Swift: strip String from HTML tags

String+HtmlTags.swift

public extension String {

    func htmlTagsStripped() -> String? {
        let stripped = self
            .flattenHtml()
            .trimmingCharacters(in: .whitespacesAndNewlines)
            .removingLinebreaks()
            .removingMultipleSpaces()
            .replacingHtmlCharEntities()
        return stripped
    }
}

public extension String {
    
    func flattenHtml() -> String {
        var html = self
        var text: NSString? = nil
        let scanner = Scanner(string: html)
        while !scanner.isAtEnd {
            scanner.scanUpTo("<", into: nil)
            scanner.scanUpTo(">", into: &text)
            if let text = text {
                html = html.replacingOccurrences(of: "\(text)>", with: " ")
            }
        }
        return html
    }
    
    func removingLinebreaks() -> String {
        return self.replacingOccurrences(of: "\n", with: " ")
    }
    
    func removingMultipleSpaces() -> String {
        return self
            .components(separatedBy: " ")
            .filter { $0.count > 0 }
            .map { String($0) }
            .joined(separator: " ")
    }
    
    func replacingHtmlCharEntities() -> String {
        let map = [
            "&nbsp;" : " ",
            "&lt;" : "<",
            "&gt;" : ">",
            "&amp;" : "&",
            "&quot;" : "\"",
            "&apos;" : "'",
            "&cent;" : "¢",
            "&pound;" : "£",
            "&yen;" : "¥",
            "&euro;" : "€",
            "&copy;" : "©",
            "&reg;" : "®",
            "&rsquo;" : "`"
        ]
        var result = self
        map.enumerated().forEach { (_, element) in
            result = result.replacingOccurrences(of: element.key, with: element.value)
        }
        return result
    }
}