Exploring Web Development with PHP, JavaScript, and more

I am finding myself implementing ajax into almost all my projects these days, the benefits are obvious: faster load times, richer interfaces, increased usability, and web 2.0 cred

Ideally AJAX powered sites should offer fallback functionality for those with javascript disabled, so we need a quick way of checking if the page was called via AJAX in our PHP code.

I normally build the following helpful function into my controllers:

function is_ajax() {
  if (
     isset($_SERVER['HTTP_X_REQUESTED_WITH'])
     && 'XMLHttpRequest' == $_SERVER['HTTP_X_REQUESTED_WITH']
    ) {
      return true;
  }
}

So now we can easily serve up some json to our ajax requests, and HTML for users without javascript.

if (is_ajax()) {
	echo json_encode($data);
} else {
	// load HTML view
}

voila.