Save image to library from URL, rename, and share it using Swift - ios

Question

I want to share images to Instagram from my own iOS app and I am using Kingfisher throughout the project to download and cache images and show them in UIImageViews but this time I want to do something a little bit different.
Basically, I am getting a response from an API with the url of an image and I want to
Download the image to the library using the URL
There is a bunch of questions on this for objective-C using
UIImageWriteToSavedPhotosAlbum
but I am using Swift.
Rename it with .igo extension (instagram exclusive)
Not sure how to go about this, would depend on number 1.
Then I could share it doing something like
let image = UIImage(named: "downloadedImage")
let objectsToShare: [AnyObject] = [ image! ]
let activityViewController = UIActivityViewController(activityItems: objectsToShare, applicationActivities: nil)
activityViewController.popoverPresentationController?.sourceView = self.view
activityViewController.excludedActivityTypes = [ UIActivityTypeAirDrop, UIActivityTypePostToFacebook ]
self.presentViewController(activityViewController, animated: true, completion: nil)
or I could do it using the instagram hooks:
instagram://library?LocalIdentifier=\(localID)
Documentation on this is scarce specially for Swift. How can I go about this? a push in the right direction is all I need.

Answer 1

It sounds like you already know how to use Kingfisher and retrieving the UIImage from the URL. So what i'm about to provide is information for saving the image to the documents directory and retrieving it to share.
Retrieve the correct directory URL
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}
Saving an image to that directory
func saveImage (image: UIImage, filename: String ){
print("Saving image with name \(filename)")
if let data = UIImagePNGRepresentation(image) {
let fullURL = getDocumentsDirectory().appendingPathComponent(filename)
try? data.write(to: fullURL)
}
}
Retrieving an image from the directory
func loadImageFromName(name: String) -> UIImage? {
print("Loading image with name \(name)")
let path = getDocumentsDirectory().appendingPathComponent(name).path
let image = UIImage(contentsOfFile: path)
if image == nil {
print("missing image at: \(path)")
}
return image
}
Sharing an image
func share(shareText shareText:String?,shareImage:UIImage?){
var objectsToShare = [AnyObject]()
if let shareTextObj = shareText{
objectsToShare.append(shareTextObj)
}
if let shareImageObj = shareImage{
objectsToShare.append(shareImageObj)
}
if shareText != nil || shareImage != nil{
let activityViewController = UIActivityViewController(activityItems: objectsToShare, applicationActivities: nil)
activityViewController.popoverPresentationController?.sourceView = self.view
present(activityViewController, animated: true, completion: nil)
}else{
print("There is nothing to share")
}
}
How to Use
let img: UIImage = UIImage() // Replace this with your image from your URL
saveImage(image: img, filename: "newImage.igo") //This is where you change your extension name
let newImage: UIImage = loadImageFromName(name: "newImage.igo") //Retrieve your image with the correct extension
share(shareText: "Image going to Instagram", shareImage: newImage) //Present Activity VC.
And as DFD pointed out, you can exclude certain items from the share VC to only allow what you need.

Answer 2

In my navigation controller, I have a UIBarButtonItem set to System item "Action". I then created the following IBAction code:
#IBAction func shareImage(_ sender: UIBarButtonItem) {
let context = CIContext()
let final = context.createCGImage(imgFinished, from: imgFinished.extent)
let shareImage = UIImage(cgImage: final!)
let vc = UIActivityViewController(activityItems: [shareImage], applicationActivities: [])
vc.excludedActivityTypes = [
UIActivityType.airDrop,
UIActivityType.assignToContact,
UIActivityType.addToReadingList,
//UIActivityType.copyToPasteboard,
//UIActivityType.mail,
//UIActivityType.message,
//UIActivityType.openInIBooks,
//UIActivityType.postToFacebook,
//UIActivityType.postToFlickr,
UIActivityType.postToTencentWeibo,
//UIActivityType.postToTwitter,
UIActivityType.postToVimeo,
UIActivityType.postToWeibo,
UIActivityType.print,
//UIActivityType.saveToCameraRoll
]
present(vc,
animated: true,
completion: nil)
vc.popoverPresentationController?.sourceView = self.view
vc.completionWithItemsHandler = {(activity, success, items, error) in
}
}
The excludedActivityTypes list is a complete/exhaustive list of available UIActivityTypes gleaned from code-complete or command-clicking on UIActivity type and going through the resulting struct. I uncomment those I wish to exclude - but leave them in for quick reference in the future. This will give you the popup you want.