// Login form class
$controllerFront = Zend_Controller_Front::getInstance();
$returnUrl =  $controllerFront->getRequest()->getRequestUri();
$this->addElement('hidden', 'returnUrl', array(
	'value' => $returnUrl
));

// AuthController
// inside loginAction() - after authentication is successful
$returnUrl = $form->getElement('returnUrl')->getValue();
if (!empty($returnUrl)) {
	$this->_helper->getHelper('Redirector')->setGotoUrl($returnUrl);
}

redirecting back to where the user came from is a very common functionality in login forms. 

technical implementation: 

- have a hidden field (`returnUrl`)
- populated by current url (in Zend Framework, i get this using the request's `getRequestUri()` function)
- in the `AuthController`, if the `returnUrl` field is set, i will redirect the user to that page using the `Redirector` helper.

Zend Framework: Having forms redirect back to page user came from

PHP