================
 Horde_Registry
================

**This information is valid for Horde 3 only.**

Registry usage example:

::

 require_once HORDE_BASE . 'Horde/Registry.php';
 
 // The Registry has a singleton method that should be used to ensure
 // that there is only ever one instance of the Registry during a request.
 $registry = &Registry::singleton();
 
 // All applications should put themselves on the application stack when they start running
 // This also takes care of reading the application's configuration file.
 $registry->pushApp('curapp');
 
 // When an app is finished, pop it off the application stack
 // This also returns the global $conf variable to that of the previous application.
 $registry->popApp();
 
 // Routines can determine the current app:
 $curapp = $registry->getApp();
 
 // Find out if an application allows access for the current user (may be a guest user)
 if ($registry->hasPermission('app')) {
     // access allowed
 }

Creating the Registry object, one can control how and if a session is started. Note that this only works if calling Registry::singleton() for the first time.

::

 // Let the registry start a regular session.
 $registry = &Registry::singleton();
 
 // Let the registry start a readonly session.
 $registry = &Registry::singleton(HORDE_SESSION_READONLY);
 
 // Don't let the registry start a session.
 $registry = &Registry::singleton(HORDE_SESSION_NONE);

The Registry lets you generate links to other apps

::

 require_once HORDE_BASE . 'Horde/Registry.php';
 $registry = &Registry::singleton();
 
 // Check to see if the functionality we want is there
 if (!$registry->hasMethod('mail/compose')) {
     echo 'no mail/compose method defined';
     exit;
 }
 
 // Generate the link
 echo $registry->link('mail/compose', array('to' => 'foo@example.com', 'subject' => 'bar'));

The Registry also lets you invoke methods in other applications

::

 require_once HORDE_BASE . 'Horde/Registry.php';
 $registry = &Registry::singleton();
 
 // Check to see if the functionality we want is there
 if (!$registry->hasMethod('contacts/search')) {
     echo 'no contacts/search method defined';
     exit;
 }
 
 // The contacts/search method takes two arrays; one of names, one of addressbooks
 $args = array('sources' => array('myldap'),
               'names' => array('Chuck'),
               'fields' => array('name', 'email'));
 $results = $registry->call('contacts/search', $args);
 
 // Using Horde 3.1 and PHP 5, calling API methods is even more elegant:
 $results = $registry->contacts->search($args);