NSAttributedString from HTML with Hyperlinks - html

I am attempting to render a large HTML string, that contains hyperlinks, into a UITextView using NSAttributedString. Everything is working fine except the hyperlinks, they don't actually open the link.
For an example, here is a dummy version of my html string:
let htmlString = "<html><p>If you would like to contact someone, you can email
them at <a class=rvts10 href=\"mailto:some#one.com\">some#one.com</a></p></html>"
I have a function called convertHTML() that converts strings to NSAttributedString with html document type options, that I use to assign to the UITextView's attributed text:
textView.attributedText = htmlString.convertHTML()
The TextField is selectable but not editable. When the page is loaded, you can see the hyperlink styling (blue text) and everything, but you can't tap on the link and open the mail app.
I assume this I need to change "mailto:..." to something else that iOS will recognize, but I just have no idea what needs to be done to allow this link to be linkable.
This is my html method:
func convertHtml() -> NSAttributedString{
guard let data = data(using: .utf8) else { return NSAttributedString() }
do{
return try NSAttributedString(data: data, options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
}catch{
return NSAttributedString()
}
}


I think you have error with your convertHTML() Method check this
let htmlString = "<html><p>If you would like to contact someone, you can email them at <a class=rvts10 href=\"mailto:some#one.com\">some#one.com</a></p></html>"
// you have to convert string to data
let data = Data(htmlString.utf8)
// then convert data to NSAttributedString with NSAttributedString.DocumentType.htm
if let attributedString = try? NSAttributedString(data: data, options: [.documentType: NSAttributedString.DocumentType.html], documentAttributes: nil) {
self.textView.attributedText = attributedString
}


I use this extension :
import Foundation
extension NSAttributedString {
convenience init(htmlString html: String) throws {
try self.init(data: Data(html.utf8), options: [
.documentType: NSAttributedString.DocumentType.html,
.characterEncoding: String.Encoding.utf8.rawValue
], documentAttributes: nil)
}
}
After implementing you can use it like this:
contentTextField.attributedText = try? NSAttributedString(htmlString: aHTMLString)

Related

The file couldn’t be opened because the text encoding of the contents couldn’t be determined

import UIKit
import SwiftSoup
class ViewController: UIViewController {
#IBOutlet weak var Ingrediants: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
let content = try! String(contentsOf: URL(string: "https://google.com")!)
let doc: Document = try! SwiftSoup.parse(content)
let tables = try! doc.select("body").first()!
let rows = try! tables.select("li")
let text = try! tables.html()
Ingrediants.text = text.HtmlToString
}
}
extension String {
var HtmlToString : String? {
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).string
} catch let error as NSError {print(error.localizedDescription)
return nil
}
}
}
In my swift code, what I am trying to do is turn an html code from a website into a text file or string. I used SwftSoup to first parse the html website, and store the contents in 'table'. All the code for this is located in viewDidLoad. I then proceeded to add an extension that should turn the html into a string which also works. When I used a random website like https://hello.com, the code worked and gave an output. But when I use https://google.com, the code doesn't work. I have also used https://www.google.com/?client=safari but I still get the posted error. Any thoughts on how I can fix this?

How to display HTML document correctly in UITextView

I have an UITextview inside a iOS app, where I want to display a HTML document. I found solutions to transform the HTML document to an NSAttributedString.
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 ?? ""
}
}
Now I am struggling with the fact, that the HTML document is not displayed as it should be.
For example I want to display this HTML-example inside my UITextView: https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_example_website
It should look like this:
HTML document in browser
But it looks like this:
HTML document on iPad emulator inside UITextView
What am I doing wrong?

I think it better to display it in WKWebView WKWebKit Offical Documentation

Does NSHTMLTextDocumentType support HTML table?

In my app, i want to display a text in a UILabel. I use HTML to store the text in my data base to dynamically from my text in my app. I actually use this (Swift 3.2, iOS 8+) :
if let data = text.data(using: .utf8) {
let htmlString = try? NSMutableAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue], documentAttributes: nil)
self.textLabel.attributedText = htmlString
}
It's work great for the HTML stuff i used like
<b>Text</b>
<i>Test</i>
And more...
Now, i want to display a table in my label. This is the HTML code for the table :
<table border="2px solid black">
<tr><th>Symbole</th><th>Å</th><th>↓</th><th>■</th><th>╩</th><th>¬</th><th>▓</th><th>Ø</th><th>±</th><th> º </th><th>¶</th><th>░</th></tr>
<tr><td>Utilisation</td><td>1</td><td>11</td><td>11</td><td>5</td><td>1</td><td>4</td><td>12</td><td>4</td><td>1</td><td>5</td><td>1</td></tr>
</table>
This code displays a table form but there is no border in the table. I want to display the table border like the reel HTML render. It's possible or not ?

Weird issue, I didn't understand why this simple thing didn't work, however I managed to make the border appear by adding a random attribute to the NSAttributedString, which makes me believe it's a NSAttributedString rendering bug.
Here's the function that I used (this is Swift 4 but can be converted to earlier versions):
extension String {
func attributedString() -> NSAttributedString? {
guard let data = self.data(using: String.Encoding.utf8,
allowLossyConversion: false) else { return nil }
let options: [NSAttributedString.DocumentReadingOptionKey : Any] = [
NSAttributedString.DocumentReadingOptionKey.characterEncoding : String.Encoding.utf8.rawValue,
NSAttributedString.DocumentReadingOptionKey.documentType : NSAttributedString.DocumentType.html
]
let htmlString = try? NSMutableAttributedString(data: data, options: options, documentAttributes: nil)
// Removing this line makes the bug reappear
htmlString?.addAttribute(NSAttributedStringKey.backgroundColor, value: UIColor.clear, range: NSMakeRange(0, 1))
return htmlString
}
}

How to load html text in watchkit WKInterfaceLabel in ios?

I have on WKInterfaceLabel in which i can not load HTML Tag like
<h1>Grishneshwar Jyotirling</h1>
and I can't use NSMutableAttributedString so please help me to finding regarding things.

var htmlText = "<h1>Grishneshwar Jyotirling</h1> Grishneshwar Jyotirling"
let attributeText: NSAttributedString?
if let htmlData = htmlText.dataUsingEncoding(NSUnicodeStringEncoding) {
do {
attributeText = try NSAttributedString(data: htmlData , options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType], documentAttributes: nil)
myLabel.setAttributedText(attributeText)
}catch let e as NSError {
print("Couldn't translate \(htmlText): \(e.localizedDescription) ")
}

How to display html formatted text in ios label

I would like to display html formatted text on a UILabel in IOS.
In Android, it has api like this .setText(Html.fromHtml(somestring));
Set TextView text from html-formatted string resource in XML
I would like to know what / if there is an equivalent in ios?
I search and find this thread:
How to show HTML text from API on the iPhone?
But it suggests using UIWebView. I need to display html formatted string in each table cell, so I think have 1 webview per row seems a bit heavy.
Is that any other alternative?
Thank you.

Swift 3.0
do {
let attrStr = try NSAttributedString(
data: "<b><i>text</i></b>".data(using: String.Encoding.unicode, allowLossyConversion: true)!,
options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
documentAttributes: nil)
label.attributedText = attrStr
} catch let error {
}

for Swift 2.0:
var attrStr = try! NSAttributedString(
data: "<b><i>text</i></b>".dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true)!,
options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
documentAttributes: nil)
label.attributedText = attrStr

Swift 4
import UIKit
let htmlString = "<html><body> Some <b>html</b> string </body></html>"
// works even without <html><body> </body></html> tags, BTW
let data = htmlString.data(using: String.Encoding.unicode)! // mind "!"
let attrStr = try? NSAttributedString( // do catch
data: data,
options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
documentAttributes: nil)
// suppose we have an UILabel, but any element with NSAttributedString will do
label.attributedText = attrStr
Supplement: controlling the font of resulting formatted string
To use properly scaled (i.e. with respect to user settings) system (or any other) font you may do the following.
let newFont = UIFontMetrics.default.scaledFont(for: UIFont.systemFont(ofSize: UIFont.systemFontSize)) // The same is possible for custom font.
let mattrStr = NSMutableAttributedString(attributedString: attrStr!)
mattrStr.beginEditing()
mattrStr.enumerateAttribute(.font, in: NSRange(location: 0, length: mattrStr.length), options: .longestEffectiveRangeNotRequired) { (value, range, _) in
if let oFont = value as? UIFont, let newFontDescriptor = oFont.fontDescriptor.withFamily(newFont.familyName).withSymbolicTraits(oFont.fontDescriptor.symbolicTraits) {
let nFont = UIFont(descriptor: newFontDescriptor, size: newFont.pointSize)
mattrStr.removeAttribute(.font, range: range)
mattrStr.addAttribute(.font, value: nFont, range: range)
}
}
mattrStr.endEditing()
label.attributedText = mattrStr

You could try an attributed string:
var attrStr = NSAttributedString(
data: "<b><i>text</i></b>".dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true),
options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
documentAttributes: nil,
error: nil)
label.attributedText = attrStr

Objective-C Version:
NSError *error = nil;
NSAttributedString *attributedString = [[NSAttributedString alloc] initWithData:contentData
options:#{NSDocumentTypeDocumentAttribute : NSHTMLTextDocumentType}
documentAttributes:nil error:&error];
This is just the Objective-C conversion of the above answers. All the answers above are right and reference taken from the above answers for this.

For me, Paul's answer worked. But for custom fonts I had to put following hack.
//Please take care of force unwrapping
let data = htmlString.data(using: String.Encoding.unicode)!
let mattrStr = try! NSMutableAttributedString(
data: data,
options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
documentAttributes: nil)
let normalFont = UIFontMetrics.default.scaledFont(for: UIFont(name: "NormalFontName", size: 15.0)!)//
let boldFont = UIFontMetrics.default.scaledFont(for: UIFont(name: "BoldFontName", size: 15.0)!)
mattrStr.beginEditing()
mattrStr.enumerateAttribute(.font, in: NSRange(location: 0, length: mattrStr.length), options: .longestEffectiveRangeNotRequired) { (value, range, _) in
if let oFont = value as? UIFont{
mattrStr.removeAttribute(.font, range: range)
if oFont.fontName.contains("Bold"){
mattrStr.addAttribute(.font, value: boldFont, range: range)
}
else{
mattrStr.addAttribute(.font, value: normalFont, range: range)
}
}
}

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.