NSAttributeString battling css scripting already in a string

Okay I'm having an issue with NSAttributeString. I'm getting different html/css strings that occupy "busDescriptio" depending on what business you choose from a website database. I'm able to customize the string as I see fit as NSAttributeString but unfortunately on some cases the string already has css scripting in it which overrides my style that I insert into the string. Is it possible to override the scripting that is within my string? If so, how would I be able to do this? ***If I cant override the script can I just extract a certain tag from my string or replace it? Oh here is what my string looks like. As you see their is a style that is being poppulated within the string aka(busDescriptio). I'm not able to change that with regular scripting using NSAttributeString.

 /* This is a random description my busDescriptio pulls in which changes everytime someone selects a different business*/<p><span style="color:rgb(0, 0, 0); font-family:verdana,arial,tahoma; font-size:12px">Baxter Eye Care has been serving The Woodlands with quality eye care and personal friendly service since 1981. &nbsp;Dr. Baxter, Dr. Daniels and Dr. Shosa are dedicated to your eye health and vision needs.</span></p>

This is the code I'm using to do this

extension String {
    var html2String:String {
        return NSAttributedString(data: dataUsingEncoding(NSUTF8StringEncoding)!, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil, error: nil)!.string
    }
    var html2NSAttributedString:NSAttributedString {
        return NSAttributedString(data: dataUsingEncoding(NSUTF8StringEncoding)!, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil, error: nil)!
    }
}
extension NSData{
    var htmlString:String {
        return  NSAttributedString(data: self, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil, error: nil)!.string
    }
}
let result = html2String("\(busDescriptio)") // Business Description HTML

            let yourAttributedText = "<style type=\"text/css\">#busDescriptio{color:white;align-content:left;}#green{color:#0F0}#blue{color: #00F; font-weight: Bold; font-size: 32}</style><span id=\"busDescriptio\" >\(result),</span><span id=\"green\" > Green </span><span id=\"blue\">and Blue</span>".html2NSAttributedString

            // Create UITextView
            var textView = UITextView(frame: CGRectMake(0, 95.0, screenWidth-10, 300.0))
            textView.attributedText = yourAttributedText
            textView.backgroundColor = UIColor.clearColor()
            textView.font = UIFont.preferredFontForTextStyle(UIFontTextStyleBody)

            border.addSubview(textView)
func html2String(html:String) -> String {
        return NSAttributedString(data: html.dataUsingEncoding(NSUTF8StringEncoding)!, options:[NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil, error: nil)!.string
    }

Solution

I think you're stuck thinking about HTML. Once you have created an NSAttributedString or, more accurately, an NSMutableAttributedString from the HTML, you can just apply your own attributes. At that point, the HTML is no longer relevant. You certainly shouldn't try to achieve formatting by manipulating the HTML before converting it into an attributed string.

You don't say what "style" or attributes you want to change, so it's hard to give you an example, but just set or remove whatever attributes you want. You have the power to completely override whatever styling was introduced by the CSS in the HTML.

For example, do [someMutableAttributedString addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(0, someMutableAttributedString.length)] to change the color to blue.

Here's some Objective-C code which works for me on OS X:

NSString* html = @"<style type=\"text/css\">#busDescriptio{color:white;align-content:left;}#green{color:#0F0}#blue{color: #00F; font-weight: Bold; font-size: 32}</style><span id=\"busDescriptio\" ><p><span style=\"color:rgb(0, 0, 0); font-family:verdana,arial,tahoma; font-size:12px\">Baxter Eye Care has been serving The Woodlands with quality eye care and personal friendly service since 1981. &nbsp;Dr. Baxter, Dr. Daniels and Dr. Shosa are dedicated to your eye health and vision needs.</span></p>,</span><span id=\"green\" > Green </span><span id=\"blue\">and Blue</span>";
NSData* data = [html dataUsingEncoding:NSUTF8StringEncoding];

NSMutableAttributedString* str = [[NSMutableAttributedString alloc] initWithData:data
                                                                         options:@{ NSCharacterEncodingDocumentOption: @(NSUTF8StringEncoding),
                                                                                    NSDocumentTypeDocumentOption: NSHTMLTextDocumentType }
                                                              documentAttributes:NULL
                                                                           error:NULL];
[str addAttribute:NSForegroundColorAttributeName value:[NSColor redColor] range:NSMakeRange(0, str.length)];
self.label.attributedStringValue = str;

I don't work in Swift, but here's a pass at a simple translation:

let html = "<style type=\"text/css\">#busDescriptio{color:white;align-content:left;}#green{color:#0F0}#blue{color: #00F; font-weight: Bold; font-size: 32}</style><span id=\"busDescriptio\" ><p><span style=\"color:rgb(0, 0, 0); font-family:verdana,arial,tahoma; font-size:12px\">Baxter Eye Care has been serving The Woodlands with quality eye care and personal friendly service since 1981. &nbsp;Dr. Baxter, Dr. Daniels and Dr. Shosa are dedicated to your eye health and vision needs.</span></p>,</span><span id=\"green\" > Green </span><span id=\"blue\">and Blue</span>"
let data = html.dataUsingEncoding(NSUTF8StringEncoding)!

var str = NSMutableAttributedString(data:data,
                                    options:[ NSCharacterEncodingDocumentOption: NSUTF8StringEncoding,
                                              NSDocumentTypeDocumentOption: NSHTMLTextDocumentType ],
                                    documentAttributes:nil,
                                    error:nil)
str.addAttribute(NSForegroundColorAttributeName, value:NSColor.redColor(), range:NSMakeRange(0, str.length))
self.label.attributedStringValue = str;

So, the code starts with HTML code in a string. It creates an NSMutableAttributedString from that. Then it changes the foreground color, effectively replacing the color resulting from the HTML. Finally, it sets the attributed string as the content of an NSTextField label. For iOS, you could use a UILabel or UITextView or whatever.

In the code you put in your question, there are some things that are troublesome. It's not clear what busDescription is. Is it a string containing HTML code?

Is there a reason that you're interpolating it into a string to pass it to html2String()? That is, why this:

let result = html2String("\(busDescriptio)")

and not this:

let result = html2String(busDescriptio)

It seems that html2String() interprets HTML into an attributed string and then just extracts the plain text from that. Why are you doing that?

You are then interpolating that plain text into another block of HTML code. Again, why are you doing that? If you want to apply colors, fonts, etc. to the plain text string, just build an attributed string directly from that plain text string — no HTML involved — and apply the desired attributes.

Or, start from the original busDescriptio, make a mutable attributed string from that HTML code, and apply whatever attributes you like to that.

For example, here's another example:

NSString* busDescriptio = @"<p><span style=\"color:rgb(0, 0, 0); font-family:verdana,arial,tahoma; font-size:12px\">Baxter Eye Care has been serving The Woodlands with quality eye care and personal friendly service since 1981. &nbsp;Dr. Baxter, Dr. Daniels and Dr. Shosa are dedicated to your eye health and vision needs.</span></p>";
NSData* data = [busDescriptio dataUsingEncoding:NSUTF8StringEncoding];
NSMutableAttributedString* foo = [[NSMutableAttributedString alloc] initWithData:data
                                                                         options:@{ NSCharacterEncodingDocumentOption: @(NSUTF8StringEncoding),
                                                                                    NSDocumentTypeDocumentOption: NSHTMLTextDocumentType }
                                                              documentAttributes:NULL
                                                                           error:NULL];
[str addAttribute:NSFontAttributeName value:[NSFont fontWithName:@"Verdana" size:12] range:NSMakeRange(0, str.length)];

Basically, although your initial input is HTML code, you build a mutable attributed string from that and then don't work in HTML from that point on. Just apply and/or remove attributes from the attributed string, as desired. You can also build separate attributed strings, like your green or blue text in your example, and append those to the mutable one.