Swift: Display HTML data in a label or textView

Question

I have some HTML data, which contains headings, paragraphs , images and lists tags.

Is there a way to display this data in one UITextView or UILabel?

Answer 1

For Swift 5:

extension String {
    var htmlToAttributedString: NSAttributedString? {
        guard let data = data(using: .utf8) else { return nil }
        do {
            return try NSAttributedString(data: data, options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding:String.Encoding.utf8.rawValue], documentAttributes: nil)
        } catch {
            return nil
        }
    }
    var htmlToString: String {
        return htmlToAttributedString?.string ?? ""
    }
}

Then, whenever you want to put HTML text in a UITextView use:

textView.attributedText = htmlText.htmlToAttributedString

Answer 2

Here is a Swift 3 version:

private func getHtmlLabel(text: String) -> UILabel {
    let label = UILabel()
    label.numberOfLines = 0
    label.lineBreakMode = .byWordWrapping
    label.attributedString = stringFromHtml(string: text)
    return label
}

private func stringFromHtml(string: String) -> NSAttributedString? {
    do {
        let data = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
        if let d = data {
            let str = try NSAttributedString(data: d,
                                             options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
                                             documentAttributes: nil)
            return str
        }
    } catch {
    }
    return nil
}

I found issues with some of the other answers here and it took me a bit to get this right. I set the line break mode and number of lines so that the label sized appropriately when the HTML spanned multiple lines.

Answer 3

Add this extension to convert your html code to a regular string:

    extension String {

        var html2AttributedString: NSAttributedString? {
            guard
                let data = dataUsingEncoding(NSUTF8StringEncoding)
            else { return nil }
            do {
                return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil)
            } catch let error as NSError {
                print(error.localizedDescription)
                return  nil
            }
        }
        var html2String: String {
            return html2AttributedString?.string ?? ""
        }
}

And then you show your String inside an UITextView Or UILabel

textView.text = yourString.html2String or

label.text = yourString.html2String

Answer 4

For Swift 5, it also can load css.

extension String {
    public var convertHtmlToNSAttributedString: NSAttributedString? {
        guard let data = data(using: .utf8) else {
            return nil
        }
        do {
            return try NSAttributedString(data: data,options: [.documentType: NSAttributedString.DocumentType.html,.characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
        }
        catch {
            print(error.localizedDescription)
            return nil
        }
    }

    public func convertHtmlToAttributedStringWithCSS(font: UIFont? , csscolor: String , lineheight: Int, csstextalign: String) -> NSAttributedString? {
        guard let font = font else {
            return convertHtmlToNSAttributedString
        }
        let modifiedString = "<style>body{font-family: '\(font.fontName)'; font-size:\(font.pointSize)px; color: \(csscolor); line-height: \(lineheight)px; text-align: \(csstextalign); }</style>\(self)";
        guard let data = modifiedString.data(using: .utf8) else {
            return nil
        }
        do {
            return try NSAttributedString(data: data, options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
        }
        catch {
            print(error)
            return nil
        }
    }
}

After that, go to your string you want to convert to NSAttributedString and place it like the example below:

myUILabel.attributedText = "Swift is awesome!!!".convertHtmlToAttributedStringWithCSS(font: UIFont(name: "Arial", size: 16), csscolor: "black", lineheight: 5, csstextalign: "center")

Here’s what every parameter takes:

• font: Add your font as usually do in a UILabel/UITextView, using UIFont with the name of your custom font and the size.
• csscolor: Either add color in HEX format, like "#000000" or use the name of the color, like "black".
• lineheight: It’s the space between the lines when you have multiple lines in a UILabel/UITextView.
• csstextalign: It’s the alignment of the text, the value that you need to add is "left" or "right" or "center" or "justify"

Reference: https://johncodeos.com/how-to-display-html-in-uitextview-uilabel-with-custom-color-font-etc-in-ios-using-swift/

Answer 5

I had problems to change attributes of text after that, and I could see others asking why...

So best answer is to use extension with NSMutableAttributedString instead:

extension String {

 var htmlToAttributedString: NSMutableAttributedString? {
    guard let data = data(using: .utf8) else { return nil }
    do {
        return try NSMutableAttributedString(data: data,
                                      options: [.documentType: NSMutableAttributedString.DocumentType.html,
                                                .characterEncoding: String.Encoding.utf8.rawValue],
                                      documentAttributes: nil)
    } catch let error as NSError {
        print(error.localizedDescription)
        return  nil
    }
 }

}

And then you can use it this way:

if let labelTextFormatted = text.htmlToAttributedString {
                let textAttributes = [
                    NSAttributedStringKey.foregroundColor: UIColor.white,
                    NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 13)
                    ] as [NSAttributedStringKey: Any]
                labelTextFormatted.addAttributes(textAttributes, range: NSRange(location: 0, length: labelTextFormatted.length))
                self.contentText.attributedText = labelTextFormatted
            }

Answer 6

Swift 5

extension UIColor {
    var hexString: String {
        let components = cgColor.components
        let r: CGFloat = components?[0] ?? 0.0
        let g: CGFloat = components?[1] ?? 0.0
        let b: CGFloat = components?[2] ?? 0.0

        let hexString = String(format: "#%02lX%02lX%02lX", lroundf(Float(r * 255)), lroundf(Float(g * 255)),
                               lroundf(Float(b * 255)))

        return hexString
    }
}

extension String {
    func htmlAttributed(family: String?, size: CGFloat, color: UIColor) -> NSAttributedString? {
        do {
            let htmlCSSString = "<style>" +
                "html *" +
                "{" +
                "font-size: \(size)pt !important;" +
                "color: #\(color.hexString) !important;" +
                "font-family: \(family ?? "Helvetica"), Helvetica !important;" +
            "}</style> \(self)"

            guard let data = htmlCSSString.data(using: String.Encoding.utf8) else {
                return nil
            }

            return try NSAttributedString(data: data,
                                          options: [.documentType: NSAttributedString.DocumentType.html,
                                                    .characterEncoding: String.Encoding.utf8.rawValue],
                                          documentAttributes: nil)
        } catch {
            print("error: ", error)
            return nil
        }
    }
}

And final you can create UILabel:

func createHtmlLabel(with html: String) -> UILabel {
    let htmlMock = """
    <b>hello</b>, <i>world</i>
    """

    let descriprionLabel = UILabel()
    descriprionLabel.attributedText = htmlMock.htmlAttributed(family: "YourFontFamily", size: 15, color: .red)

    return descriprionLabel
}

Result:

See tutorial:

https://medium.com/@valv0/a-swift-extension-for-string-and-html-8cfb7477a510

Answer 7

Swift 3.0

var attrStr = try! NSAttributedString(
        data: "<b><i>text</i></b>".data(using: String.Encoding.unicode, allowLossyConversion: true)!,
        options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
        documentAttributes: nil)
label.attributedText = attrStr

Answer 8

I'm using this:

extension UILabel {
    func setHTML(html: String) {
        do {
            let attributedString: NSAttributedString = try NSAttributedString(data: html.data(using: .utf8)!, options: [NSDocumentTypeDocumentAttribute : NSHTMLTextDocumentType], documentAttributes: nil)
            self.attributedText = attributedString
        } catch {
            self.text = html
        }
    }
}

Answer 9

Swift 3

extension String {


var html2AttributedString: NSAttributedString? {
    guard
        let data = data(using: String.Encoding.utf8)
        else { return nil }
    do {
        return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:String.Encoding.utf8], documentAttributes: nil)
    } catch let error as NSError {
        print(error.localizedDescription)
        return  nil
    }
}
var html2String: String {
    return html2AttributedString?.string ?? ""
 }
}

Answer 10

Thx for the above answer here is Swift 4.2

extension String {

    var htmlToAttributedString: NSAttributedString? {
        guard
            let data = self.data(using: .utf8)
            else { return nil }
        do {
            return try NSAttributedString(data: data, options: [
                NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html,
                NSAttributedString.DocumentReadingOptionKey.characterEncoding: String.Encoding.utf8.rawValue
                ], documentAttributes: nil)
        } catch let error as NSError {
            print(error.localizedDescription)
            return  nil
        }
    }

    var htmlToString: String {
        return htmlToAttributedString?.string ?? ""
    }
}

Answer 11

Try this:

let label : UILable! = String.stringFromHTML("html String")

func stringFromHTML( string: String?) -> String
    {
        do{
            let str = try NSAttributedString(data:string!.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true
                )!, options:[NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: NSNumber(unsignedLong: NSUTF8StringEncoding)], documentAttributes: nil)
            return str.string
        } catch
        {
            print("html error\n",error)
        }
        return ""
    }

Hope its helpful.

Answer 12

Swift 5

extension String {
    func htmlAttributedString() -> NSAttributedString? {
        guard let data = self.data(using: String.Encoding.utf16, allowLossyConversion: false) else { return nil }
        guard let html = try? NSMutableAttributedString(
            data: data,
            options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
            documentAttributes: nil) else { return nil }
        return html
    }
}

Call:

myLabel.attributedText = "myString".htmlAttributedString()

Answer 13

extension UITextView {
    func setHTMLFromString(htmlText: String) {
        let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)

        let attrStr = try! NSAttributedString(
            data: modifiedFont.data(using: .utf8, allowLossyConversion: true)!,
            options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding:String.Encoding.utf8.rawValue],
            documentAttributes: nil)

        self.attributedText = attrStr
    }
}

Answer 14

Display images and text paragraphs is not possible in a UITextView or UILabel, to this, you must use a UIWebView.

Just add the item in the storyboard, link to your code, and call it to load the URL.

OBJ-C

NSString *fullURL = @"http://conecode.com";
NSURL *url = [NSURL URLWithString:fullURL];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[_viewWeb loadRequest:requestObj];

Swift

let url = NSURL (string: "http://www.sourcefreeze.com");
let requestObj = NSURLRequest(URL: url!);
viewWeb.loadRequest(requestObj);

Step by step tutorial. http://sourcefreeze.com/uiwebview-example-using-swift-in-ios/

Answer 15

If you want HTML, with images and a list, this isn't support by UILabel. However, I've found YYText does the trick.

Answer 16

IF YOU HAVE A STRING WITH HTML CODE INSIDE YOU CAN USE:

extension String {
var utfData: Data? {
        return self.data(using: .utf8)
    }

    var htmlAttributedString: NSAttributedString? {
        guard let data = self.utfData else {
            return nil
        }
        do {
            return try NSAttributedString(data: data,
                                          options: [
                                            .documentType: NSAttributedString.DocumentType.html,
                                            .characterEncoding: String.Encoding.utf8.rawValue
                ], documentAttributes: nil)
        } catch {
            print(error.localizedDescription)
            return nil
        }
    }

    var htmlString: String {
        return htmlAttributedString?.string ?? self 
    }
}

AND IN YOUR CODE YOU USE:

label.text = "something".htmlString