Using Google Analytics on an image

Question

Basically I want to run the Google Analytics on the server and not show the 1px .GIF (the reason for this is that I want to display an image without it being in HTML but as a Content-type: image/jpeg

    $GA_ACCOUNT = "MO-3845491-5";
      $GA_PIXEL = "ga.php";

      function googleAnalyticsGetImageUrl() {
        global $GA_ACCOUNT, $GA_PIXEL;
        $url = "";
        $url .= $GA_PIXEL . "?";
        $url .= "utmac=" . $GA_ACCOUNT;
        $url .= "&utmn=" . rand(0, 0x7fffffff);

        $referer = $_SERVER["HTTP_REFERER"];
        $query = $_SERVER["QUERY_STRING"];
        $path = $_SERVER["REQUEST_URI"];

        if (empty($referer)) {
          $referer = "-";
        }
        $url .= "&utmr=" . urlencode($referer);

        if (!empty($path)) {
          $url .= "&utmp=" . urlencode($path);
        }

        $url .= "&guid=ON";

        return $url;
      }

$googleAnalyticsImageUrl = googleAnalyticsGetImageUrl();
  //echo '<img src="' . $googleAnalyticsImageUrl . '" />';
  //open the google script with all our settings to generate the 1px x 1px blank gif which reports to GA
  $handle = fopen ($googleAnalyticsImageUrl, "r");
  $test = fgets($handle);
  echo $test;
  fclose($handle);  

//Pretend this page was a jpg image all along and get the jpg and return it.
$imageurl = fopen ('http://www.default.com/test.jpg', "r"); //this is where the real file should be located
while (!feof ($imageurl)) {
 $image = fgets($imageurl, 4096);
 header('Content-type: image/jpeg');
 echo $image;
}
fclose($imageurl);

Any help would be greatly appreciated as I am very new to GA

Answer 1

I can't comment on whether it is possible to trigger a request to GA that way, but you seem to have done your homework and the GA call looks fair enough.

To make this work, as far as I can see, the only thing is to not output the GA image's content, as that will screw up your JPG. So remove

 echo $test;

I can't see anything else wrong with it - if it still doesn't work, you'll have to add some info about what the problem is.

Consider though that even if this method works, passing a lot of images through PHP can be a strain on the server, because a PHP interpreter instance is opened for every image request, and caching is going to be a problem if you want to count all views.

Have you considered triggering the GA "hit" event using JavaScript from the parent HTML page? Or is that not reliable enough?