Swift IOS Custom Action in Number Detection - ios

Question

In our App, we have an outbound VOIP phone dialer.
I would like to detect numbers within a string and add a custom action so that instead of the default behaviour to open the native dialer, it will go to our own dialler within the App and pre-populate the selected number.
My first thoughts were to get the body of the message into a string array of words and check each word to see if it is a number and then create an attributed string. But I'm struggling to understand how I can get an attributed string back into a string and what I would even specify to open the said screen with the number pre-populated.
I am aware of NSDataDetector which can list the numbers found in the string but I am stuck with how to replace those particular parts with a clickable action and return it back as a string.
If anyone has had similar experiences with this then any help would be much appreciated?
NOTE : The body of this message is being show in a UILabel control.
Update
this is what I had so far...
func AddNumberLink() -> String {
let body = self
let wordsInBody = body.components(separatedBy: .whitespaces)
for i in 0..<wordsInBody.count {
var word = wordsInBody[i]
if word.isTelephoneNumeric {
let attributedString = NSMutableAttributedString(string:word)
attributedString.addAttribute(NSAttributedStringKey.link, value:"https://www.google.com",range: NSRange(location: 0, length: word.count))
attributedString.addAttribute(NSAttributedStringKey.foregroundColor,value: UIColor.red, range: NSRange(location:0, length: word.count))
word = attributedString.string
}
}
return body
}

Answer 1

NSDataDetector gives you the ranges of the numbers. Now, create a (mutable) attributed string and for each range, add a link to the corresponding number URL (NSAttributedString.Key.link: urlString).
Then, display the text in a UITextView and add a delegate.
In the delegate, implement func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool
In this function, you can decide what action is appropriate.

Answer 2

Thank you all for your suggestions it has made me approach the problem in a different manner to my code above.
Like #Lutz and #Larme suggested above, by overriding the default behaviour when the UITextView is tapped I can gather the number via the UITextViewDelegate.
So the complete solution is :
Add number detector attribute to UITextView
Implement UITextViewDelegate func textView(_ textView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool
Add custom logic to handle the tap accordingly.