NSAttributedString to HTML string without CSS

I am trying to convert HTML to NSAttributedString format and back. Converting from HTML works fine, however converting back to HTML gives me a format I cannot send to our backend:

<!DOCTYPE html PUBLIC -//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv=Content-Style-Type" content="text/css">
<title></title>
<meta name="Generator" content="Cocoa HTML Writer">
<style type="text/css">
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; line-height: 15.0px; font: 16.0px 'Times New Roman'; color: #000000; -webkit-text-stroke: #000000}
span.s1 {font-family: 'Times New Roman'; font-weight: normal; font-style: normal; font-size: 16.00pt; font-kerning: none}
span.s2 {font-family: 'TimesNewRomanPS-BoldMT'; font-weight: bold; font-style: normal; font-size: 16.00pt; font-kerning: none}
span.s3 {font-family: 'TimesNewRomanPS-ItalicMT'; font-weight: normal; font-style: italic; font-size: 16.00pt; font-kerning: none}
span.s4 {font-family: 'TimesNewRomanPS-BoldItalicMT'; font-weight: bold; font-style: italic; font-size: 16.00pt; font-kerning: none}
</style>
</head>
<body>
<p class="p1"><span class="s1">vanlig text </span><span class="s2">bold</span><span class="s1"> </span><span class="s3">italic</span><span class="s1"> </span><span class="s4">bold_italic asd</span></p>
</body>
</html>

The string/format I need to send my server cannot have css and needs to be something more like this: (without CSS)

<html>
<body>
<p>vanlig text <b>bold</b> <i>italic</i><b><i>bold_italic asd</i></b>
</p>
</body>
</html>

I've tried this solution without success: NSAttribute string to HTML I keeps the format with css.

My code so far:

extension NSAttributedString
{
    var htmlString : String
    {
        let documentAttributes = [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType]
        if let htmlData = try? self.dataFromRange(NSMakeRange(0, self.length), documentAttributes:documentAttributes),
           let htmlString = String(data:htmlData, encoding:NSUTF8StringEncoding) {
            return htmlString
        }
        return ""
    }

    func attributedStringWithNoTrailingNewLines() -> NSMutableAttributedString
    {
        let mutableAttributedString = NSMutableAttributedString(attributedString: self)
        let nsString = string as NSString
        let lastWhitespaceOrNewlineRange = nsString.rangeOfCharacterFromSet(NSCharacterSet.whitespaceAndNewlineCharacterSet(), options: .BackwardsSearch)
        if lastWhitespaceOrNewlineRange.length != 0 && NSMaxRange(lastWhitespaceOrNewlineRange) == self.length
        {
            mutableAttributedString.replaceCharactersInRange(lastWhitespaceOrNewlineRange, withString: "")
        }
        return mutableAttributedString
    }
}

extension String
{
    var attributedString : NSAttributedString?
    {
        if let data = self.dataUsingEncoding(NSUTF8StringEncoding) {
            let options = [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType]
            let attrStr = try? NSAttributedString(data: data, options: options, documentAttributes: nil)
            return attrStr
        }
        return nil
    }
}

Solution

I do not have the exact code I used to solve it, but I solved it by iterating the nsfontattributes and manually adding the supported html tags. Something like this in a NSAttributedString extension:

enumerateAttribute(NSFontAttributeName, inRange: NSMakeRange(0, length), options: NSAttributedStringEnumerationOptions(rawValue: 0)) { (value, range, stop) in
    if let font = value as? UIFont {
        var stringInRange = string.substringInRange(range)
        if font.isBold {
            stringInRange = "<b>\(stringInRange)</b>"
        }
        if font.isItalic {
            stringInRange = "<i>\(stringInRange)</i>"
        }
        // ...
    }
}