Encode NSString for XML/HTML

Question

Is there a way to HTML encode a string (NSString) in Objective-C, something along the lines of Server.HtmlEncode in .NET?

Answer 1

I found the only way that uses only built-in functions (not manual parsing) and covers all cases. Requires AppKit/UIKit in addition to Foundation. This is Swift but can easily be Objective-C:

func encodedForHTML() -> String {

    // make a plain attributed string and then use its HTML write functionality
    let attrStr = NSAttributedString(string: self)

    // by default, the document outputs a whole HTML element
    // warning: if default apple implementation changes, this may need to be tweaked
    let options: [NSAttributedString.DocumentAttributeKey: Any] = [
            .documentType: NSAttributedString.DocumentType.html,
            .excludedElements: [
                "html",
                "head",
                "meta",
                "title",
                "style",
                "p",
                "body",
                "font",
                "span"
            ]
    ]

    // generate data and turn into string
    let data = try! attrStr.data(from: NSRange(location: 0, length: attrStr.length), documentAttributes: options)
    let str = String(data: data, encoding: .utf8)!

    // remove