Swift UIText View replaceCharacters Out of bounds - swift

Question

I try to replace link to image and show on TextView
This my code
class ViewController: UIViewController {
let textView: UITextView = {
let view = UITextView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(textView)
textView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
textView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
textView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
textView.topAnchor.constraint(equalTo: view.topAnchor, constant: 50).isActive = true
let input = "New iPhone \nhttp://cdn2.gsmarena.com/vv/bigpic/apple-iphone-6s1.jpg \nTest Test Test"
imageText(text: input)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func imageText(text:String) {
let attributedString = NSMutableAttributedString(string: text)
let detector = try? NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
let matches = detector?.matches(in: text, options: .reportCompletion, range:NSRange(location: 0, length: text.count))
for match in matches! {
if match.url?.absoluteString.suffix(3) == "jpg" {
let textAttachment = NSTextAttachment()
let data = NSData(contentsOf: (match.url!))
if data != nil{
let image = UIImage(data: data! as Data)
textAttachment.image = image
let attributedStringWithImage = NSAttributedString(attachment: textAttachment)
attributedString.replaceCharacters(in: (match.range), with: attributedStringWithImage)
}
}
}
textView.attributedText = attributedString
}
}
It works:
App Screen Shot
But if I add a second link, then it crashes.
let input = "New iPhone \nhttp://cdn2.gsmarena.com/vv/bigpic/apple-iphone-6s1.jpg \nTest Test Test \nhttp://cdn2.gsmarena.com/vv/bigpic/apple-iphone-6s1.jpg \nTest Test Test"
console
reason: 'NSMutableRLEArray replaceObjectsInRange:withObject:length:: Out of bounds'
I find the crash point is this line
attributedString.replaceCharacters(in: (match.range), with: attributedStringWithImage)
How to fix this problem?

Answer 1

The thing is: you are mutating attributedString in this line
attributedString.replaceCharacters(in: (match.range), with: attributedStringWithImage)
So, in the following iteration of the for loop, the range that you are trying to replace doesn't exist anymore.