NSAttributedString not changing colour of certain text of NSTextview - swift

Question

I’m using NSAttributedString to change the text color of my NSTextview. When I want to change the color of a word, the color will not show. Here is my code for more detail
let main_string = “Hello World"
let string_to_color = “World"
let range = (main_string as NSString).range(of: string_to_color)
textView.textStorage?.addAttribute(NSAttributedString.Key.foregroundColor, value: NSColor.orange, range: range);
When I want the change the text Colour of another string,
let main_string = "Hello World"
let string_to_color = "World"
let range = (main_string as NSString).range(of: string_to_color)
textView.textStorage?.addAttribute(NSAttributedString.Key.foregroundColor, value: NSColor.orange, range: range)
let jhgfds = "Lorem Ipsum"
let tdftgdg = "ipsum"
let raresrgsdnge = (jhgfds as NSString).range(of: tdftgdg)
textView.textStorage?.addAttribute(NSAttributedString.Key.foregroundColor, value: NSColor.orange, range: range)
This is what happens
Can you please help me with this
Here is my full code…
import Cocoa
import WebKit
class ViewController: NSViewController, NSTextViewDelegate {
struct Keys {
static let noteBook = "noteTaking"
static let title = "appTitle"
}
#IBOutlet weak var livePreviewOn: NSButton!
var isPaused = true
var timer = Timer()
#IBOutlet var textView: NSTextView!
let defaults = UserDefaults.standard
#IBOutlet weak var webView: WKWebView!
#IBOutlet weak var scrollView: NSScrollView!
/// - Tag: setRepresentedObjectExample
override var representedObject: Any? {
didSet {
// Pass down the represented object to all of the child view controllers.
for child in children {
child.representedObject = representedObject
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
scrollView.magnification = 1.5
textView.isAutomaticQuoteSubstitutionEnabled = false
checkSavedText()
Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(self.updater), userInfo: nil, repeats: true)
}
#IBAction func pauseResume(sender: AnyObject) {
if isPaused{
timer = Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(self.update), userInfo: nil, repeats: true)
isPaused = false
} else {
timer.invalidate()
isPaused = true
}
}
#IBAction func saveBTN(_ sender: Any) {
saveNoteBookText()
}
func saveNoteBookText() {
defaults.set(textView.string, forKey: Keys.noteBook)
}
func checkSavedText() {
let name = defaults.value(forKey: Keys.noteBook) as? String ?? ""
textView.string = name
}
#objc func update() {
saveBTN(self)
webView.loadHTMLString(textView.string, baseURL: nil)
}
#objc func updater() {
saveBTN(self)
let main_string = "Hello World"
let string_to_color = "World"
let range = (textView.textStorage!.string as NSString).range(of: string_to_color)
textView.textStorage?.addAttribute(NSAttributedString.Key.foregroundColor, value: NSColor.orange, range: range)
}
}