Magento: Detect if admin is logged in in frontend pages

Question

I have created a magento extension. I want to implement access to the extension. The extension creates a page in frontend and i want only admin to access that page. So basically

Answer 1

The key to be able to use:

// Ensure we're in the admin session namespace for checking the admin user..
Mage::getSingleton('core/session', array('name' => 'adminhtml'))->start();

$admin_logged_in = Mage::getSingleton('admin/session', array('name' => 'adminhtml'))->isLoggedIn();

// ..get back to the original.
Mage::getSingleton('core/session', array('name' => $this->_sessionNamespace))->start();

is that the controller must extends Mage_Adminhtml_Controller_Action

than you can use this code in the preDispatch function.

And setup the routers for this controller in the admin section of your config.xml.