获取编辑的UITextView单词

Question

I'm trying to get the word that's being typed from a UITextView . I have the following code placed in textViewDidChange(_:) that I found from another answer on here, but it doesn't work for emojis:

func editedWord() -> String {
    let cursorPosition = selectedRange.location
    let separationCharacters = CharacterSet(charactersIn: " ")

    // Count how many actual characters there are before the cursor.
    // Emojis/special characters can each increase selectedRange.location
    // by 2 instead of 1

    var unitCount = 0
    var characters = 0
    while unitCount < cursorPosition {
        let char = text.index(text.startIndex, offsetBy: characters)
        let int = text.rangeOfComposedCharacterSequence(at: char) // Crashes here when there's an emoji.
        unitCount = text.distance(from: text.startIndex, to: int.upperBound)
        characters += 1
    }

    let beginRange = Range(uncheckedBounds: (lower: text.index(text.startIndex, offsetBy: 0), upper: text.index(text.startIndex, offsetBy: characters)))
    let endRange = Range(uncheckedBounds: (lower: text.index(text.startIndex, offsetBy: characters), upper: text.index(text.startIndex, offsetBy: text.characters.count)))


    let beginPhrase = text.substring(with: beginRange)
    let endPhrase = text.substring(with: endRange)

    let beginWords = beginPhrase.components(separatedBy: separationCharacters)
    let endWords = endPhrase.components(separatedBy: separationCharacters)

    return beginWords.last! + endWords.first!
}

I've indicated the position that it crashes at in the while loop, and the crash says that "The index X is invalid". How can I fix this?

Answer 1

You should fetch the last word from the string. Here is the code to fetch it:

__block NSString *lastWord = nil;

[someNSStringHere enumerateSubstringsInRange:NSMakeRange(0, [someNSStringHere length]) options:NSStringEnumerationByWords | NSStringEnumerationReverse usingBlock:^(NSString *substring, NSRange subrange, NSRange enclosingRange, BOOL *stop) {

    lastWord = substring;
    *stop = YES;
}];

Hope this helps!