sjehuda / Newspaper

First check HEADER, then GET content @7nik.

Call twice to XMLHTTPRequest.

Once with HEAD and XMLHttpRequest.readyState === 2 (HEADERS_RECEIVED) and if page is a Feed; then

Once again with GET and XMLHttpRequest.readyState === 3 (LOADING) or 4 (DONE) when MIME-Type doesn't say ATOM or RSS but we find out that it is.