Stuff

/**
* Finds the region in which block content is being rendered.
* Caches node regions by url. Could cause problems if a node
* is on a page twice
* @param int $nid is a node id
* return string of node region location
*/
function tnt_get_region_for_block_content($nid) {
  // create the cache name, be safe
  $cache_name = 'theme_regions_'. check_plain($_GET['q']);

  // retrieve cache
  $data = cache_get($cache_name, 'cache');

  // get data from the cache
  $data = unserialize($data->data);

  // we don't have region data for this node
  if (! $data['nid']) {

          // Get the function call stack and search it for block_list().
          // Reverse it for speed-efficiency.
          //   - There are usually only about 5 fns between block_list() and the bottom of the stack.
          //   - With views there can be 20 fns between block_list() the top of the stack.
          // DON'T MODIFY $stack.  Treat it as read-only.
          $stack = array_reverse(debug_backtrace());
        
          // Search for block_list().
          foreach ($stack as $i => $fn) {
            if ($fn['function'] == 'block_list') {
              // Unfortunately the first argument of block_list() is not the correct region,
              // because block_list() renders and stores all the blocks on it's first invocation.
              // So this doesn't work:
              //$vars['region'] = $fn['args'][0];
        
              // block_list() calls module_invoke() to invoke hook_block() in each module.
              // So module_invoke() is the next function UP in the reversed stack.
              // ($i is 0 for the bottom of the reversed stack.)
              // Store the parameters that module_invoke() was called with.
              $module_invoke_args = $stack[$i + 1]['args'];
        
              // Precautionary measure to save on memory consumption.
              // Probably unnecessary.
              // DON'T MODIFY $stack.
              unset($stack);
        
              // The 1st parameter is the block's module.  4th (last) parameter is the block's delta.
              // Search block_list() for 'module_invoke'.
              // See http://api.drupal.org/api/function/block_list/5
              $module = $module_invoke_args[0];
              $delta = $module_invoke_args[3];
        
              // Get and store the block regions from the database.
              // We'll reuse this data each time, so only do this on the first invocation.
              static $blocks;
              if (!isset($blocks)) {
                $blocks = array();
                $result = db_query("SELECT module, delta, region FROM blocks WHERE theme = '%s'", $GLOBALS['theme_key']);
                while ($row = db_fetch_object($result)) {
                  // Store region by module then delta.
                  $blocks[$row->module][$row->delta] = $row->region;
                }
              }
        
              // Set the region, from the stored regions.
              $return_region =  $blocks[$module][$delta];
            }
          }
        
          // now join the region to the data
          $data = array_merge($data, array($nid => $return_region));
        
          // now cache the data
          cache_set($cache_name, 'cache', serialize($data), CACHE_TEMPORARY);
  }
        return $data[$nid];
}