Highlight words in between response dynamic data names

 "Work for Joy Bag is Started"
 "Work for Jack & Jill is Ended" 
 "Work for Uncle Sam is Started"

Need to highlight "Joy Bag", "Jack & Sam" and "Uncle Same" with bold and rest in regular font.

class StudentCell: UITableViewCell

var welcomeData: StudentListModel.Data?{
    didSet{
        setCellData()
    }
}

func setCellData() {
    
    if let titleValue = welcomeData?.title{
        let attributes = [[NSAttributedString.Key.foregroundColor:UIColor.red], [NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 17)]]
        nameValue.attributedText = titleValue.highlightWordsIn(highlightedWords: "Work for is Started", attributes: attributes)
    }
    
}

extension String {
    func highlightWordsIn(highlightedWords: String, attributes: [[NSAttributedString.Key: Any]]) -> NSMutableAttributedString {
        let range = (self as NSString).range(of: highlightedWords)
        let result = NSMutableAttributedString(string: self)
        for attribute in attributes {
            result.addAttributes(attribute, range: range)
        }
        return result
    }
}

From Given String "Work for Joy Bag is Started" In Between Work for - is Started or is Ended need to be Highlighted?

CodePudding user response：

The problem of your code is that your calling highlightWordsIn(highlightedWords: with "Welcome to A B" which will never match the words you want to highlight. You need some code that will extract the substring you want to highlight, something like this using a regex (only works if the string is like on your examples):

if let titleValue = welcomeData?.title {
    let substringToHighlight = titleValue.matches(regex: #"(?<=^Work for )\s* ([^,] ?)(?= is (Started|Ended)$)"#).first ?? ""
    let attributes = [[NSAttributedString.Key.foregroundColor:UIColor.red], [NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 17)]]
    nameValue.attributedText = titleValue.highlightWordsIn(highlightedWords: substringToHighlight, attributes: attributes)
}

Also added a method to the string extension:

extension String {
    func matches(regex: String) -> [String] {
        guard let regex = try? NSRegularExpression(pattern: regex, options: []) else { return [] }
        let matches  = regex.matches(in: self, options: [], range: NSMakeRange(0, self.count))
        return matches.map { match in
            return String(self[Range(match.range, in: self)!])
        }
    }
}

Another simpler regex to match between "for" and "is":

(?<=for )\s* ([^,] ?)(?= is)