There's a DOMParser as a part of platform api, that I've been using for maaany years for this. https://developer.mozilla.org/en-US/docs/Web/API/DOMParser https

There's a DOMParser as a part of platform api, that I've been using for maaany years for this. https://developer.mozilla.org/en-US/docs/Web/API/DOMParser https://developer.mozilla.org/en-US/docs/Web/API/DOMParser On top you just write some recursive tree sifting whitelist based function, for your expected input.