How do I make an attributed string using Swift?

Question

I am trying to make a simple Coffee Calculator. I need to display the amount of coffee in grams. The \"g\" symbol for grams needs to be attached to my UILabel that I am usin

Answer 1

Xcode 6 version:

let attriString = NSAttributedString(string:"attriString", attributes:
[NSForegroundColorAttributeName: UIColor.lightGrayColor(), 
            NSFontAttributeName: AttriFont])

Xcode 9.3 version:

let attriString = NSAttributedString(string:"attriString", attributes:
[NSAttributedStringKey.foregroundColor: UIColor.lightGray, 
            NSAttributedStringKey.font: AttriFont])

Xcode 10, iOS 12, Swift 4:

let attriString = NSAttributedString(string:"attriString", attributes:
[NSAttributedString.Key.foregroundColor: UIColor.lightGray, 
            NSAttributedString.Key.font: AttriFont])

Answer 2

extension UILabel{
    func setSubTextColor(pSubString : String, pColor : UIColor){    
        let attributedString: NSMutableAttributedString = self.attributedText != nil ? NSMutableAttributedString(attributedString: self.attributedText!) : NSMutableAttributedString(string: self.text!);

        let range = attributedString.mutableString.range(of: pSubString, options:NSString.CompareOptions.caseInsensitive)
        if range.location != NSNotFound {
            attributedString.addAttribute(NSForegroundColorAttributeName, value: pColor, range: range);
        }
        self.attributedText = attributedString
    }
}

Answer 3

Swift 5

    let attrStri = NSMutableAttributedString.init(string:"This is red")
    let nsRange = NSString(string: "This is red").range(of: "red", options: String.CompareOptions.caseInsensitive)
    attrStri.addAttributes([NSAttributedString.Key.foregroundColor : UIColor.red, NSAttributedString.Key.font: UIFont.init(name: "PTSans-Regular", size: 15.0) as Any], range: nsRange)
    self.label.attributedText = attrStri

Answer 4

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 5

Works well in beta 6

let attrString = NSAttributedString(
    string: "title-title-title",
    attributes: NSDictionary(
       object: NSFont(name: "Arial", size: 12.0), 
       forKey: NSFontAttributeName))

Answer 6

I would highly recommend using a library for attributed strings. It makes it much easier when you want, for example, one string with four different colors and four different fonts. Here is my favorite. It is called SwiftyAttributes

If you wanted to make a string with four different colors and different fonts using SwiftyAttributes:

let magenta = "Hello ".withAttributes([
    .textColor(.magenta),
    .font(.systemFont(ofSize: 15.0))
    ])
let cyan = "Sir ".withAttributes([
    .textColor(.cyan),
    .font(.boldSystemFont(ofSize: 15.0))
    ])
let green = "Lancelot".withAttributes([
    .textColor(.green),
    .font(.italicSystemFont(ofSize: 15.0))

    ])
let blue = "!".withAttributes([
    .textColor(.blue),
    .font(.preferredFont(forTextStyle: UIFontTextStyle.headline))

    ])
let finalString = magenta + cyan + green + blue

finalString would show as