diff --git a/appinfo/application.php b/appinfo/application.php
index 7d2dc9da..a36f7855 100644
--- a/appinfo/application.php
+++ b/appinfo/application.php
@@ -66,14 +66,16 @@ class Application extends App {
 		$container->registerService('Logger', function($c) {
 			return $c->query('ServerContainer')->getLogger();
 		});
-        $container->registerService('CoreConfig', function($c) {
-            return $c->query('ServerContainer')->getConfig();
-        });
-        $container->registerService('L10N', function($c) {
-            return $c->query('ServerContainer')->getL10N($c->query('AppName'));
-        });
-        $container->registerService('UserId', function($c) {
-            return $c->query('ServerContainer')->getUserSession()->getUser()->getUID();
-        });
+		$container->registerService('CoreConfig', function($c) {
+			return $c->query('ServerContainer')->getConfig();
+		});
+		$container->registerService('L10N', function($c) {
+			return $c->query('ServerContainer')->getL10N($c->query('AppName'));
+		});
+		$container->registerService('UserId', function($c) {
+			$user = $c->query('ServerContainer')->getUserSession()->getUser();
+			$uid = is_null($user) ? '' : $user->getUID();
+			return $uid;
+		});
 	}
 }
diff --git a/controller/documentcontroller.php b/controller/documentcontroller.php
index c1137b7d..c68a843d 100644
--- a/controller/documentcontroller.php
+++ b/controller/documentcontroller.php
@@ -168,7 +168,8 @@ class DocumentController extends Controller{
 			} else {
 				$documents[$key] = $document;
 			}
-			$documents[$key]['icon'] = preg_replace('/\.png$/', '.svg', \OC_Helper::mimetypeIcon($document['mimetype']));
+			$documents[$key]['icon'] = preg_replace('/\.png$/', '.svg', \OCP\Template::mimetype_icon($document['mimetype']));
+			$documents[$key]['hasPreview'] = \OC::$server->getPreviewManager()->isMimeSupported($document['mimetype']);
 			$fileIds[] = $document['fileid'];
 		}
 
diff --git a/js/documents.js b/js/documents.js
index 2eabb8d7..0bcf1943 100644
--- a/js/documents.js
+++ b/js/documents.js
@@ -61,7 +61,7 @@ $.widget('oc.documentGrid', {
 		previewURL = OC.generateUrl('/core/preview.png?') + $.param(urlSpec);
 		previewURL = previewURL.replace('(', '%28').replace(')', '%29');
 		
-		if ( $('#previews_enabled').length ) {
+		if ( $('#previews_enabled').length && document.hasPreview) {
 			var img = new Image();
 			img.onload = function(){
 				var ready = function (node){
diff --git a/lib/db.php b/lib/db.php
index 918ec7b8..53935830 100644
--- a/lib/db.php
+++ b/lib/db.php
@@ -57,7 +57,7 @@ abstract class Db {
 		}
 		
 		$result = $this->execute($this->loadStatement, $value);
-		$data = $result->fetchRow();
+		$data = $result->fetch();
 		if (!is_array($data)){
 			$data = array();
 		}
@@ -194,7 +194,7 @@ abstract class Db {
 	 * @return mixed (array/false)
 	 */
 	protected function execute($statement, $args = null){
-		$query = \OCP\DB::prepare($statement);
+		$query = \OC::$server->getDatabaseConnection()->prepare($statement);
 		
 		if (!is_null($args)){
 			$result = $query->execute($args);
@@ -204,7 +204,7 @@ abstract class Db {
 			$result = $query->execute();
 		}
 		
-		return $result;
+		return $result ? $query : false;
 	}
 	
 	public function __call($name, $arguments){
diff --git a/lib/db/op.php b/lib/db/op.php
index 50449398..b8a8ff03 100644
--- a/lib/db/op.php
+++ b/lib/db/op.php
@@ -41,18 +41,14 @@ class Op extends \OCA\Documents\Db {
 	 * @returns "" when there are no Ops, or the seq of the last Op
 	 */
 	public function getHeadSeq($esId){
-		$query = \OCP\DB::prepare('
+		$query = \OC::$server->getDatabaseConnection()->prepare('
 			SELECT `seq`
 			FROM ' . $this->tableName . '
 			WHERE `es_id`=?
 			ORDER BY `seq` DESC
 			', 1);
-		$result = $query->execute(array(
-				$esId
-			))
-			->fetchOne()	
-		;
-		return !$result ? "" : $result;
+		$result = $query->execute([$esId]);
+		return !$result ? "" : $query->fetchColumn();
 	}
 	
 	public function getOpsAfterJson($esId, $seq){
@@ -75,7 +71,7 @@ class Op extends \OCA\Documents\Db {
 		if ($seq == ""){
 			$seq = -1;
 		}
-		$query = \OCP\DB::prepare('
+		$query = \OC::$server->getDatabaseConnection()->prepare('
 			SELECT `opspec`
 			FROM ' . self::DB_TABLE . '
 			WHERE `es_id`=?
@@ -83,7 +79,7 @@ class Op extends \OCA\Documents\Db {
 			ORDER BY `seq` ASC
 			');
 		$result = $query->execute(array($esId, $seq));
-		return $result->fetchAll();
+		return $query->fetchAll();
 	}
 	
 	public function addMember($esId, $memberId, $fullName, $userId, $color, $imageUrl){
diff --git a/lib/db/session.php b/lib/db/session.php
index b8de3c1c..cbfe0cb8 100644
--- a/lib/db/session.php
+++ b/lib/db/session.php
@@ -93,7 +93,7 @@ class Session extends \OCA\Documents\Db {
 		$sessionData['member_id'] = (string) $member->getLastInsertId();
 		
 		// Do we have OC_Avatar in out disposal?
-		if (\OC_Config::getValue('enable_avatars', true) !== true){
+		if (\OC::$server->getConfig()->getSystemValue('enable_avatars', true) !== true){
 			$imageUrl = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAAAAACH5BAAAAAAALAAAAAABAAEAAAICTAEAOw==';
 		} else {
 			$imageUrl = $uid;
@@ -198,7 +198,7 @@ class Session extends \OCA\Documents\Db {
 			]
 		);
 
-		$info = $result->fetchRow();
+		$info = $result->fetch();
 		if (!is_array($info)){
 			$info = array();
 		}
diff --git a/public.php b/public.php
index bb3c9971..b3b84eee 100644
--- a/public.php
+++ b/public.php
@@ -15,7 +15,7 @@ namespace OCA\Documents;
 
 \OCP\JSON::checkAppEnabled('documents');
 
-if (\OC_Appconfig::getValue('core', 'shareapi_allow_links', 'yes') !== 'yes') {
+if (\OC::$server->getConfig()->getAppValue('core', 'shareapi_allow_links', 'yes') !== 'yes') {
 	header('HTTP/1.0 404 Not Found');
 	$tmpl = new OCP\Template('', '404', 'guest');
 	$tmpl->printPage();
diff --git a/templates/documents.php b/templates/documents.php
index 20e0bef4..df5faf24 100644
--- a/templates/documents.php
+++ b/templates/documents.php
@@ -16,7 +16,7 @@ script('files', 'jquery.fileupload');
 				<form data-upload-id="1"
 					  id="data-upload-form"
 					  class="file_upload_form"
-					  action="<?php print_unescaped(OCP\Util::linkTo('files', 'ajax/upload.php')); ?>"
+					  action="<?php print_unescaped(link_to('files', 'ajax/upload.php')); ?>"
 					  method="post"
 					  enctype="multipart/form-data"
 					  target="file_upload_target_1">