Conditionally load layouts using Observer events From http://prattski.com/2012/04/25/magento-more-flexibility-for-your-layout-updates/ http://stackoverflow.com/questions/11804575/dynamically-insert-into-layout-xml-of-magento

conditional_layout_event

In config.xml

          <controller_action_layout_generate_xml_before>
                <observers>
                    <add_new_layout>
                        <class>wsafreightcommon/observer</class>
                        <method>addNewLayout</method>
                    </add_new_layout>
                </observers>
            </controller_action_layout_generate_xml_before>
            
            
Observer.php 

public function addNewLayout($observer){
    $layout = $observer->getEvent()->getLayout();
    $update = $layout->getUpdate();

    $action = $observer->getEvent()->getAction();
    $fullActionName = $action->getFullActionName();
    
          switch ($fullActionName) {
            case 'adminhtml_sales_order_view':
                $xml = "<reference name='root'><remove name='footer'></remove></reference>";
                $update->addUpdate($xml);
            ...
            break;
          }
    //in case you're going to add some conditional (apply these new layout xml on these action or other things, you can modify it by yourself)

    //here is the pieces of layout xml you're going to load (you get it from database)


    return;
}