How to use NSAttributedStrings in iOS with Swift? - ios

Question

I would like to have a label with an attributed string that changes dynamically at runtime. Something like this
Is there a better way to dynamically change the price value without hardcoding the attributed keys dictionaries and manually building the NSAttributedString?

Answer 1

The best way to approach Attributed Strings on iOS is by using the built-in Attributed Text editor in the interface builder and avoid uneccessary hardcoding NSAtrributedStringKeys in your source files.
You can later dynamically replace placehoderls at runtime by using this extension:
extension NSAttributedString {
func replacing(placeholder:String, with valueString:String) -> NSAttributedString {
if let range = self.string.range(of:placeholder) {
let nsRange = NSRange(range,in:valueString)
let mutableText = NSMutableAttributedString(attributedString: self)
mutableText.replaceCharacters(in: nsRange, with: valueString)
return mutableText as NSAttributedString
}
return self
}
}
Add a storyboard label with attributed text looking like this.
Then you simply update the value each time you need like this:
label.attributedText = initalAttributedString.replacing(placeholder: "<price>", with: newValue)
Make sure to save into initalAttributedString the original value.
You can better understand this approach by reading this article:
https://medium.com/mobile-appetite/text-attributes-on-ios-the-effortless-approach-ff086588173e

Answer 2

May not know, this is what you're looking for but will solve your problem.
You may use labels for each and update amount easily without touching attributed string.
Here is result:
Sample code, I've tried for this demo:
#IBOutlet weak var lblAmount: UILabel!
func pricelabel() -> Void {
var amount = 0
Timer.scheduledTimer(withTimeInterval: 0.3, repeats: true) { (timer) in
amount += 10
self.lblAmount.text = "\(amount)"
}.fire()
}