Generating a QR Code for the Current URL (Google Chart API/Drupal 6.x)

QR code for this URL

Just a few hours ago Google announced the latest feature of their chart API: QR Codes. I always thought that it might be cool to have some QR image of the current URL on my website. So, if someone happens to read one of my articles over at some internet café or at a friend's machine, a QR code might be handy for "bookmarking".

Writing a QR encoder with PHP didn't look like much fun though. And then there is the processing overhead, which can be addressed with caching, but that only means more work. There is also that random string DoS attack vector. Far too much hassle, really. But if Google takes care of all that, it's a piece of cake.

That's why I wrote a little test module for Drupal. It lacks width/height options, but apart from that it's fully functional (as far as I can tell).

<?php
function google_qr_block($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    $blocks = array();
    $blocks[] = array('info' => t('Google QR'),'cache' => BLOCK_CACHE_PER_PAGE);
    return $blocks;
  }
  else if ($op == 'view' && user_access('view Google QR')) {
    $query_string = drupal_query_string_encode($_GET, array('q'));
    if (empty($query_string)) {
      $query_string = NULL;
    }
    $request = trim($_REQUEST['q'], '/');
    $alias = drupal_get_path_alias($request);
    $path = $request;
    if ($alias != $request) {
      $path = $alias;
    }
    $url = urlencode(url($path, array('query' => $query_string, 'absolute' => TRUE)));
    $block = array(
    //'subject' => $url,
    'content' =>
    '<div class="google-qr-block">
    <img src="http://chart.apis.google.com/chart?chs=150x150&amp;cht=qr&amp;chl='.$url.'" alt="QR code for this URL" width="150" height="150"/>
    </div>'
    );
    return $block;
  }
}
?>

Using drupal_urlencode instead of urlencode doesn't work by the way.

If you're wondering why I'm not using that module here yet: Well, the right sidebar is already overcrowded the way it is. The only other sensible region is "Header", but that doesn't work well with the current theme. I'll probably reserve some space for it if I ever get around finishing my custom theme.

Download: Google QR module for Drupal 6.x (1kb)