NSFontAttributeName not applied to NSAttributedString

Question

I\'m currently using this extension provided by this answer to convert html to strings within a UITextView. Everything works perfectly but for some strange reas

Answer 1

Here i have updated to SWIFT 3

extension String {

    var utf8Data: Data? {
        return data(using: .utf8)
    }
}

extension Data {
    var attributedString: NSAttributedString? {
        do {
            return try NSAttributedString(data: self, options:[NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue,NSForegroundColorAttributeName:UIColor.white,NSFontAttributeName:UIFont.systemFont(ofSize: 15)], documentAttributes: nil)
        } catch let error as NSError {
            print(error.localizedDescription)
        }
        return nil
    }

    var attributedStringHtml: NSMutableAttributedString? {
        do {
         let   attrStr = try NSMutableAttributedString(data: self, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:String.Encoding.utf8.rawValue], documentAttributes: nil)
            attrStr.addAttributes([NSFontAttributeName: UIFont.systemFont(ofSize: 17.0),NSForegroundColorAttributeName:UIColor.white], range: NSRange(location: 0, length: attrStr.length))
            return attrStr
        } catch let error as NSError {
            print(error.localizedDescription)
        }
        return nil
    }
}

Usage

 DispatchQueue.global(qos: .background).async {
            let attribut = self.sampleText.utf8Data?.attributedStringHtml
            DispatchQueue.main.async {
                self.convertedTextLbl.attributedText = attribut
            }
        }

Answer 2

I'm not sure why (probably because of having a range) but it works if you first create an NSMutableAttributedString and then you add the UIFont attributes:

extension String {

    var html2AttributedString: NSMutableAttributedString? {
        guard
            let data = dataUsingEncoding(NSUTF8StringEncoding)
            else { return nil }
        do {
            let attrStr = try NSMutableAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil)
            attrStr.addAttributes([NSFontAttributeName: UIFont.systemFontOfSize(17.0)], range: NSRange(location: 0, length: attrStr.length))
            return attrStr
        } catch let error as NSError {
            print(error.localizedDescription)
            return  nil
        }
    }
    var html2String: String {
        return html2AttributedString?.string ?? ""
    }
}