How do I decode HTML entities in Swift?

html-entities, json, swift

Solution

This answer was last revised for Swift 5.2 and iOS 13.4 SDK.

There's no straightforward way to do that, but you can use `NSAttributedString` magic to make this process as painless as possible (be warned that this method will strip all HTML tags as well).

Remember to initialize `NSAttributedString` from main thread only. It uses WebKit to parse HTML underneath, thus the requirement.

// This is a[0]["title"] in your case
let htmlEncodedString = "The Weeknd <em>&#8216;King Of The Fall&#8217;</em>"

guard let data = htmlEncodedString.data(using: .utf8) else {
    return
}

let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
    .documentType: NSAttributedString.DocumentType.html,
    .characterEncoding: String.Encoding.utf8.rawValue
]

guard let attributedString = try? NSAttributedString(data: data, options: options, documentAttributes: nil) else {
    return
}

// The Weeknd ‘King Of The Fall’
let decodedString = attributedString.string

extension String {

    init?(htmlEncodedString: String) {

        guard let data = htmlEncodedString.data(using: .utf8) else {
            return nil
        }

        let options: [NSAttributedString.DocumentReadingOptionKey: Any] = [
            .documentType: NSAttributedString.DocumentType.html,
            .characterEncoding: String.Encoding.utf8.rawValue
        ]

        guard let attributedString = try? NSAttributedString(data: data, options: options, documentAttributes: nil) else {
            return nil
        }

        self.init(attributedString.string)

    }

}

let encodedString = "The Weeknd <em>&#8216;King Of The Fall&#8217;</em>"
let decodedString = String(htmlEncodedString: encodedString)

Problem

I am pulling a JSON file from a site and one of the strings received is: ``` The Weeknd &#8216;King Of The Fall&#8217; [Video Premiere] | @TheWeeknd | #SoPhi ``` How can I convert things like `&#8216` into the correct characters? I've made a Xcode Playground to demonstrate it: ``` import UIKit var error: NSError? let blogUrl: NSURL = NSURL.URLWithString("http://sophisticatedignorance.net/api/get_recent_summary/") let jsonData = NSData(contentsOfURL: blogUrl) let dataDictionary = NSJSONSerialization.JSONObjectWithData(jsonData, options: nil, error: &error) as NSDictionary var a = dataDictionary["posts"] as NSArray println(a[0]["title"]) ```

Original source

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