Implement default functions in OC_Group backend

Simplifies calling these functions, and makes code simpler

functions:
inGroup
getUserGroups
getGroups
usersInGroup

lib/group.php

@@ -84,7 +84,7 @@ class OC_Group {
 		OC_Hook::emit( "OC_Group", "pre_createGroup", array( "run" => &$run, "gid" => $gid ));
 
 		if($run){
-			//create the user in the first backend that supports creating users
+			//create the group in the first backend that supports creating groups
 			foreach(self::$_usedBackends as $backend){
 				if(!$backend->implementsActions(OC_GROUP_BACKEND_CREATE_GROUP))
 					continue;
@@ -141,9 +141,6 @@ class OC_Group {
 	 */
 	public static function inGroup( $uid, $gid ){
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_IN_GROUP))
-				continue;
-
 			if($backend->inGroup($uid,$gid)){
 				return true;
 			}
@@ -224,9 +221,6 @@ class OC_Group {
 	public static function getUserGroups( $uid ){
 		$groups=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_USER_GROUPS))
-				continue;
-
 			$groups=array_merge($backend->getUserGroups($uid),$groups);
 		}
 		return $groups;
@@ -241,9 +235,6 @@ class OC_Group {
 	public static function getGroups(){
 		$groups=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_GROUPS))
-				continue;
-
 			$groups=array_merge($backend->getGroups(),$groups);
 		}
 		return $groups;
@@ -270,9 +261,6 @@ class OC_Group {
 	public static function usersInGroup($gid){
 		$users=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_USERS))
-				continue;
-
 			$users=array_merge($backend->usersInGroup($gid),$users);
 		}
 		return $users;

lib/group/backend.php

@@ -31,12 +31,8 @@ define('OC_GROUP_BACKEND_NOT_IMPLEMENTED',   -501);
  */
 define('OC_GROUP_BACKEND_CREATE_GROUP',      0x00000001);
 define('OC_GROUP_BACKEND_DELETE_GROUP',      0x00000010);
-define('OC_GROUP_BACKEND_IN_GROUP',          0x00000100);
-define('OC_GROUP_BACKEND_ADD_TO_GROUP',      0x00001000);
-define('OC_GROUP_BACKEND_REMOVE_FROM_GOUP',  0x00010000);
-define('OC_GROUP_BACKEND_GET_USER_GROUPS',   0x00100000);
-define('OC_GROUP_BACKEND_GET_USERS',         0x01000000);
-define('OC_GROUP_BACKEND_GET_GROUPS',        0x10000000);
+define('OC_GROUP_BACKEND_ADD_TO_GROUP',      0x00000100);
+define('OC_GROUP_BACKEND_REMOVE_FROM_GOUP',  0x00001000);
 
 /**
  * Abstract base class for user management
@@ -45,12 +41,8 @@ abstract class OC_Group_Backend {
 	protected $possibleActions = array(
 		OC_GROUP_BACKEND_CREATE_GROUP => 'createGroup',
 		OC_GROUP_BACKEND_DELETE_GROUP => 'deleteGroup',
-		OC_GROUP_BACKEND_IN_GROUP => 'inGroup',
 		OC_GROUP_BACKEND_ADD_TO_GROUP => 'addToGroup',
 		OC_GROUP_BACKEND_REMOVE_FROM_GOUP => 'removeFromGroup',
-		OC_GROUP_BACKEND_GET_USER_GROUPS => 'getUserGroups',
-		OC_GROUP_BACKEND_GET_USERS => 'usersInGroup',
-		OC_GROUP_BACKEND_GET_GROUPS => 'getGroups'
 	);
 	
 	/**
@@ -83,15 +75,55 @@ abstract class OC_Group_Backend {
 		return (bool)($this->getSupportedActions() & $actions);
 	}
 
+	/**
+	 * @brief is user in group?
+	 * @param $uid uid of the user
+	 * @param $gid gid of the group
+	 * @returns true/false
+	 *
+	 * Checks whether the user is member of a group or not.
+	 */
+	public static function inGroup($uid, $gid){
+		return in_array($gid, $this->getUserGroups($uid));
+	}
+
+	/**
+	 * @brief Get all groups a user belongs to
+	 * @param $uid Name of the user
+	 * @returns array with group names
+	 *
+	 * This function fetches all groups a user belongs to. It does not check
+	 * if the user exists at all.
+	 */
+	public static function getUserGroups($uid){
+		return array();
+	}
+
+	/**
+	 * @brief get a list of all groups
+	 * @returns array with group names
+	 *
+	 * Returns a list with all groups
+	 */
+	public static function getGroups(){
+		return array();
+	}
+
 	/**
 	 * check if a group exists
 	 * @param string $gid
 	 * @return bool
 	 */
 	public function groupExists($gid){
-		if(!$this->implementsActions(OC_GROUP_BACKEND_GET_GROUPS)){
-			return false;
-		}
 		return in_array($gid, $this->getGroups());
 	}
+
+	/**
+	 * @brief get a list of all users in a group
+	 * @returns array with user ids
+	 */
+	public static function usersInGroup($gid){
+		return array();
+	}
+
 }

lib/group/example.php

@@ -93,6 +93,13 @@ abstract class OC_Group_Example {
 	 */
 	public static function getGroups(){}
 
+	/**
+	 * check if a group exists
+	 * @param string $gid
+	 * @return bool
+	 */
+	public function groupExists($gid){}
+
 	/**
 	 * @brief get a list of all users in a group
 	 * @returns array with user ids