How to report if input is sanitized with OWASP Java HTML Sanitizer

Question

I see in the API that it's possible but I can't figure out how to use that sanitize() method . There's even a forum post where someone says to use it but they don't explain how. In essence I have no idea what CTX means in that method signature. If someone can provide sample code of how to get a list of items that were sanitized that would be appreciated.

Answer 1

You need to setup the HtmlChangeListener to catch all elements that are sanitized. The code then looks something like:

List<String> results = new ArrayList<String>();

HtmlChangeListener<List<String>> htmlChangeListener = new HtmlChangeListener<>()
{
    @Override
    public void discardedTag(List<String> context, String elementName)
    {
        context.add(elementName);
    }

    @Override
    public void discardedAttributes(List<String> context, String tagName, String... attributeNames)
    {
        context.add(tagName);
    }
};

String sanitizedHtml = POLICY_DEFINITION.sanitize(rawHtml, htmlChangeListener, results);
System.out.println("Sanitized elements include: " + String.join(",", results));