Assigns attributed text to the label by iterating through an array of strings with associated FontTypes.

UILabel+AttributedString.swift

/// Used to identify the intended format of a string when using the `attributedTextFromArray:` func of a UILabel extension.
enum FontType {
    case system, bold, italic, underlined
}

extension UILabel {
    /**
    Assigns attributed text to the label by iterating through an array of strings with associated FontTypes.

    Example use:

         thoughtBubbleLabel.attributedTextFromArray([
             ( "\"What a handy extension,\" ", .Italic ),
             ( "he thought to himself. ", .System ),
             ( "\n", .System ),
             ( "Indeed. ", .Bold ),
             ( "It was.", .Underlined ),
         ])

    When used with the String extension:

         thoughtBubbleLabel.attributedTextFromArray([
              "\"What a handy extension,\" ".Italic,
              "he thought to himself. ".System,
              "\n".System,
              "Indeed. ".Bold,
              "It was.".Underlined
         ])

    **NOTE:** This assumes that the desired label font size is consistant throughout and has already been set.

    - parameter components: A tuple array of strings with associated FontTypes.
    */
    func attributedTextFromArray(_ components: [(String, FontType)]) {
        let size = font.pointSize
        let attrString = NSMutableAttributedString()

        for component in components {
            let (text, attr) = component
            let font: UIFont

            switch attr {
            case .system:
                font = UIFont.systemFont(ofSize: size)
            case .bold:
                font = UIFont.boldSystemFont(ofSize: size)
            case .italic:
                font = UIFont.italicSystemFont(ofSize: size)
            case .underlined:
                attrString.append(NSAttributedString(string: text, attributes: [NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue]))
                continue
            }
            attrString.append(NSAttributedString(string: text, attributes: [NSFontAttributeName: font]))
        }
        attributedText = attrString
    }
}

// swiftlint:disable variable_name
extension String {
    /// Convenient way to instantly convert a string to a `(String, FontType)` object for use with the `attributedTextFromArray:` func of a UILabel extension.
    var Bold: (String, FontType) {
        return ( self, .bold )
    }

    /// Convenient way to instantly convert a string to a `(String, FontType)` object for use with the `attributedTextFromArray:` func of a UILabel extension.
    var Italic: (String, FontType) {
        return ( self, .italic )
    }

    /// Convenient way to instantly convert a string to a `(String, FontType)` object for use with the `attributedTextFromArray:` func of a UILabel extension.
    var Underlined: (String, FontType) {
        return ( self, .underlined )
    }

    /// Convenient way to instantly convert a string to a `(String, FontType)` object for use with the `attributedTextFromArray:` func of a UILabel extension.
    var System: (String, FontType) {
        return ( self, .system )
    }
}