Calculate range of string from word to end of string in swift

Question

I have an NSMutatableString:

var string: String = "Due in %@ (%@) $%@.\nOverdue! Please pay now %@"
attributedText = NSMutableAttributedString(string: string, attributes: attributes)

How to calculate both the length and starting index from the word Overdue in swift?

so far I have tried:

let startIndex = attributedText.string.rangeOfString("Overdue")
let range = startIndex..<attributedText.string.finishIndex

// Access the substring.
let substring = value[range]
print(substring)

But it doesn't work.

Stoffel

Answer 1

You should generate the resulting string first:

let string = String(format: "Due in %@ (%@) $%@.\nOverdue! Please pay now %@", "some date", "something", "15", "some date")

Then use .disTanceTo to get the distance between indices;

if let range = string.rangeOfString("Overdue") {
  let start = string.startIndex.distanceTo(range.startIndex)
  let length = range.startIndex.distanceTo(string.endIndex)

  let wordToEndRange = NSRange(location: start, length: length) 
  // This is the range you need

  attributedText.addAttribute(NSForegroundColorAttributeName, 
     value: UIColor.blueColor(), range: wordToEndRange)
}

---

Please do note that NSRange does not work correctly if the string contains Emojis or other Unicode characters so that the above solution may not work properly for that case.

Please look at the following SO answers for a better solution which cover that case as well:

• https://mcmap.net/q/23791/-nsrange-from-swift-range
• https://mcmap.net/q/23817/-swift-extract-regex-matches

Afoul

Genius. Solved 2 of my problems by adding the color. Thank you so much @ozgur! Wish I could double up vote. – Stoffel

This conversion of string indices to NSRange does not work correctly if the string contains Emojis or other Unicode characters > U+FFFF. Compare #27881150 and https://mcmap.net/q/23791/-nsrange-from-swift-range for similar issues. – You can try it with let string = "😀😀😀 Bla bla Overdue! bla bla" – Sunless

Answer 2

Look at this,

                let nsString = element.text as NSString
                let range = nsString.range(of: word, options: .widthInsensitive)
                let att: [NSAttributedString.Key: Any] = [.foregroundColor: UIColor.systemBlue]
                attText.addAttributes(att, range: NSRange(location: range.location, length: range.length))

Flinch

Please add some explanation. Why do you think your proposed solution might help the OP. – Nonobedience

Answer 3

Base of the Mahadev Prabhu's answer:

extension String {
    func getRange(of word: String)-> NSRange {
        return (self as NSString).range(of: word, options: .widthInsensitive)
    }
}

Shovelboard