UIMenuController doesn't update menu for first time - ios

Question

I have UITextView on which I want to add highlight as custom menu item. I have registered to following notification UIMenuControllerWillShowMenuNotification.
The method for the notification is something like this:
if textIsHighlighted {
let highlightMenuItem = UIMenuItem(title: "Highlight", action: Selector("highlightText"))
UIMenuController.sharedMenuController().menuItems = [highlightMenuItem]
}
else {
let highlightMenuItem = UIMenuItem(title: "Dehighlight", action: Selector("highlightText"))
UIMenuController.sharedMenuController().menuItems = [highlightMenuItem]
}
Although the first time the menucontroller fails to update even though it executes the part of code. It shows the last value. Where should I write this part of code as I feel that during willShow menuController it's already created and thus fails to update.

Answer 1

Hopefully you've solved this by now, but I've just figured this one out myself:
Other answers have said you can update the menu items by adding it when the UIMenuControllerWillShowMenuNotification is called, but this wasn't working for me (iOS 9, Swift 2).
Instead I implemented the UITextView delegate method: textViewDidChangeSelection and set the relevant menu items there:
func textViewDidChangeSelection(textView: UITextView) {
if self.currentSelectionIsInHighlightedRange() {
self.setUpUnhighlightMenuItem()
} else {
self.setUpHighlightMenuItem()
}
}
private func currentSelectionIsInHighlightedRange() -> Bool {
let allHighlightedRanges = self.document.highlightedRanges()
let selectedTextRange = self.documentView.textView.selectedRange
for range in allHighlightedRanges {
let intersectionRange = NSIntersectionRange(range, selectedTextRange)
if intersectionRange.length > 0 {
return true
}
}
return false
}