Generate dynamic text attribute by pattern

Question

I have a string like this

var str = "This is &my& apple, I bought it %yesterday%"

Everything inside & & mark will be italics, inside % % mark will turn into bold style and set this data to a UILabel. The final output will be:

This is my apple, I bought it yesterday

Edited: I am using %(.*?)% as a regex pattern to extract the substring

Is there any way to solve this issue? Please help

Thanks in advance.

Leo Dabus · Accepted Answer · 2017-11-12T15:01:05.467

You can use replacingOccurrences of regex to put the matches between bold and italic html tags and then use NSAttributedString to convert your html string to attributed string.

let str = "This is &my& apple, I bought it %yesterday%"

let html = str
    .replacingOccurrences(of: "(&.*?&)", with: "<b>"+"$1"+"</b>", options: .regularExpression)
    .replacingOccurrences(of: "&(.*?)&", with: "$1", options: .regularExpression)
    .replacingOccurrences(of: "(%.*?%)", with: "<i>"+"$1"+"</i>", options: .regularExpression)
    .replacingOccurrences(of: "%(.*?)%", with: "$1", options: .regularExpression)

Converting your html to attributed string

let label = UILabel(frame: CGRect(origin: .zero, size: CGSize(width: 300, height: 50)))
label.font = UIFont.systemFont(ofSize: 14)
do {
    label.attributedText = try NSAttributedString(data: Data(html.utf8), options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
} catch {
    print("error:", error)
}

thanks for your help. It's working but showing me a warning about "+[CATransaction synchronize] called within transaction", do you know what is it and how to silent it — Shin622, Nov 12 '17 at 15:28
@user3783161 I don't think thats related to the code above. Try isolating your issue and if you post a sample project I can take a look at it. — Leo Dabus, Nov 12 '17 at 15:30

Generate dynamic text attribute by pattern

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