as a quick example the public contacts API has been ported over as a service hosted within the server container

lib/contactsmanager.php

@@ -0,0 +1,145 @@
+<?php
+/**
+ * ownCloud
+ *
+ * @author Thomas Müller
+ * @copyright 2013 Thomas Müller thomas.mueller@tmit.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC {
+
+	class ContactsManager implements \OCP\Core\Contacts\IManager {
+
+		/**
+		 * This function is used to search and find contacts within the users address books.
+		 * In case $pattern is empty all contacts will be returned.
+		 *
+		 * @param string $pattern which should match within the $searchProperties
+		 * @param array $searchProperties defines the properties within the query pattern should match
+		 * @param array $options - for future use. One should always have options!
+		 * @return array of contacts which are arrays of key-value-pairs
+		 */
+		public function search($pattern, $searchProperties = array(), $options = array()) {
+			$result = array();
+			foreach($this->address_books as $address_book) {
+				$r = $address_book->search($pattern, $searchProperties, $options);
+				$result = array_merge($result, $r);
+			}
+
+			return $result;
+		}
+
+		/**
+		 * This function can be used to delete the contact identified by the given id
+		 *
+		 * @param object $id the unique identifier to a contact
+		 * @param $address_book_key
+		 * @return bool successful or not
+		 */
+		public function delete($id, $address_book_key) {
+			if (!array_key_exists($address_book_key, $this->address_books))
+				return null;
+
+			$address_book = $this->address_books[$address_book_key];
+			if ($address_book->getPermissions() & \OCP\PERMISSION_DELETE)
+				return null;
+
+			return $address_book->delete($id);
+		}
+
+		/**
+		 * This function is used to create a new contact if 'id' is not given or not present.
+		 * Otherwise the contact will be updated by replacing the entire data set.
+		 *
+		 * @param array $properties this array if key-value-pairs defines a contact
+		 * @param $address_book_key string to identify the address book in which the contact shall be created or updated
+		 * @return array representing the contact just created or updated
+		 */
+		public function createOrUpdate($properties, $address_book_key) {
+
+			if (!array_key_exists($address_book_key, $this->address_books))
+				return null;
+
+			$address_book = $this->address_books[$address_book_key];
+			if ($address_book->getPermissions() & \OCP\PERMISSION_CREATE)
+				return null;
+
+			return $address_book->createOrUpdate($properties);
+		}
+
+		/**
+		 * Check if contacts are available (e.g. contacts app enabled)
+		 *
+		 * @return bool true if enabled, false if not
+		 */
+		public function isEnabled() {
+			return !empty($this->address_books);
+		}
+
+		/**
+		 * @param \OCP\IAddressBook $address_book
+		 */
+		public function registerAddressBook(\OCP\IAddressBook $address_book) {
+			$this->address_books[$address_book->getKey()] = $address_book;
+		}
+
+		/**
+		 * @param \OCP\IAddressBook $address_book
+		 */
+		public function unregisterAddressBook(\OCP\IAddressBook $address_book) {
+			unset($this->address_books[$address_book->getKey()]);
+		}
+
+		/**
+		 * @return array
+		 */
+		public function getAddressBooks() {
+			$result = array();
+			foreach($this->address_books as $address_book) {
+				$result[$address_book->getKey()] = $address_book->getDisplayName();
+			}
+
+			return $result;
+		}
+
+		/**
+		 * removes all registered address book instances
+		 */
+		public function clear() {
+			$this->address_books = array();
+		}
+
+		/**
+		 * @var \OCP\IAddressBook[] which holds all registered address books
+		 */
+		private $address_books = array();
+
+		/**
+		 * In order to improve lazy loading a closure can be registered which will be called in case
+		 * address books are actually requested
+		 *
+		 * @param string $key
+		 * @param \Closure $callable
+		 */
+		function register($key, \Closure $callable)
+		{
+			//
+			//TODO: implement me
+			//
+		}
+	}
+}

lib/public/contacts.php

@@ -90,13 +90,8 @@ namespace OCP {
 		 * @return array of contacts which are arrays of key-value-pairs
 		 */
 		public static function search($pattern, $searchProperties = array(), $options = array()) {
-			$result = array();
-			foreach(self::$address_books as $address_book) {
-				$r = $address_book->search($pattern, $searchProperties, $options);
-				$result = array_merge($result, $r);
-			}
-
-			return $result;
+			$cm = \OC::$server->getContactsManager();
+			return $cm->search($pattern, $searchProperties, $options);
 		}
 
 		/**
@@ -107,14 +102,8 @@ namespace OCP {
 		 * @return bool successful or not
 		 */
 		public static function delete($id, $address_book_key) {
-			if (!array_key_exists($address_book_key, self::$address_books))
-				return null;
-
-			$address_book = self::$address_books[$address_book_key];
-			if ($address_book->getPermissions() & \OCP\PERMISSION_DELETE)
-				return null;
-
-			return $address_book->delete($id);
+			$cm = \OC::$server->getContactsManager();
+			return $cm->delete($id, $address_book_key);
 		}
 
 		/**
@@ -126,15 +115,8 @@ namespace OCP {
 		 * @return array representing the contact just created or updated
 		 */
 		public static function createOrUpdate($properties, $address_book_key) {
-
-			if (!array_key_exists($address_book_key, self::$address_books))
-				return null;
-
-			$address_book = self::$address_books[$address_book_key];
-			if ($address_book->getPermissions() & \OCP\PERMISSION_CREATE)
-				return null;
-
-			return $address_book->createOrUpdate($properties);
+			$cm = \OC::$server->getContactsManager();
+			return $cm->search($properties, $address_book_key);
 		}
 
 		/**
@@ -143,45 +125,40 @@ namespace OCP {
 		 * @return bool true if enabled, false if not
 		 */
 		public static function isEnabled() {
-			return !empty(self::$address_books);
+			$cm = \OC::$server->getContactsManager();
+			return $cm->isEnabled();
 		}
 
 		/**
 		 * @param \OCP\IAddressBook $address_book
 		 */
 		public static function registerAddressBook(\OCP\IAddressBook $address_book) {
-			self::$address_books[$address_book->getKey()] = $address_book;
+			$cm = \OC::$server->getContactsManager();
+			return $cm->registerAddressBook($address_book);
 		}
 
 		/**
 		 * @param \OCP\IAddressBook $address_book
 		 */
 		public static function unregisterAddressBook(\OCP\IAddressBook $address_book) {
-			unset(self::$address_books[$address_book->getKey()]);
+			$cm = \OC::$server->getContactsManager();
+			return $cm->unregisterAddressBook($address_book);
 		}
 
 		/**
 		 * @return array
 		 */
 		public static function getAddressBooks() {
-			$result = array();
-			foreach(self::$address_books as $address_book) {
-				$result[$address_book->getKey()] = $address_book->getDisplayName();
-			}
-
-			return $result;
+			$cm = \OC::$server->getContactsManager();
+			return $cm->getAddressBooks();
 		}
 
 		/**
 		 * removes all registered address book instances
 		 */
 		public static function clear() {
-			self::$address_books = array();
+			$cm = \OC::$server->getContactsManager();
+			$cm->clear();
 		}
-
-		/**
-		 * @var \OCP\IAddressBook[] which holds all registered address books
-		 */
-		private static $address_books = array();
 	}
 }

lib/public/core/contacts/imanager.php

@@ -0,0 +1,150 @@
+<?php
+/**
+ * ownCloud
+ *
+ * @author Thomas Müller
+ * @copyright 2013 Thomas Müller thomas.mueller@tmit.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * Public interface of ownCloud for apps to use.
+ * Contacts Class
+ *
+ */
+
+// use OCP namespace for all classes that are considered public.
+// This means that they should be used by apps instead of the internal ownCloud classes
+namespace OCP\Core\Contacts {
+
+	/**
+	 * This class provides access to the contacts app. Use this class exclusively if you want to access contacts.
+	 *
+	 * Contacts in general will be expressed as an array of key-value-pairs.
+	 * The keys will match the property names defined in https://tools.ietf.org/html/rfc2426#section-1
+	 *
+	 * Proposed workflow for working with contacts:
+	 *  - search for the contacts
+	 *  - manipulate the results array
+	 *  - createOrUpdate will save the given contacts overwriting the existing data
+	 *
+	 * For updating it is mandatory to keep the id.
+	 * Without an id a new contact will be created.
+	 *
+	 */
+	interface IManager {
+
+		/**
+		 * This function is used to search and find contacts within the users address books.
+		 * In case $pattern is empty all contacts will be returned.
+		 *
+		 * Example:
+		 *  Following function shows how to search for contacts for the name and the email address.
+		 *
+		 *		public static function getMatchingRecipient($term) {
+		 *			$cm = \OC:$server->getContactsManager();
+		 *			// The API is not active -> nothing to do
+		 *			if (!$cm->isEnabled()) {
+		 *				return array();
+		 *			}
+		 *
+		 *			$result = $cm->search($term, array('FN', 'EMAIL'));
+		 *			$receivers = array();
+		 *			foreach ($result as $r) {
+		 *				$id = $r['id'];
+		 *				$fn = $r['FN'];
+		 *				$email = $r['EMAIL'];
+		 *				if (!is_array($email)) {
+		 *					$email = array($email);
+		 *				}
+		 *
+		 *				// loop through all email addresses of this contact
+		 *				foreach ($email as $e) {
+		 *				$displayName = $fn . " <$e>";
+		 *				$receivers[] = array(
+		 *					'id'    => $id,
+		 *					'label' => $displayName,
+		 *					'value' => $displayName);
+		 *				}
+		 *			}
+		 *
+		 *			return $receivers;
+		 *		}
+		 *
+		 *
+		 * @param string $pattern which should match within the $searchProperties
+		 * @param array $searchProperties defines the properties within the query pattern should match
+		 * @param array $options - for future use. One should always have options!
+		 * @return array of contacts which are arrays of key-value-pairs
+		 */
+		function search($pattern, $searchProperties = array(), $options = array());
+
+		/**
+		 * This function can be used to delete the contact identified by the given id
+		 *
+		 * @param object $id the unique identifier to a contact
+		 * @param $address_book_key
+		 * @return bool successful or not
+		 */
+		function delete($id, $address_book_key);
+
+		/**
+		 * This function is used to create a new contact if 'id' is not given or not present.
+		 * Otherwise the contact will be updated by replacing the entire data set.
+		 *
+		 * @param array $properties this array if key-value-pairs defines a contact
+		 * @param $address_book_key string to identify the address book in which the contact shall be created or updated
+		 * @return array representing the contact just created or updated
+		 */
+		function createOrUpdate($properties, $address_book_key);
+
+		/**
+		 * Check if contacts are available (e.g. contacts app enabled)
+		 *
+		 * @return bool true if enabled, false if not
+		 */
+		function isEnabled();
+
+		/**
+		 * @param \OCP\IAddressBook $address_book
+		 */
+		function registerAddressBook(\OCP\IAddressBook $address_book);
+
+		/**
+		 * @param \OCP\IAddressBook $address_book
+		 */
+		function unregisterAddressBook(\OCP\IAddressBook $address_book);
+
+		/**
+		 * In order to improve lazy loading a closure can be registered which will be called in case
+		 * address books are actually requested
+		 *
+		 * @param string $key
+		 * @param \Closure $callable
+		 */
+		function register($key, \Closure $callable);
+
+		/**
+		 * @return array
+		 */
+		function getAddressBooks();
+
+		/**
+		 * removes all registered address book instances
+		 */
+		function clear();
+	}
+}

lib/public/core/iservercontainer.php

@@ -11,4 +11,8 @@ namespace OCP\Core;
  */
 interface IServerContainer {
 
+	/**
+	 * @return \OCP\Core\Contacts\IManager
+	 */
+	function getContactsManager();
 }

lib/server.php

@@ -2,6 +2,7 @@
 
 namespace OC;
 
+use OC\AppFramework\Utility\SimpleContainer;
 use OCP\Core\IServerContainer;
 
 /**
@@ -10,6 +11,18 @@ use OCP\Core\IServerContainer;
  *
  * TODO: hookup all manager classes
  */
-class Server implements IServerContainer {
+class Server extends SimpleContainer implements IServerContainer {
 
+	function __construct() {
+		$this->registerService('ContactsManager', function($c){
+			return new ContactsManager();
+		});
+	}
+
+	/**
+	 * @return \OCP\Core\Contacts\IManager
+	 */
+	function getContactsManager() {
+		return $this->query('ContactsManager');
+	}
 }