检测是否已发送Ajax请求

Question

I just cannot figure out how to check in PHP if an ajax request has been sent (form submission).

neither

if (isset($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest')

nor

if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest')

gets executed.

Here is the javascript code.

$.ajax({
       type: "POST",
       url: 'login.php',
       data: $(this).serialize()
   });

"this" is referring to the form. I have checked it and it is in the correct format username=dean&password=123123

What am I doing wrong?

Answer 1

Add a callback...

  $.ajax({
       type: "POST",
       url: 'login.php',
       data: $(this).serialize(),
       success : function(response){
             console.log(response);
        }
   });

Answer 2

Try to use browser developer tool (FireBug Network panel if you're using Mozilla Firefox), to make sure that the appropriate header is sent. And which version of jQuery are you using? Also, if you are using PHP-FPM as backend for Nginx http server, Nginx may not send some HTTP-headers to backend, depending on it's configuration.