PHP无法识别AJAX调用

Question

I'm calling a file via jQuery's AJAX method looks like this:

    $is_ajax = $_REQUEST['is_ajax'];
    if(isset($is_ajax) && $is_ajax)
    {
        echo 'its ajax!';
    }
    else echo 'im called, but not via ajax';

and my AJAX call:

jQuery.ajax({
                type: 'POST',
                url: 'my-service.php',
                data: data,
                success: function(response) { 
                    alert(response);
                 }
            });

But alert always shows 'not ajax' message. What am I doing wrong?

Answer 1

Another method

You can simple check whether the request is AJAX or not like this,

/* AJAX check  */
if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
  echo 'its ajax!';
}else{
  echo 'im called, but not via ajax';
}