ios - Cannot convert value of type NSAttributedString.DocumentAttributeKey to .DocumentReadingOptionKey

Question

I found this string extension somewhere on SO that allows me to turn html code into an attributed string:

func html2AttributedString() -> NSAttributedString {
    return try! NSAttributedString(data: self.data(using: String.Encoding.unicode, allowLossyConversion: true)!, options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType], documentAttributes: nil)
}

It worked fine in Swift 3, but with Swift 4, Xcode complains:

Cannot convert value of type 'NSAttributedString.DocumentAttributeKey' to expected dictionary key type 'NSAttributedString.DocumentReadingOptionKey'

How do I fix this?

question from:https://stackoverflow.com/questions/44390520/cannot-convert-value-of-type-nsattributedstring-documentattributekey-to-documen