using a specified
/// attributes and size, or `nil` if the operation fails.
func image(withAttributes attributes: [NSAttributedString.Key: Any]? = nil, size: CGSize? = nil) -> UIImage? {
let size = size ?? (self as NSString).size(withAttributes: attributes)
return UIGraphicsImageRenderer(size: size).image { _ in
(self as NSString).draw(in: CGRect(origin: .zero, size: size),
withAttributes: attributes)
}
}
}
// Then inside some function of yours
func someFunction() {
if let urlScheme = URL(string: "instagram-stories://share") {
if UIApplication.shared.canOpenURL(urlScheme) {
let imageData: Data = UIImage(named: "bg")!.pngData()!
let textImage: Data = "Shawn Test".image(withAttributes: [.foregroundColor: UIColor.red,
.font: UIFont.systemFont(ofSize: 30.0)],
size: CGSize(width: 300.0, height: 80.0))!.pngData()!
let items = ["com.instagram.sharedSticker.stickerImage": textImage,
"com.instagram.sharedSticker.backgroundImage": imageData]
UIPasteboard.general.setItems([items])
UIApplication.shared.open(urlScheme, options: [:], completionHandler: nil)
}
}
}
I then see this in IG stories with correct background and text as sticker which can be moved.
Only downside of using the sticker is you cannot edit the text in Instagram.
Regarding the research looks like the only one workaround to have a text/link copied in the Pasteboard when IG Story is opened is to use:
UIPasteboard.general.string = "your link here"
but you need to do it with a delay - like:
UIApplication.shared.open(instagramStoryURL, options: [:]) { success in
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
UIPasteboard.general.string = "your link here"
}
}
to try to be sure the it won't override:
UIPasteboard.general.items
that contains, for example, "com.instagram.sharedSticker.stickerImage"
Also, please be careful with a delay - as iOS has some privacy restrictions to allow copy data to UIPasteboard when the App is in background (based on the tests we have less than 1 second to do that.
It means that you could try to copy the link this way:
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(appMovedToBackground), name: UIApplication.willResignActiveNotification, object: nil)
}
#objc func appMovedToBackground() {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.75) {
UIPasteboard.general.string = "your link here"
}
}
Anyway, there is one obvious inconvenience.
Each time you try to call "instagram-stories://share" API the first time - you face a system popup that asks for the permisson to allow to open Instagram and also to allow paste the data.
In this case we'll lose, for example, "com.instagram.sharedSticker.stickerImage" data as by the delay it will be overrided by UIPasteboard.general.string.
But we could to make it expected for users by any UI/UX solution with instructions/guide.
i have an app that works with API JSON response. Just retrieving a simple array of items. Each item has an url with a high-res image. I'm using Kingfisher to get this images and resize to my ImageView size (that placed on my MainView)
//MainViewController
itemImageMainVC.kf.setImage(
with: URL(string: itemModel.artImage),
options: [
.processor(DownsamplingImageProcessor(size: itemImageMainVC.bounds.size) >> RoundCornerImageProcessor(cornerRadius: 16, targetSize: itemImageMainVC.bounds.size)),
.scaleFactor(UIScreen.main.scale),
.transition(.fade(0.2)),
.cacheOriginalImage
])
Everything is fine here, i've got my images on my MainView inside TableView, and they cached well. BUT! If i try to open and display the same images, but with different sizes on the SecondView, i see the same transition animation on the SecondView, so i guess that they started to download again when they shouldn't.
//SecondViewController
itemImageSecondVC.kf.setImage(
with: URL(string: itemModel.artImage),
options: [
.processor(DownsamplingImageProcessor(size: itemImageSecondVC.bounds.size) >> RoundCornerImageProcessor(cornerRadius: 16, targetSize: itemImageSecondVC.bounds.size)),
.scaleFactor(UIScreen.main.scale),
.transition(.fade(0.2)),
.cacheOriginalImage
])
itemImageMainVC and itemImageSecondVC have different sizes.
What i'm doing wrong? I just want to download/display images on the MainView and instantly show them when i open SecondView, without re-downloading
Lets try to use the cacheKey, it should be the last path component (or event the absoluteUrlString) from your image url or something that is unique.
let resource = ImageResource(downloadURL: url, cacheKey: url.lastPathComponent)
self.imageView.kf.setImage(with: resource, placeholder: UIImage(named: "placeholder-image"), options: nil, progressBlock: nil) { (result) in
switch result {
case .success(_):
// Success case
case .failure(_):
// Failed case
}
}
My code as below. It is sending duplicated photos 1) high quality and 2) low quality. Just want to understand why this library is doing that ?
PHImageManager.default().requestImage(for: asset, targetSize: size, contentMode: .aspectFit, options: nil) { result, info in
guard let image = result else {
return
}
self.sendPhoto(image)
}
FIXed by to force the options to send a quality
fileprivate func imageRequestOptions() -> PHImageRequestOptions {
let requestOption = PHImageRequestOptions()
requestOption.deliveryMode = .highQualityFormat
return requestOption
}
PHImageManager.default().requestImage(for: asset, targetSize: size, contentMode: .aspectFit, options: self.imageRequestOptions()) { result, info in
guard let image = result else {
return
}
self.sendPhoto(image)
print("sendPhoto iOS 11.0 * asset")
}
From the document of Apple
For an asynchronous request, Photos may call your result handler block more than once. Photos first calls the block to provide a low-quality image suitable for displaying temporarily while it prepares a high-quality image. (If low-quality image data is immediately available, the first call may occur before the method returns.) When the high-quality image is ready, Photos calls your result handler again to provide it. If the image manager has already cached the requested image at full quality, Photos calls your result handler only once. The PHImageResultIsDegradedKey key in the result handler’s info parameter indicates when Photos is providing a temporary low-quality image.
You can use this method for both photo and video assets—for a video asset, an image request provides a thumbnail image or poster frame.
Maybe this is business of them. I think we should note with this case
I call the function. Alright
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
let index = viewControllers?.index(of: viewController)
if index == 2 {
let layout = UICollectionViewFlowLayout()
let photoSelectorController = PhotoSelectorController(collectionViewLayout: layout)
let navController = UINavigationController(rootViewController: photoSelectorController)
present(navController, animated: true, completion: nil)
return false }
return true
}
Photos not showing on first time
I have all of the right things asking for permission and everything..
I then call for the images with these functions. It works, but the second time I hit the button after canceling posting a post..
I'm not sure how to get the images from the library for the first call.
After that it works like a charm, but most users have been telling me this isn't a good experience , if they have to try twice.
I'm trying to reduce friction in the app usage.
It should show the pictures right after the user "Allows" the app access to the pictures so they can post, but I'm not sure what I'm doing wrong for it to show the pictures soon as someone grants access.
var selectedImage: UIImage?
var images = [UIImage]()
var assets = [PHAsset]()
fileprivate func assetsFetchOptions() -> PHFetchOptions {
let fetchOptions = PHFetchOptions()
fetchOptions.fetchLimit = 100
let sortDescriptor = NSSortDescriptor(key: "creationDate", ascending: false)
fetchOptions.sortDescriptors = [sortDescriptor]
return fetchOptions
}
fileprivate func fetchPhotos() {
let allPhotos = PHAsset.fetchAssets(with: .image, options: assetsFetchOptions())
DispatchQueue.global(qos: .background).async {
allPhotos.enumerateObjects { (asset, count, stop) in
print(asset)
let imageManager = PHImageManager.default()
let targetSize = CGSize(width: 200, height: 200)
let options = PHImageRequestOptions()
options.isSynchronous = true
imageManager.requestImage(for: asset, targetSize: targetSize, contentMode: .aspectFit, options: options, resultHandler: { (image, info) in
if let image = image {
self.images.append(image)
self.assets.append(asset)
if self.selectedImage == nil {
self.selectedImage = image
}
}
if count == allPhotos.count - 1 {
DispatchQueue.main.async {
self.collectionView?.reloadData()
}
}
})
}
}
}
If you fetchAssets before the user grants privacy access to your app, you'll get a PHFetchResult that's empty.
However, if before making that fetch you register as a photo library observer, you'll get a photoLibraryDidChange callback as soon as the user approves privacy access for the app... from that callback you can access an updated version of your original fetch result (see changeDetails(for:)) that has all of the assets your fetch should have found. Then you can tell your UI to update and display those assets. (This is how Apple's canonical PhotoKit example code works.)
Also, once you have a populated fetch result, please don't request thumbnails for the whole thing the way you're doing.
Users commonly have photo libraries with tens of thousands of assets, many of which are in iCloud and not on the local device. If you synchronously get all thumbnails, you'll take forever, use tons of memory and CPU resources, and generate all kinds of network traffic (slowing things down even more) for resources your user may never see.
PhotoKit is designed to allow easy use in conjunction with UI elements like UICollectionView. A collection view only loads cells that are currently (or soon to be) on screen, even if you've told it you have zillions of items in your collection — similarly, you can request thumbnails only for assets that are visible in your collection view. Wherever you have your per-cell UI setup logic is where you should have your PHImageManager request. (Again, this is what the canonical PhotoKit example code does.)
You can optimize even further by "preheating" the thumbnail fetch/generation process for assets that are soon to be onscreen. And then by managing your "preheating" to cancel such work in progress when further UI updates (e.g. fast scrolling of large collection) make it unnecessary. PHCachingImageManager does this. (And yet again, it's what the canonical Apple sample does. Actually, that sample's a bit out of date, and as such does more work than it needs to on this front — it does its own calculation of what cells are just outside the scroll rect, but since iOS 10 the UICollectionViewDataSourcePrefetching protocol manages that for you.)