Restrict audience to groups where user is manager or group admin

Hi, I've patched og.module with some custom code, and was hoping if any coders out there could give me suggestions or feedback about whether I did this correctly. My php skills is basic, so I may or may not have coded it well or correctly. Rather than patching og.module, should this be done in template.php? (and how do I do this?)

Basically, I'm using drupal as a course management system, where teachers can create groups (courses), and add lessons to their groups. But if a teacher adds another teacher as a subscriber to the course, then the other teacher will also be able to add lessons to the course. I don't want this, because other teachers should be only able to observe, rather than post. In order to solve this I wrote the below code change in og.module. However, I would like added teachers who have been designated as 'group admins' to be able to post lessons, but not added teachers who are not admins.

In my code, I use $group->uid == $user->uid to check if user is the owner of the group. However I would prefer to just check if they have the 'group admin' permission. Is there a function or easy way to do this? Here is my full code:

/**
 * Confirm og unsubscription submit handler
 */
function og_confirm_unsubscribe_submit($form_id, $form_values) {
  og_delete_subscription($form_values['gid'], $form_values['uid']);
  drupal_set_message(t('User unsubscribed from group.'));
  return "node/$gid";
}


// since a user's subscriptions are loaded into $user object, this function is only occassionally useful to get group subs for users other than the current user
// even then, it often makes sense to call user_load() instead of this function.
// load all subscriptions for a given user
function og_get_subscriptions($uid, $min_is_active = 1) {
  static $subscriptions = array();

/* Original og code
  if (!isset($subscriptions[$uid][$min_is_active])) {
    $sql = "SELECT n.title, n.type, n.status, ou.* FROM {og_uid} ou INNER JOIN {node} n ON ou.nid = n.nid WHERE ou.uid = %d AND ou.is_active >= %d ORDER BY n.title";
    $result = db_query($sql, $uid, $min_is_active);
    while ($row = db_fetch_array($result)) {
      $subscriptions[$uid][$min_is_active][$row['nid']] = $row;
    }

    if (!isset($subscriptions[$uid][$min_is_active])) {
      $subscriptions[$uid][$min_is_active] = array();
    }
  }
*/
// Replacement code

  if (!isset($subscriptions[$uid][$min_is_active]) && $group->uid == $user->uid) {
    $sql = "SELECT n.title, n.type, n.status, ou.* FROM {og_uid} ou INNER JOIN {node} n ON ou.nid = n.nid WHERE ou.uid = %d AND ou.is_active >= %d AND ou.is_admin = 1 ORDER BY n.title";
    $result = db_query($sql, $uid, $min_is_active);
    while ($row = db_fetch_array($result)) {
      $subscriptions[$uid][$min_is_active][$row['nid']] = $row;
    }

    if (!isset($subscriptions[$uid][$min_is_active])) {
      $subscriptions[$uid][$min_is_active] = array();
    }
  } elseif (!isset($subscriptions[$uid][$min_is_active]) && $group->uid != $user->uid) {
    $sql = "SELECT n.title, n.type, n.status, ou.* FROM {og_uid} ou INNER JOIN {node} n ON ou.nid = n.nid WHERE ou.uid = %d AND ou.is_active >= %d ORDER BY n.title";
    $result = db_query($sql, $uid, $min_is_active);
    while ($row = db_fetch_array($result)) {
      $subscriptions[$uid][$min_is_active][$row['nid']] = $row;
    }

    if (!isset($subscriptions[$uid][$min_is_active])) {
      $subscriptions[$uid][$min_is_active] = array();
    }
  }

  return $subscriptions[$uid][$min_is_active];
}

Thanks for any suggestions of help!

YLC