summaryrefslogtreecommitdiffstats
path: root/core/css
Commit message (Expand)AuthorAgeFilesLines
* Merge pull request #4136 from nextcloud/expire-date-for-all-sharesMorris Jobke2017-04-072-2/+16
|\
| * Fix share dropdown opacity issueJan-Christoph Borchardt2017-04-071-0/+1
| * Fix font-weight of Unshare entryJan-Christoph Borchardt2017-04-071-2/+2
| * set expire date for all share typesBjoern Schiessle2017-04-031-0/+3
| * allow password protected mail sharesBjoern Schiessle2017-04-031-0/+6
| * allow the user to set a expire date for all sharesBjoern Schiessle2017-04-031-0/+4
* | Increase clickable area of app iconJan-Christoph Borchardt2017-04-071-10/+7
* | proper padding for checkboxes in app-settingsJan-Christoph Borchardt2017-04-041-1/+16
|/
* Add CSS for styling of keyboard shortcuts viewJan-Christoph Borchardt2017-03-301-1/+30
* Merge pull request #4100 from nextcloud/header-indicatorMorris Jobke2017-03-292-2/+26
|\
| * adjust opacity of search and gear icons in headerJan-Christoph Borchardt2017-03-272-2/+7
| * add pointer finger to full clickable app icon areaJan-Christoph Borchardt2017-03-271-0/+1
| * show triangle below user menu too when an entry inside there is activeJan-Christoph Borchardt2017-03-271-0/+18
* | Better styling of the empty content messages in the sidebarJoas Schilling2017-03-281-0/+4
* | Merge pull request #4101 from nextcloud/header-detailMorris Jobke2017-03-281-6/+1
|\ \
| * | show active indicator on current app even when hovering other iconsJan-Christoph Borchardt2017-03-271-6/+1
| |/
* | Merge pull request #4082 from nextcloud/fix-menuJohn Molakvoรฆ2017-03-281-16/+11
|\ \ | |/ |/|
| * highlight active entry in personal info menu againJan-Christoph Borchardt2017-03-271-5/+5
| * Fix pop over menu opacityMorris Jobke2017-03-261-15/+10
* | Merge pull request #4077 from nextcloud/better-navigation-managementMorris Jobke2017-03-261-22/+0
|\ \
| * | Move app management to the settings menuJoas Schilling2017-03-261-23/+1
| |/
* | Merge pull request #4075 from nextcloud/search-hover-feedbackLukas Reschke2017-03-261-1/+5
|\ \
| * | add hover feedback for search, and opacity on useJan-Christoph Borchardt2017-03-261-1/+5
| |/
* | Merge pull request #4074 from nextcloud/replace-name-with-iconMorris Jobke2017-03-262-20/+19
|\ \
| * | replace name in top right with icon for less noiseJan-Christoph Borchardt2017-03-262-20/+19
| |/
* / fix emptycontent font color lightnessJan-Christoph Borchardt2017-03-261-1/+1
|/
* Fix appmenu issuesJulius Hรคrtl2017-03-241-1/+2
* Fix position of triangle in app menuMorris Jobke2017-03-211-1/+1
* Merge pull request #3530 from nextcloud/scss-variablesLukas Reschke2017-03-209-248/+223
|\
| * Replace old color occurences with calculationsJulius Haertl2017-03-205-84/+75
| * Make remaining colors depending on $color-main-text and $color-main-backgroundJulius Haertl2017-03-203-21/+19
| * Remove legacy CSSJulius Haertl2017-03-202-45/+1
| * Merge color tones aaaaaa, bebebe, cccccc in bbbbbbJulius Haertl2017-03-204-14/+7
| * Remove grey tintsJulius Haertl2017-03-202-3/+3
| * Remove separate error colorsJulius Haertl2017-03-202-4/+3
| * Extra variable for loading iconsJulius Haertl2017-03-202-8/+7
| * Merge #666 and #777 to #555Julius Haertl2017-03-203-6/+6
| * Use one box-shadow colorJulius Haertl2017-03-203-5/+5
| * Replace #222 with #333Julius Haertl2017-03-202-3/+3
| * Remove unused old #999Julius Haertl2017-03-201-1/+0
| * Merge colorsJulius Haertl2017-03-204-16/+12
| * Remove rgb color valuesJulius Haertl2017-03-205-16/+15
| * Simplify colorsJulius Haertl2017-03-201-22/+24
| * SCSS colors in tooltip.scssJulius Haertl2017-03-201-6/+6
| * SCSS colors in styles.scssJulius Haertl2017-03-201-67/+67
| * SCSS colors in share.scssJulius Haertl2017-03-201-5/+5
| * SCSS colors in multiselect.scssJulius Haertl2017-03-201-11/+11
| * SCSS colors in inputs.scssJulius Haertl2017-03-201-63/+63
| * SCSS colors in icons.scssJulius Haertl2017-03-201-4/+4
| * SCSS colors in apps.scssJulius Haertl2017-03-201-40/+40
708'>708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
<?php
/**
 * @author Adam Williamson <awilliam@redhat.com>
 * @author Andreas Bรถhler <dev@aboehler.at>
 * @author Andreas Fischer <bantu@owncloud.com>
 * @author Arthur Schiwon <blizzz@owncloud.com>
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Bernhard Posselt <dev@bernhard-posselt.com>
 * @author Birk Borkason <daniel.niccoli@gmail.com>
 * @author Bjรถrn SchieรŸle <schiessle@owncloud.com>
 * @author Brice Maron <brice@bmaron.net>
 * @author Christopher Schรคpers <kondou@ts.unde.re>
 * @author Clark Tomlinson <fallen013@gmail.com>
 * @author cmeh <cmeh@users.noreply.github.com>
 * @author Florin Peter <github@florin-peter.de>
 * @author Frank Karlitschek <frank@owncloud.org>
 * @author Georg Ehrke <georg@owncloud.com>
 * @author helix84 <helix84@centrum.sk>
 * @author Individual IT Services <info@individual-it.net>
 * @author Jakob Sack <mail@jakobsack.de>
 * @author Joas Schilling <nickvergessen@owncloud.com>
 * @author Jรถrn Friedrich Dreyer <jfd@butonic.de>
 * @author Lukas Reschke <lukas@owncloud.com>
 * @author Markus Goetz <markus@woboq.com>
 * @author Martin Mattel <martin.mattel@diemattels.at>
 * @author Marvin Thomas Rabe <mrabe@marvinrabe.de>
 * @author Michael Gapczynski <GapczynskiM@gmail.com>
 * @author Michael Gรถhler <somebody.here@gmx.de>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Roeland Jago Douma <rullzer@owncloud.com>
 * @author Stefan Rado <owncloud@sradonia.net>
 * @author Thomas Mรผller <thomas.mueller@tmit.eu>
 * @author Thomas Schmidt <tschmidt@suse.de>
 * @author Thomas Tanghus <thomas@tanghus.net>
 * @author Victor Dubiniuk <dubiniuk@owncloud.com>
 * @author Vincent Chan <plus.vincchan@gmail.com>
 * @author Vincent Petry <pvince81@owncloud.com>
 * @author Volkan Gezer <volkangezer@gmail.com>
 *
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program 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, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

use OCP\IConfig;
use OCP\IGroupManager;
use OCP\IUser;

class OC_Util {
	public static $scripts = array();
	public static $styles = array();
	public static $headers = array();
	private static $rootMounted = false;
	private static $fsSetup = false;

	protected static function getAppManager() {
		return \OC::$server->getAppManager();
	}

	private static function initLocalStorageRootFS() {
		// mount local file backend as root
		$configDataDirectory = \OC::$server->getSystemConfig()->getValue("datadirectory", OC::$SERVERROOT . "/data");
		//first set up the local "root" storage
		\OC\Files\Filesystem::initMountManager();
		if (!self::$rootMounted) {
			\OC\Files\Filesystem::mount('\OC\Files\Storage\Local', array('datadir' => $configDataDirectory), '/');
			self::$rootMounted = true;
		}
	}

	/**
	 * mounting an object storage as the root fs will in essence remove the
	 * necessity of a data folder being present.
	 * TODO make home storage aware of this and use the object storage instead of local disk access
	 *
	 * @param array $config containing 'class' and optional 'arguments'
	 */
	private static function initObjectStoreRootFS($config) {
		// check misconfiguration
		if (empty($config['class'])) {
			\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
		}
		if (!isset($config['arguments'])) {
			$config['arguments'] = array();
		}

		// instantiate object store implementation
		$config['arguments']['objectstore'] = new $config['class']($config['arguments']);
		// mount with plain / root object store implementation
		$config['class'] = '\OC\Files\ObjectStore\ObjectStoreStorage';

		// mount object storage as root
		\OC\Files\Filesystem::initMountManager();
		if (!self::$rootMounted) {
			\OC\Files\Filesystem::mount($config['class'], $config['arguments'], '/');
			self::$rootMounted = true;
		}
	}

	/**
	 * Can be set up
	 *
	 * @param string $user
	 * @return boolean
	 * @description configure the initial filesystem based on the configuration
	 */
	public static function setupFS($user = '') {
		//setting up the filesystem twice can only lead to trouble
		if (self::$fsSetup) {
			return false;
		}

		\OC::$server->getEventLogger()->start('setup_fs', 'Setup filesystem');

		// If we are not forced to load a specific user we load the one that is logged in
		if ($user === null) {
			$user = '';
		} else if ($user == "" && OC_User::isLoggedIn()) {
			$user = OC_User::getUser();
		}

		// load all filesystem apps before, so no setup-hook gets lost
		OC_App::loadApps(array('filesystem'));

		// the filesystem will finish when $user is not empty,
		// mark fs setup here to avoid doing the setup from loading
		// OC_Filesystem
		if ($user != '') {
			self::$fsSetup = true;
		}

		\OC\Files\Filesystem::initMountManager();

		\OC\Files\Filesystem::addStorageWrapper('mount_options', function ($mountPoint, \OCP\Files\Storage $storage, \OCP\Files\Mount\IMountPoint $mount) {
			if ($storage->instanceOfStorage('\OC\Files\Storage\Common')) {
				/** @var \OC\Files\Storage\Common $storage */
				$storage->setMountOptions($mount->getOptions());
			}
			return $storage;
		});

		\OC\Files\Filesystem::addStorageWrapper('enable_sharing', function ($mountPoint, \OCP\Files\Storage $storage, \OCP\Files\Mount\IMountPoint $mount) {
			if (!$mount->getOption('enable_sharing', true)) {
				return new \OC\Files\Storage\Wrapper\PermissionsMask([
					'storage' => $storage,
					'mask' => \OCP\Constants::PERMISSION_ALL - \OCP\Constants::PERMISSION_SHARE
				]);
			}
			return $storage;
		});

		// install storage availability wrapper, before most other wrappers
		\OC\Files\Filesystem::addStorageWrapper('oc_availability', function ($mountPoint, $storage) {
			if (!$storage->instanceOfStorage('\OC\Files\Storage\Shared') && !$storage->isLocal()) {
				return new \OC\Files\Storage\Wrapper\Availability(['storage' => $storage]);
			}
			return $storage;
		});

		\OC\Files\Filesystem::addStorageWrapper('oc_quota', function ($mountPoint, $storage) {
			// set up quota for home storages, even for other users
			// which can happen when using sharing

			/**
			 * @var \OC\Files\Storage\Storage $storage
			 */
			if ($storage->instanceOfStorage('\OC\Files\Storage\Home')
				|| $storage->instanceOfStorage('\OC\Files\ObjectStore\HomeObjectStoreStorage')
			) {
				/** @var \OC\Files\Storage\Home $storage */
				if (is_object($storage->getUser())) {
					$user = $storage->getUser()->getUID();
					$quota = OC_Util::getUserQuota($user);
					if ($quota !== \OCP\Files\FileInfo::SPACE_UNLIMITED) {
						return new \OC\Files\Storage\Wrapper\Quota(array('storage' => $storage, 'quota' => $quota, 'root' => 'files'));
					}
				}
			}

			return $storage;
		});

		OC_Hook::emit('OC_Filesystem', 'preSetup', array('user' => $user));

		//check if we are using an object storage
		$objectStore = \OC::$server->getSystemConfig()->getValue('objectstore', null);
		if (isset($objectStore)) {
			self::initObjectStoreRootFS($objectStore);
		} else {
			self::initLocalStorageRootFS();
		}

		if ($user != '' && !OCP\User::userExists($user)) {
			\OC::$server->getEventLogger()->end('setup_fs');
			return false;
		}

		//if we aren't logged in, there is no use to set up the filesystem
		if ($user != "") {

			$userDir = '/' . $user . '/files';

			//jail the user into his "home" directory
			\OC\Files\Filesystem::init($user, $userDir);

			OC_Hook::emit('OC_Filesystem', 'setup', array('user' => $user, 'user_dir' => $userDir));
		}
		\OC::$server->getEventLogger()->end('setup_fs');
		return true;
	}

	/**
	 * check if a password is required for each public link
	 *
	 * @return boolean
	 */
	public static function isPublicLinkPasswordRequired() {
		$appConfig = \OC::$server->getAppConfig();
		$enforcePassword = $appConfig->getValue('core', 'shareapi_enforce_links_password', 'no');
		return ($enforcePassword === 'yes') ? true : false;
	}

	/**
	 * check if sharing is disabled for the current user
	 * @param IConfig $config
	 * @param IGroupManager $groupManager
	 * @param IUser|null $user
	 * @return bool
	 */
	public static function isSharingDisabledForUser(IConfig $config, IGroupManager $groupManager, $user) {
		if ($config->getAppValue('core', 'shareapi_exclude_groups', 'no') === 'yes') {
			$groupsList = $config->getAppValue('core', 'shareapi_exclude_groups_list', '');
			$excludedGroups = json_decode($groupsList);
			if (is_null($excludedGroups)) {
				$excludedGroups = explode(',', $groupsList);
				$newValue = json_encode($excludedGroups);
				$config->setAppValue('core', 'shareapi_exclude_groups_list', $newValue);
			}
			$usersGroups = $groupManager->getUserGroupIds($user);
			if (!empty($usersGroups)) {
				$remainingGroups = array_diff($usersGroups, $excludedGroups);
				// if the user is only in groups which are disabled for sharing then
				// sharing is also disabled for the user
				if (empty($remainingGroups)) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * check if share API enforces a default expire date
	 *
	 * @return boolean
	 */
	public static function isDefaultExpireDateEnforced() {
		$isDefaultExpireDateEnabled = \OCP\Config::getAppValue('core', 'shareapi_default_expire_date', 'no');
		$enforceDefaultExpireDate = false;
		if ($isDefaultExpireDateEnabled === 'yes') {
			$value = \OCP\Config::getAppValue('core', 'shareapi_enforce_expire_date', 'no');
			$enforceDefaultExpireDate = ($value === 'yes') ? true : false;
		}

		return $enforceDefaultExpireDate;
	}

	/**
	 * Get the quota of a user
	 *
	 * @param string $user
	 * @return int Quota bytes
	 */
	public static function getUserQuota($user) {
		$userQuota = \OC::$server->getUserManager()->get($user)->getQuota();
		if($userQuota === 'none') {
			return \OCP\Files\FileInfo::SPACE_UNLIMITED;
		}else{
			return OC_Helper::computerFileSize($userQuota);
		}
	}

	/**
	 * copies the skeleton to the users /files
	 *
	 * @param String $userId
	 * @param \OCP\Files\Folder $userDirectory
	 */
	public static function copySkeleton($userId, \OCP\Files\Folder $userDirectory) {

		$skeletonDirectory = \OCP\Config::getSystemValue('skeletondirectory', \OC::$SERVERROOT . '/core/skeleton');

		if (!empty($skeletonDirectory)) {
			\OCP\Util::writeLog(
				'files_skeleton',
				'copying skeleton for '.$userId.' from '.$skeletonDirectory.' to '.$userDirectory->getFullPath('/'),
				\OCP\Util::DEBUG
			);
			self::copyr($skeletonDirectory, $userDirectory);
			// update the file cache
			$userDirectory->getStorage()->getScanner()->scan('', \OC\Files\Cache\Scanner::SCAN_RECURSIVE);
		}
	}

	/**
	 * copies a directory recursively by using streams
	 *
	 * @param string $source
	 * @param \OCP\Files\Folder $target
	 * @return void
	 */
	public static function copyr($source, \OCP\Files\Folder $target) {
		$dir = opendir($source);
		while (false !== ($file = readdir($dir))) {
			if (!\OC\Files\Filesystem::isIgnoredDir($file)) {
				if (is_dir($source . '/' . $file)) {
					$child = $target->newFolder($file);
					self::copyr($source . '/' . $file, $child);
				} else {
					$child = $target->newFile($file);
					stream_copy_to_stream(fopen($source . '/' . $file,'r'), $child->fopen('w'));
				}
			}
		}
		closedir($dir);
	}

	/**
	 * @return void
	 */
	public static function tearDownFS() {
		\OC\Files\Filesystem::tearDown();
		self::$fsSetup = false;
		self::$rootMounted = false;
	}

	/**
	 * get the current installed version of ownCloud
	 *
	 * @return array
	 */
	public static function getVersion() {
		OC_Util::loadVersion();
		return \OC::$server->getSession()->get('OC_Version');
	}

	/**
	 * get the current installed version string of ownCloud
	 *
	 * @return string
	 */
	public static function getVersionString() {
		OC_Util::loadVersion();
		return \OC::$server->getSession()->get('OC_VersionString');
	}

	/**
	 * @description get the current installed edition of ownCloud. There is the community
	 * edition that just returns an empty string and the enterprise edition
	 * that returns "Enterprise".
	 * @return string
	 */
	public static function getEditionString() {
		if (OC_App::isEnabled('enterprise_key')) {
			return "Enterprise";
		} else {
			return "";
		}

	}

	/**
	 * @description get the update channel of the current installed of ownCloud.
	 * @return string
	 */
	public static function getChannel() {
		OC_Util::loadVersion();
		return \OC::$server->getSession()->get('OC_Channel');
	}

	/**
	 * @description get the build number of the current installed of ownCloud.
	 * @return string
	 */
	public static function getBuild() {
		OC_Util::loadVersion();
		return \OC::$server->getSession()->get('OC_Build');
	}

	/**
	 * @description load the version.php into the session as cache
	 */
	private static function loadVersion() {
		$timestamp = filemtime(OC::$SERVERROOT . '/version.php');
		if (!\OC::$server->getSession()->exists('OC_Version') or OC::$server->getSession()->get('OC_Version_Timestamp') != $timestamp) {
			require OC::$SERVERROOT . '/version.php';
			$session = \OC::$server->getSession();
			/** @var $timestamp int */
			$session->set('OC_Version_Timestamp', $timestamp);
			/** @var $OC_Version string */
			$session->set('OC_Version', $OC_Version);
			/** @var $OC_VersionString string */
			$session->set('OC_VersionString', $OC_VersionString);
			/** @var $OC_Build string */
			$session->set('OC_Build', $OC_Build);
			
			// Allow overriding update channel
			
			if (\OC::$server->getSystemConfig()->getValue('installed', false)) {
				$channel = \OC::$server->getAppConfig()->getValue('core', 'OC_Channel');
			} else {
				/** @var $OC_Channel string */
				$channel = $OC_Channel;
			}
			
			if (!is_null($channel)) {
				$session->set('OC_Channel', $channel);
			} else {
				/** @var $OC_Channel string */
				$session->set('OC_Channel', $OC_Channel);
			}
		}
	}

	/**
	 * generates a path for JS/CSS files. If no application is provided it will create the path for core.
	 *
	 * @param string $application application to get the files from
	 * @param string $directory directory within this application (css, js, vendor, etc)
	 * @param string $file the file inside of the above folder
	 * @return string the path
	 */
	private static function generatePath($application, $directory, $file) {
		if (is_null($file)) {
			$file = $application;
			$application = "";
		}
		if (!empty($application)) {
			return "$application/$directory/$file";
		} else {
			return "$directory/$file";
		}
	}

	/**
	 * add a javascript file
	 *
	 * @param string $application application id
	 * @param string|null $file filename
	 * @param bool $prepend prepend the Script to the beginning of the list
	 * @return void
	 */
	public static function addScript($application, $file = null, $prepend = false) {
		$path = OC_Util::generatePath($application, 'js', $file);

		// core js files need separate handling
		if ($application !== 'core' && $file !== null) {
			self::addTranslations ( $application );
		}
		self::addExternalResource($application, $prepend, $path, "script");
	}

	/**
	 * add a javascript file from the vendor sub folder
	 *
	 * @param string $application application id
	 * @param string|null $file filename
	 * @param bool $prepend prepend the Script to the beginning of the list
	 * @return void
	 */
	public static function addVendorScript($application, $file = null, $prepend = false) {
		$path = OC_Util::generatePath($application, 'vendor', $file);
		self::addExternalResource($application, $prepend, $path, "script");
	}

	/**
	 * add a translation JS file
	 *
	 * @param string $application application id
	 * @param string $languageCode language code, defaults to the current language
	 * @param bool $prepend prepend the Script to the beginning of the list 
	 */
	public static function addTranslations($application, $languageCode = null, $prepend = false) {
		if (is_null($languageCode)) {
			$languageCode = \OC_L10N::findLanguage($application);
		}
		if (!empty($application)) {
			$path = "$application/l10n/$languageCode";
		} else {
			$path = "l10n/$languageCode";
		}
		self::addExternalResource($application, $prepend, $path, "script");
	}

	/**
	 * add a css file
	 *
	 * @param string $application application id
	 * @param string|null $file filename
	 * @param bool $prepend prepend the Style to the beginning of the list
	 * @return void
	 */
	public static function addStyle($application, $file = null, $prepend = false) {
		$path = OC_Util::generatePath($application, 'css', $file);
		self::addExternalResource($application, $prepend, $path, "style");
	}

	/**
	 * add a css file from the vendor sub folder
	 *
	 * @param string $application application id
	 * @param string|null $file filename
	 * @param bool $prepend prepend the Style to the beginning of the list
	 * @return void
	 */
	public static function addVendorStyle($application, $file = null, $prepend = false) {
		$path = OC_Util::generatePath($application, 'vendor', $file);
		self::addExternalResource($application, $prepend, $path, "style");
	}

	/**
	 * add an external resource css/js file
	 *
	 * @param string $application application id
	 * @param bool $prepend prepend the file to the beginning of the list
	 * @param string $path 
	 * @param string $type (script or style)
	 * @return void
	 */
	private static function addExternalResource($application, $prepend, $path, $type = "script") {

		if ($type === "style") {
			if (!in_array($path, self::$styles)) {
				if ($prepend === true) {
					array_unshift ( self::$styles, $path );
				} else {
					self::$styles[] = $path;
				}
			}
		} elseif ($type === "script") {
			if (!in_array($path, self::$scripts)) {
				if ($prepend === true) {
					array_unshift ( self::$scripts, $path );
				} else {
					self::$scripts [] = $path;
				}
			}
		}
	}

	/**
	 * Add a custom element to the header
	 * If $text is null then the element will be written as empty element.
	 * So use "" to get a closing tag.
	 * @param string $tag tag name of the element
	 * @param array $attributes array of attributes for the element
	 * @param string $text the text content for the element
	 */
	public static function addHeader($tag, $attributes, $text=null) {
		self::$headers[] = array(
			'tag' => $tag,
			'attributes' => $attributes,
			'text' => $text
		);
	}

	/**
	 * formats a timestamp in the "right" way
	 *
	 * @param int $timestamp
	 * @param bool $dateOnly option to omit time from the result
	 * @param DateTimeZone|string $timeZone where the given timestamp shall be converted to
	 * @return string timestamp
	 *
	 * @deprecated Use \OC::$server->query('DateTimeFormatter') instead
	 */
	public static function formatDate($timestamp, $dateOnly = false, $timeZone = null) {
		if ($timeZone !== null && !$timeZone instanceof \DateTimeZone) {
			$timeZone = new \DateTimeZone($timeZone);
		}

		/** @var \OC\DateTimeFormatter $formatter */
		$formatter = \OC::$server->query('DateTimeFormatter');
		if ($dateOnly) {
			return $formatter->formatDate($timestamp, 'long', $timeZone);
		}
		return $formatter->formatDateTime($timestamp, 'long', 'long', $timeZone);
	}

	/**
	 * check if the current server configuration is suitable for ownCloud
	 *
	 * @param \OCP\IConfig $config
	 * @return array arrays with error messages and hints
	 */
	public static function checkServer(\OCP\IConfig $config) {
		$l = \OC::$server->getL10N('lib');
		$errors = array();
		$CONFIG_DATADIRECTORY = $config->getSystemValue('datadirectory', OC::$SERVERROOT . '/data');

		if (!self::needUpgrade($config) && $config->getSystemValue('installed', false)) {
			// this check needs to be done every time
			$errors = self::checkDataDirectoryValidity($CONFIG_DATADIRECTORY);
		}

		// Assume that if checkServer() succeeded before in this session, then all is fine.
		if (\OC::$server->getSession()->exists('checkServer_succeeded') && \OC::$server->getSession()->get('checkServer_succeeded')) {
			return $errors;
		}

		$webServerRestart = false;
		$setup = new \OC\Setup($config, \OC::$server->getIniWrapper(), \OC::$server->getL10N('lib'),
			new \OC_Defaults(), \OC::$server->getLogger(), \OC::$server->getSecureRandom());

		$urlGenerator = \OC::$server->getURLGenerator();

		$availableDatabases = $setup->getSupportedDatabases();
		if (empty($availableDatabases)) {
			$errors[] = array(
				'error' => $l->t('No database drivers (sqlite, mysql, or postgresql) installed.'),
				'hint' => '' //TODO: sane hint
			);
			$webServerRestart = true;
		}

		// Check if server running on Windows platform
		if(OC_Util::runningOnWindows()) {
			$errors[] = [
				'error' => $l->t('Microsoft Windows Platform is not supported'),
				'hint' => $l->t('Running ownCloud Server on the Microsoft Windows platform is not supported. We suggest you ' .
					'use a Linux server in a virtual machine if you have no option for migrating the server itself. ' .
					'Find Linux packages as well as easy to deploy virtual machine images on <a href="%s">%s</a>. ' .
					'For migrating existing installations to Linux you can find some tips and a migration script ' .
					'in <a href="%s">our documentation</a>.',
					['https://owncloud.org/install/', 'owncloud.org/install/', 'https://owncloud.org/?p=8045'])
			];
		}

		// Check if config folder is writable.
		if(!OC_Helper::isReadOnlyConfigEnabled()) {
			if (!is_writable(OC::$configDir) or !is_readable(OC::$configDir)) {
				$errors[] = array(
					'error' => $l->t('Cannot write into "config" directory'),
					'hint' => $l->t('This can usually be fixed by '
						. '%sgiving the webserver write access to the config directory%s.',
						array('<a href="' . $urlGenerator->linkToDocs('admin-dir_permissions') . '" target="_blank" rel="noreferrer">', '</a>'))
				);
			}
		}

		// Check if there is a writable install folder.
		if ($config->getSystemValue('appstoreenabled', true)) {
			if (OC_App::getInstallPath() === null
				|| !is_writable(OC_App::getInstallPath())
				|| !is_readable(OC_App::getInstallPath())
			) {
				$errors[] = array(
					'error' => $l->t('Cannot write into "apps" directory'),
					'hint' => $l->t('This can usually be fixed by '
						. '%sgiving the webserver write access to the apps directory%s'
						. ' or disabling the appstore in the config file.',
						array('<a href="' . $urlGenerator->linkToDocs('admin-dir_permissions') . '" target="_blank" rel="noreferrer">', '</a>'))
				);
			}
		}
		// Create root dir.
		if ($config->getSystemValue('installed', false)) {
			if (!is_dir($CONFIG_DATADIRECTORY)) {
				$success = @mkdir($CONFIG_DATADIRECTORY);
				if ($success) {
					$errors = array_merge($errors, self::checkDataDirectoryPermissions($CONFIG_DATADIRECTORY));
				} else {
					$errors[] = array(
						'error' => $l->t('Cannot create "data" directory (%s)', array($CONFIG_DATADIRECTORY)),
						'hint' => $l->t('This can usually be fixed by '
							. '<a href="%s" target="_blank" rel="noreferrer">giving the webserver write access to the root directory</a>.',
							array($urlGenerator->linkToDocs('admin-dir_permissions')))
					);
				}
			} else if (!is_writable($CONFIG_DATADIRECTORY) or !is_readable($CONFIG_DATADIRECTORY)) {
				//common hint for all file permissions error messages
				$permissionsHint = $l->t('Permissions can usually be fixed by '
					. '%sgiving the webserver write access to the root directory%s.',
					array('<a href="' . $urlGenerator->linkToDocs('admin-dir_permissions') . '" target="_blank" rel="noreferrer">', '</a>'));
				$errors[] = array(
					'error' => 'Data directory (' . $CONFIG_DATADIRECTORY . ') not writable by ownCloud',
					'hint' => $permissionsHint
				);
			} else {
				$errors = array_merge($errors, self::checkDataDirectoryPermissions($CONFIG_DATADIRECTORY));
			}
		}

		if (!OC_Util::isSetLocaleWorking()) {
			$errors[] = array(
				'error' => $l->t('Setting locale to %s failed',
					array('en_US.UTF-8/fr_FR.UTF-8/es_ES.UTF-8/de_DE.UTF-8/ru_RU.UTF-8/'
						. 'pt_BR.UTF-8/it_IT.UTF-8/ja_JP.UTF-8/zh_CN.UTF-8')),
				'hint' => $l->t('Please install one of these locales on your system and restart your webserver.')
			);
		}

		// Contains the dependencies that should be checked against
		// classes = class_exists
		// functions = function_exists
		// defined = defined
		// ini = ini_get
		// If the dependency is not found the missing module name is shown to the EndUser
		// When adding new checks always verify that they pass on Travis as well
		// for ini settings, see https://github.com/owncloud/administration/blob/master/travis-ci/custom.ini
		$dependencies = array(
			'classes' => array(
				'ZipArchive' => 'zip',
				'DOMDocument' => 'dom',
				'XMLWriter' => 'XMLWriter',
				'XMLReader' => 'XMLReader',
			),
			'functions' => [
				'xml_parser_create' => 'libxml',
				'mb_detect_encoding' => 'mb multibyte',
				'ctype_digit' => 'ctype',
				'json_encode' => 'JSON',
				'gd_info' => 'GD',
				'gzencode' => 'zlib',
				'iconv' => 'iconv',
				'simplexml_load_string' => 'SimpleXML',
				'hash' => 'HASH Message Digest Framework',
				'curl_init' => 'cURL',
			],
			'defined' => array(
				'PDO::ATTR_DRIVER_NAME' => 'PDO'
			),
			'ini' => [
				'default_charset' => 'UTF-8',
			],
		);
		$missingDependencies = array();
		$invalidIniSettings = [];
		$moduleHint = $l->t('Please ask your server administrator to install the module.');

		/**
		 * FIXME: The dependency check does not work properly on HHVM on the moment
		 *        and prevents installation. Once HHVM is more compatible with our
		 *        approach to check for these values we should re-enable those
		 *        checks.
		 */
		$iniWrapper = \OC::$server->getIniWrapper();
		if (!self::runningOnHhvm()) {
			foreach ($dependencies['classes'] as $class => $module) {
				if (!class_exists($class)) {
					$missingDependencies[] = $module;
				}
			}
			foreach ($dependencies['functions'] as $function => $module) {
				if (!function_exists($function)) {
					$missingDependencies[] = $module;
				}
			}
			foreach ($dependencies['defined'] as $defined => $module) {
				if (!defined($defined)) {
					$missingDependencies[] = $module;
				}
			}
			foreach ($dependencies['ini'] as $setting => $expected) {
				if (is_bool($expected)) {
					if ($iniWrapper->getBool($setting) !== $expected) {
						$invalidIniSettings[] = [$setting, $expected];
					}
				}
				if (is_int($expected)) {
					if ($iniWrapper->getNumeric($setting) !== $expected) {
						$invalidIniSettings[] = [$setting, $expected];
					}
				}
				if (is_string($expected)) {
					if (strtolower($iniWrapper->getString($setting)) !== strtolower($expected)) {
						$invalidIniSettings[] = [$setting, $expected];
					}
				}
			}
		}

		foreach($missingDependencies as $missingDependency) {
			$errors[] = array(
				'error' => $l->t('PHP module %s not installed.', array($missingDependency)),
				'hint' => $moduleHint
			);
			$webServerRestart = true;
		}
		foreach($invalidIniSettings as $setting) {
			if(is_bool($setting[1])) {
				$setting[1] = ($setting[1]) ? 'on' : 'off';
			}
			$errors[] = [
				'error' => $l->t('PHP setting "%s" is not set to "%s".', [$setting[0], var_export($setting[1], true)]),
				'hint' =>  $l->t('Adjusting this setting in php.ini will make ownCloud run again')
			];
			$webServerRestart = true;
		}

		/**
		 * The mbstring.func_overload check can only be performed if the mbstring
		 * module is installed as it will return null if the checking setting is
		 * not available and thus a check on the boolean value fails.
		 *
		 * TODO: Should probably be implemented in the above generic dependency
		 *       check somehow in the long-term.
		 */
		if($iniWrapper->getBool('mbstring.func_overload') !== null &&
			$iniWrapper->getBool('mbstring.func_overload') === true) {
			$errors[] = array(
				'error' => $l->t('mbstring.func_overload is set to "%s" instead of the expected value "0"', [$iniWrapper->getString('mbstring.func_overload')]),
				'hint' => $l->t('To fix this issue set <code>mbstring.func_overload</code> to <code>0</code> in your php.ini')
			);
		}

		if(function_exists('xml_parser_create') &&
			version_compare('2.7.0', LIBXML_DOTTED_VERSION) === 1) {
			$errors[] = array(
				'error' => $l->t('libxml2 2.7.0 is at least required. Currently %s is installed.', [LIBXML_DOTTED_VERSION]),
				'hint' => $l->t('To fix this issue update your libxml2 version and restart your web server.')
			);
		}

		if (!self::isAnnotationsWorking()) {
			$errors[] = array(
				'error' => $l->t('PHP is apparently set up to strip inline doc blocks. This will make several core apps inaccessible.'),
				'hint' => $l->t('This is probably caused by a cache/accelerator such as Zend OPcache or eAccelerator.')
			);
		}

		if (!\OC::$CLI && $webServerRestart) {
			$errors[] = array(
				'error' => $l->t('PHP modules have been installed, but they are still listed as missing?'),
				'hint' => $l->t('Please ask your server administrator to restart the web server.')
			);
		}

		$errors = array_merge($errors, self::checkDatabaseVersion());

		// Cache the result of this function
		\OC::$server->getSession()->set('checkServer_succeeded', count($errors) == 0);

		return $errors;
	}

	/**
	 * Check the database version
	 *
	 * @return array errors array
	 */
	public static function checkDatabaseVersion() {
		$l = \OC::$server->getL10N('lib');
		$errors = array();
		$dbType = \OC::$server->getSystemConfig()->getValue('dbtype', 'sqlite');
		if ($dbType === 'pgsql') {
			// check PostgreSQL version
			try {
				$result = \OC_DB::executeAudited('SHOW SERVER_VERSION');
				$data = $result->fetchRow();
				if (isset($data['server_version'])) {
					$version = $data['server_version'];
					if (version_compare($version, '9.0.0', '<')) {
						$errors[] = array(
							'error' => $l->t('PostgreSQL >= 9 required'),
							'hint' => $l->t('Please upgrade your database version')
						);
					}
				}
			} catch (\Doctrine\DBAL\DBALException $e) {
				$logger = \OC::$server->getLogger();
				$logger->warning('Error occurred while checking PostgreSQL version, assuming >= 9');
				$logger->logException($e);
			}
		}
		return $errors;
	}

	/**
	 * Check for correct file permissions of data directory
	 *
	 * @param string $dataDirectory
	 * @return array arrays with error messages and hints
	 */
	public static function checkDataDirectoryPermissions($dataDirectory) {
		$l = \OC::$server->getL10N('lib');
		$errors = array();
		if (self::runningOnWindows()) {
			//TODO: permissions checks for windows hosts
		} else {
			$permissionsModHint = $l->t('Please change the permissions to 0770 so that the directory'
				. ' cannot be listed by other users.');
			$perms = substr(decoct(@fileperms($dataDirectory)), -3);
			if (substr($perms, -1) != '0') {
				chmod($dataDirectory, 0770);
				clearstatcache();
				$perms = substr(decoct(@fileperms($dataDirectory)), -3);
				if (substr($perms, 2, 1) != '0') {
					$errors[] = array(
						'error' => $l->t('Data directory (%s) is readable by other users', array($dataDirectory)),
						'hint' => $permissionsModHint
					);
				}
			}
		}
		return $errors;
	}

	/**
	 * Check that the data directory exists and is valid by
	 * checking the existence of the ".ocdata" file.
	 *
	 * @param string $dataDirectory data directory path
	 * @return array errors found
	 */
	public static function checkDataDirectoryValidity($dataDirectory) {
		$l = \OC::$server->getL10N('lib');
		$errors = [];
		if (!self::runningOnWindows() && $dataDirectory[0] !== '/') {
			$errors[] = [
				'error' => $l->t('Data directory (%s) must be an absolute path', [$dataDirectory]),
				'hint' => $l->t('Check the value of "datadirectory" in your configuration')
			];
		}
		if (!file_exists($dataDirectory . '/.ocdata')) {
			$errors[] = [
				'error' => $l->t('Data directory (%s) is invalid', [$dataDirectory]),
				'hint' => $l->t('Please check that the data directory contains a file' .
					' ".ocdata" in its root.')
			];
		}
		return $errors;
	}

	/**
	 * Check if the user is logged in, redirects to home if not. With
	 * redirect URL parameter to the request URI.
	 *
	 * @return void
	 */
	public static function checkLoggedIn() {
		// Check if we are a user
		if (!OC_User::isLoggedIn()) {
			header('Location: ' . \OC::$server->getURLGenerator()->linkToRoute(
					'core.login.showLoginForm',
					[
						'redirect_url' => \OC::$server->getRequest()->getRequestUri()
					]
				)
			);
			exit();
		}
	}

	/**
	 * Check if the user is a admin, redirects to home if not
	 *
	 * @return void
	 */
	public static function checkAdminUser() {
		OC_Util::checkLoggedIn();
		if (!OC_User::isAdminUser(OC_User::getUser())) {
			header('Location: ' . \OCP\Util::linkToAbsolute('', 'index.php'));
			exit();
		}
	}

	/**
	 * Check if it is allowed to remember login.
	 *
	 * @note Every app can set 'rememberlogin' to 'false' to disable the remember login feature
	 *
	 * @return bool
	 */
	public static function rememberLoginAllowed() {

		$apps = OC_App::getEnabledApps();

		foreach ($apps as $app) {
			$appInfo = OC_App::getAppInfo($app);
			if (isset($appInfo['rememberlogin']) && $appInfo['rememberlogin'] === 'false') {
				return false;
			}

		}
		return true;
	}

	/**
	 * Check if the user is a subadmin, redirects to home if not
	 *
	 * @return null|boolean $groups where the current user is subadmin
	 */
	public static function checkSubAdminUser() {
		OC_Util::checkLoggedIn();
		$userObject = \OC::$server->getUserSession()->getUser();
		$isSubAdmin = false;
		if($userObject !== null) {
			$isSubAdmin = \OC::$server->getGroupManager()->getSubAdmin()->isSubAdmin($userObject);
		}

		if (!$isSubAdmin) {
			header('Location: ' . \OCP\Util::linkToAbsolute('', 'index.php'));
			exit();
		}
		return true;
	}

	/**
	 * Returns the URL of the default page
	 * based on the system configuration and
	 * the apps visible for the current user
	 *
	 * @return string URL
	 */
	public static function getDefaultPageUrl() {
		$urlGenerator = \OC::$server->getURLGenerator();
		// Deny the redirect if the URL contains a @
		// This prevents unvalidated redirects like ?redirect_url=:user@domain.com
		if (isset($_REQUEST['redirect_url']) && strpos($_REQUEST['redirect_url'], '@') === false) {
			$location = $urlGenerator->getAbsoluteURL(urldecode($_REQUEST['redirect_url']));
		} else {
			$defaultPage = \OC::$server->getAppConfig()->getValue('core', 'defaultpage');
			if ($defaultPage) {
				$location = $urlGenerator->getAbsoluteURL($defaultPage);
			} else {
				$appId = 'files';
				$defaultApps = explode(',', \OCP\Config::getSystemValue('defaultapp', 'files'));
				// find the first app that is enabled for the current user
				foreach ($defaultApps as $defaultApp) {
					$defaultApp = OC_App::cleanAppId(strip_tags($defaultApp));
					if (static::getAppManager()->isEnabledForUser($defaultApp)) {
						$appId = $defaultApp;
						break;
					}
				}

				if(getenv('front_controller_active') === 'true') {
					$location = $urlGenerator->getAbsoluteURL('/apps/' . $appId . '/');
				} else {
					$location = $urlGenerator->getAbsoluteURL('/index.php/apps/' . $appId . '/');
				}
			}
		}
		return $location;
	}

	/**
	 * Redirect to the user default page
	 *
	 * @return void
	 */
	public static function redirectToDefaultPage() {
		$location = self::getDefaultPageUrl();
		header('Location: ' . $location);
		exit();
	}

	/**
	 * get an id unique for this instance
	 *
	 * @return string
	 */
	public static function getInstanceId() {
		$id = \OC::$server->getSystemConfig()->getValue('instanceid', null);
		if (is_null($id)) {
			// We need to guarantee at least one letter in instanceid so it can be used as the session_name
			$id = 'oc' . \OC::$server->getSecureRandom()->generate(10, \OCP\Security\ISecureRandom::CHAR_LOWER.\OCP\Security\ISecureRandom::CHAR_DIGITS);
			\OC::$server->getSystemConfig()->setValue('instanceid', $id);
		}
		return $id;
	}

	/**
	 * Public function to sanitize HTML
	 *
	 * This function is used to sanitize HTML and should be applied on any
	 * string or array of strings before displaying it on a web page.
	 *
	 * @param string|array $value
	 * @return string|array an array of sanitized strings or a single sanitized string, depends on the input parameter.
	 */
	public static function sanitizeHTML($value) {
		if (is_array($value)) {
			$value = array_map(function($value) {
				return self::sanitizeHTML($value);
			}, $value);
		} else {
			// Specify encoding for PHP<5.4
			$value = htmlspecialchars((string)$value, ENT_QUOTES, 'UTF-8');
		}
		return $value;
	}

	/**
	 * Public function to encode url parameters
	 *
	 * This function is used to encode path to file before output.
	 * Encoding is done according to RFC 3986 with one exception:
	 * Character '/' is preserved as is.
	 *
	 * @param string $component part of URI to encode
	 * @return string
	 */
	public static function encodePath($component) {
		$encoded = rawurlencode($component);
		$encoded = str_replace('%2F', '/', $encoded);
		return $encoded;
	}

	/**
	 * Check if the .htaccess file is working
	 * @param \OCP\IConfig $config
	 * @return bool
	 * @throws Exception
	 * @throws \OC\HintException If the test file can't get written.
	 */
	public function isHtaccessWorking(\OCP\IConfig $config) {

		if (\OC::$CLI || !$config->getSystemValue('check_for_working_htaccess', true)) {
			return true;
		}

		// php dev server does not support htaccess
		if (php_sapi_name() === 'cli-server') {
			return false;
		}

		// testdata
		$fileName = '/htaccesstest.txt';
		$testContent = 'testcontent';

		// creating a test file
		$testFile = $config->getSystemValue('datadirectory', OC::$SERVERROOT . '/data') . '/' . $fileName;

		if (file_exists($testFile)) {// already running this test, possible recursive call
			return false;
		}

		$fp = @fopen($testFile, 'w');
		if (!$fp) {
			throw new OC\HintException('Can\'t create test file to check for working .htaccess file.',
				'Make sure it is possible for the webserver to write to ' . $testFile);
		}
		fwrite($fp, $testContent);
		fclose($fp);

		// accessing the file via http
		$url = \OC::$server->getURLGenerator()->getAbsoluteURL(OC::$WEBROOT . '/data' . $fileName);
		try {
			$content = \OC::$server->getHTTPClientService()->newClient()->get($url)->getBody();
		} catch (\Exception $e) {
			$content = false;
		}

		// cleanup
		@unlink($testFile);

		/*
		 * If the content is not equal to test content our .htaccess
		 * is working as required
		 */
		return $content !== $testContent;
	}

	/**
	 * Check if the setlocal call does not work. This can happen if the right
	 * local packages are not available on the server.
	 *
	 * @return bool
	 */
	public static function isSetLocaleWorking() {
		// setlocale test is pointless on Windows
		if (OC_Util::runningOnWindows()) {
			return true;
		}

		\Patchwork\Utf8\Bootup::initLocale();
		if ('' === basename('ยง')) {
			return false;
		}
		return true;
	}

	/**
	 * Check if it's possible to get the inline annotations
	 *
	 * @return bool
	 */
	public static function isAnnotationsWorking() {
		$reflection = new \ReflectionMethod(__METHOD__);
		$docs = $reflection->getDocComment();

		return (is_string($docs) && strlen($docs) > 50);
	}

	/**
	 * Check if the PHP module fileinfo is loaded.
	 *
	 * @return bool
	 */
	public static function fileInfoLoaded() {
		return function_exists('finfo_open');
	}

	/**
	 * clear all levels of output buffering
	 *
	 * @return void
	 */
	public static function obEnd() {
		while (ob_get_level()) {
			ob_end_clean();
		}
	}

	/**
	 * Checks whether the server is running on Windows
	 *
	 * @return bool true if running on Windows, false otherwise
	 */
	public static function runningOnWindows() {
		return (substr(PHP_OS, 0, 3) === "WIN");
	}

	/**
	 * Checks whether the server is running on Mac OS X
	 *
	 * @return bool true if running on Mac OS X, false otherwise
	 */
	public static function runningOnMac() {
		return (strtoupper(substr(PHP_OS, 0, 6)) === 'DARWIN');
	}

	/**
	 * Checks whether server is running on HHVM
	 *
	 * @return bool True if running on HHVM, false otherwise
	 */
	public static function runningOnHhvm() {
		return defined('HHVM_VERSION');
	}

	/**
	 * Handles the case that there may not be a theme, then check if a "default"
	 * theme exists and take that one
	 *
	 * @return string the theme
	 */
	public static function getTheme() {
		$theme = \OC::$server->getSystemConfig()->getValue("theme", '');

		if ($theme === '') {
			if (is_dir(OC::$SERVERROOT . '/themes/default')) {
				$theme = 'default';
			}
		}

		return $theme;
	}

	/**
	 * Clear a single file from the opcode cache
	 * This is useful for writing to the config file
	 * in case the opcode cache does not re-validate files
	 * Returns true if successful, false if unsuccessful:
	 * caller should fall back on clearing the entire cache
	 * with clearOpcodeCache() if unsuccessful
	 *
	 * @param string $path the path of the file to clear from the cache
	 * @return bool true if underlying function returns true, otherwise false
	 */
	public static function deleteFromOpcodeCache($path) {
		$ret = false;
		if ($path) {
			// APC >= 3.1.1
			if (function_exists('apc_delete_file')) {
				$ret = @apc_delete_file($path);
			}
			// Zend OpCache >= 7.0.0, PHP >= 5.5.0
			if (function_exists('opcache_invalidate')) {
				$ret = opcache_invalidate($path);
			}
		}
		return $ret;
	}

	/**
	 * Clear the opcode cache if one exists
	 * This is necessary for writing to the config file
	 * in case the opcode cache does not re-validate files
	 *
	 * @return void
	 */
	public static function clearOpcodeCache() {
		// APC
		if (function_exists('apc_clear_cache')) {
			apc_clear_cache();
		}
		// Zend Opcache
		if (function_exists('accelerator_reset')) {
			accelerator_reset();
		}
		// XCache
		if (function_exists('xcache_clear_cache')) {
			if (\OC::$server->getIniWrapper()->getBool('xcache.admin.enable_auth')) {
				\OCP\Util::writeLog('core', 'XCache opcode cache will not be cleared because "xcache.admin.enable_auth" is enabled.', \OCP\Util::WARN);
			} else {
				@xcache_clear_cache(XC_TYPE_PHP, 0);
			}
		}
		// Opcache (PHP >= 5.5)
		if (function_exists('opcache_reset')) {
			opcache_reset();
		}
	}

	/**
	 * Normalize a unicode string
	 *
	 * @param string $value a not normalized string
	 * @return bool|string
	 */
	public static function normalizeUnicode($value) {
		if(Normalizer::isNormalized($value)) {
			return $value;
		}

		$normalizedValue = Normalizer::normalize($value);
		if ($normalizedValue === null || $normalizedValue === false) {
			\OC::$server->getLogger()->warning('normalizing failed for "' . $value . '"', ['app' => 'core']);
			return $value;
		}

		return $normalizedValue;
	}

	/**
	 * @param boolean|string $file
	 * @return string
	 */
	public static function basename($file) {
		$file = rtrim($file, '/');
		$t = explode('/', $file);
		return array_pop($t);
	}

	/**
	 * A human readable string is generated based on version, channel and build number
	 *
	 * @return string
	 */
	public static function getHumanVersion() {
		$version = OC_Util::getVersionString() . ' (' . OC_Util::getChannel() . ')';
		$build = OC_Util::getBuild();
		if (!empty($build) and OC_Util::getChannel() === 'daily') {
			$version .= ' Build:' . $build;
		}
		return $version;
	}

	/**
	 * Returns whether the given file name is valid
	 *
	 * @param string $file file name to check
	 * @return bool true if the file name is valid, false otherwise
	 * @deprecated use \OC\Files\View::verifyPath()
	 */
	public static function isValidFileName($file) {
		$trimmed = trim($file);
		if ($trimmed === '') {
			return false;
		}
		if (\OC\Files\Filesystem::isIgnoredDir($trimmed)) {
			return false;
		}
		foreach (str_split($trimmed) as $char) {
			if (strpos(\OCP\Constants::FILENAME_INVALID_CHARS, $char) !== false) {
				return false;
			}
		}
		return true;
	}

	/**
	 * Check whether the instance needs to perform an upgrade,
	 * either when the core version is higher or any app requires
	 * an upgrade.
	 *
	 * @param \OCP\IConfig $config
	 * @return bool whether the core or any app needs an upgrade
	 * @throws \OC\HintException When the upgrade from the given version is not allowed
	 */
	public static function needUpgrade(\OCP\IConfig $config) {
		if ($config->getSystemValue('installed', false)) {
			$installedVersion = $config->getSystemValue('version', '0.0.0');
			$currentVersion = implode('.', \OCP\Util::getVersion());
			$versionDiff = version_compare($currentVersion, $installedVersion);
			if ($versionDiff > 0) {
				return true;
			} else if ($config->getSystemValue('debug', false) && $versionDiff < 0) {
				// downgrade with debug
				$installedMajor = explode('.', $installedVersion);
				$installedMajor = $installedMajor[0] . '.' . $installedMajor[1];
				$currentMajor = explode('.', $currentVersion);
				$currentMajor = $currentMajor[0] . '.' . $currentMajor[1];
				if ($installedMajor === $currentMajor) {
					// Same major, allow downgrade for developers
					return true;
				} else {
					// downgrade attempt, throw exception
					throw new \OC\HintException('Downgrading is not supported and is likely to cause unpredictable issues (from ' . $installedVersion . ' to ' . $currentVersion . ')');
				}
			} else if ($versionDiff < 0) {
				// downgrade attempt, throw exception
				throw new \OC\HintException('Downgrading is not supported and is likely to cause unpredictable issues (from ' . $installedVersion . ' to ' . $currentVersion . ')');
			}

			// also check for upgrades for apps (independently from the user)
			$apps = \OC_App::getEnabledApps(false, true);
			$shouldUpgrade = false;
			foreach ($apps as $app) {
				if (\OC_App::shouldUpgrade($app)) {
					$shouldUpgrade = true;
					break;
				}
			}
			return $shouldUpgrade;
		} else {
			return false;
		}
	}

}