Add method to get users by their preference

lib/private/preferences.php

@@ -242,6 +242,28 @@ class Preferences {
 		return $userValues;
 	}
 
+	/**
+	 * Gets the users for a preference
+	 * @param string $app
+	 * @param string $key
+	 * @param string $value
+	 * @return array
+	 */
+	public function getUsersForValue($app, $key, $value) {
+		$users = array();
+
+		$query = 'SELECT `userid` '
+			. ' FROM `*PREFIX*preferences` '
+			. ' WHERE `appid` = ? AND `configkey` = ? AND `configvalue` = ?';
+		$result = $this->conn->executeQuery($query, array($app, $key, $value));
+
+		while ($row = $result->fetch()) {
+			$users[] = $row['userid'];
+		}
+
+		return $users;
+	}
+
 	/**
 	 * Deletes a key
 	 * @param string $user user

tests/lib/preferences.php

@@ -221,6 +221,22 @@ class Test_Preferences_Object extends PHPUnit_Framework_TestCase {
 		$this->assertEquals('someothervalue', $values['AnotherUser']);
 	}
 
+	public function testGetValueUsers()
+	{
+		// Prepare data
+		$query = \OC_DB::prepare('INSERT INTO `*PREFIX*preferences` VALUES(?, ?, ?, ?)');
+		$query->execute(array('SomeUser', 'testGetUsersForValue', 'somekey', 'somevalue'));
+		$query->execute(array('AnotherUser', 'testGetUsersForValue', 'somekey', 'someothervalue'));
+		$query->execute(array('AUser', 'testGetUsersForValue', 'somekey', 'somevalue'));
+
+		$preferences = new OC\Preferences(\OC_DB::getConnection());
+		$this->assertEquals(array('SomeUser', 'AUser'), $preferences->getUsersForValue('testGetUsersForValue', 'somekey', 'somevalue'));
+
+		// Clean DB after the test
+		$query = \OC_DB::prepare('DELETE FROM `*PREFIX*preferences` WHERE `appid` = ?');
+		$query->execute(array('testGetUsersForValue'));
+	}
+
 	public function testDeleteKey()
 	{
 		$connectionMock = $this->getMock('\OC\DB\Connection', array(), array(), '', false);