Get color changed words of attributed string - ios

Question

I have a UITextView that allows to select words of the text by tapping it. If it is tapped the word is highlighted in color by changing the NSForegroundColor attribute.
Tapping it again deselects it by changing the color back to the textcolor.
Now I would need to know all selected words in the UITextView.
The first idea was to remove everything that is a special character and split the text at space. Then check if the color attribute is equals to the selected/highlighted color of each seperate word.
But attributed string doesn't allow to split at a character or remove components. Neither does NSAttributedString.
Second idea was to save the ranges of the highlighted parts in an array and iterate over it to get the highlighted parts. But this seems a bit too complicated for me, especially as I need the correct order of the words as they appear which is not guaranteed with an array, add/remove on each tap
(For example let's say the text is: "This is a test"
Tap this -> index 0
Tap test -> index 1
Tap this -> test becomes index 0
Tap this -> this becomes index 1
then the order is not good anymore.
I already figured out how to get the color of an attributed string. That's not the problem.
How can I iterate over the attributed string and figure out the words that have changed color or what is the best way to solve this problem?
Thank you!
Greetings

Answer 1

You can iterate over the attributed string looking for the color attribute.
The follow code demonstrates how:
// This generates a test attributed string.
// You actually want the attributedText property of your text view
let str = NSMutableAttributedString(string: "This is a test of the following code")
str.addAttributes([NSForegroundColorAttributeName:UIColor.red], range: NSMakeRange(0, 4))
str.addAttributes([NSForegroundColorAttributeName:UIColor.red], range: NSMakeRange(8, 1))
str.addAttributes([NSForegroundColorAttributeName:UIColor.red], range: NSMakeRange(15, 2))
print(str)
The above prints:
This{
NSColor = "UIExtendedSRGBColorSpace 1 0 0 1";
} is {
}a{
NSColor = "UIExtendedSRGBColorSpace 1 0 0 1";
} test {
}of{
NSColor = "UIExtendedSRGBColorSpace 1 0 0 1";
} the following code{
}
This code processes the attributed string. Any range of text formatted with a foreground color will be put into the words array.
var words = [String]()
str.enumerateAttribute(NSForegroundColorAttributeName, in: NSMakeRange(0, str.length), options: []) { (value, range, stop) in
if value != nil {
let word = str.attributedSubstring(from: range).string
words.append(word)
}
}
print(words)
This prints:
["This", "a", "of"]

Answer 2

I can suggest you to create some kind of storage for selected ranges, then based on this range you can customize look of this words, not the other way. It will allow you to access selected words every time without checking attributes of whole text.

Answer 3

While I agree with Piotr that you should store the Ranges, to answer your question:
attributedString.enumerateAttributes(in: NSMakeRange(0, attributedString.length), options: []) { attributes, range, _ in
if let color = attributes[NSForegroundColorAttributeName] as? UIColor,
color == YOUR_HIGHLIGHT_COLOR {
let nString = attributedString.string as NSString
let word = nString.substring(with: range)
// Do what you want with the word
}
}