You need to use a different event to get your code in the right place. There are a couple of places you can hook in:
Use the ushahidi_action.header_scripts event:
Event::add('ushahidi_action.header_scripts', array($this, 'AddMetaTags'));
See header.php to see where that hooks in.
Use the ushahidi_filter.header_block event:
See Themes.php for where that hooks in.public function SearchShare(){ Event::add('ushahidi_filter.header_block', array($this, 'AddMetaTags')); } public function AddMetaTags(){ $header = Event::$data; $header .= "Hello World"; Event::$data = $header; }
Neither of these is better/worse than the other, so use whichever you prefer.