+ // NOTE! plugins here MUST assign output to template
+ // and NOT echo anything directly!! A common
+ // approach is if a plugin decides it needs to
+ // put something at page-top after the standard
+ // SM page header, to dynamically add itself to
+ // the page_header_bottom and/or compose_header_bottom
+ // hooks for the current page request. See
+ // the Sent Confirmation v1.7 or Restrict Senders v1.2
+ // plugins for examples of this approach.
+ ob_start();
+ $temp = array(&$header_tags);
+ do_hook('generic_header', $temp);
+ $output = ob_get_contents();
+ ob_end_clean();
+ // plugin authors can debug their errors with one of the following:
+ //sm_print_r($output);
+ //echo $output;
+ if (!empty($output)) trigger_error('A plugin on the "generic_header" hook has attempted to output directly to the browser', E_USER_ERROR);