Detecting Ajax in PHP and making sure request was from my own website

Question

I use my PHP back-end to detect AJAX requests by checking for a value in $_SERVER[\'HTTP_X_REQUESTED_WITH\'].

This gives me a reliable detection, making

Answer 1

David Walsh has a good solution

/* decide what the content should be up here .... */
$content = get_content(); //generic function;

/* AJAX check  */
if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
    /* special ajax here */
    die($content);
}

/* not ajax, do more.... */