diff --git a/GalleryBehavior.php b/GalleryBehavior.php
index 54e52e7..6cfeb08 100644
--- a/GalleryBehavior.php
+++ b/GalleryBehavior.php
@@ -4,6 +4,7 @@
 
 use Imagine\Image\Box;
 use Imagine\Image\ImageInterface;
+use Yii;
 use yii\base\Behavior;
 use yii\base\Exception;
 use yii\db\ActiveRecord;
@@ -17,6 +18,7 @@
  * @author Bogdan Savluk <savluk.bogdan@gmail.com>
  *
  * @property string $galleryId
+ * @property string $temporaryId
  */
 class GalleryBehavior extends Behavior
 {
@@ -25,6 +27,11 @@ class GalleryBehavior extends Behavior
      * @var string
      */
     public $pkGlue = '_';
+    /**
+     * The prefix of string for temporary id for new models
+     * @var string
+     */
+    public $temporaryPrefix = 'temp';
     /**
      * @var string Type name assigned to model in image attachment action
      * @see     GalleryManagerAction::$types
@@ -133,6 +140,8 @@ public function events()
             ActiveRecord::EVENT_BEFORE_DELETE => 'beforeDelete',
             ActiveRecord::EVENT_AFTER_UPDATE => 'afterUpdate',
             ActiveRecord::EVENT_AFTER_FIND => 'afterFind',
+            ActiveRecord::EVENT_BEFORE_INSERT => 'afterFind',
+            ActiveRecord::EVENT_AFTER_INSERT => 'afterInsert',
         ];
     }
 
@@ -142,8 +151,7 @@ public function beforeDelete()
         foreach ($images as $image) {
             $this->deleteImage($image->id);
         }
-        $dirPath = $this->directory . '/' . $this->getGalleryId();
-        @rmdir($dirPath);
+        $this->removeDirectory($this->getDirectoryPath());
     }
 
     public function afterFind()
@@ -154,10 +162,37 @@ public function afterFind()
     public function afterUpdate()
     {
         $galleryId = $this->getGalleryId();
-        if ($this->_galleryId != $galleryId) {
+        if ($this->_galleryId && ($this->_galleryId != $galleryId)) {
             $dirPath1 = $this->directory . '/' . $this->_galleryId;
             $dirPath2 = $this->directory . '/' . $galleryId;
-            rename($dirPath1, $dirPath2);
+            if (is_dir($dirPath1)) {
+                rename($dirPath1, $dirPath2);
+            }
+        }
+    }
+
+    /**
+     * Move dir and change id to actual
+     * @throws Exception
+     * @throws \yii\db\Exception
+     */
+    public function afterInsert()
+    {
+        $galleryId = $this->getGalleryId();
+        if ($this->_galleryId && ($this->_galleryId != $galleryId)) {
+
+            \Yii::$app->db->createCommand()
+                ->update(
+                    $this->tableName,
+                    ['ownerId' => $galleryId],
+                    ['ownerId' => $this->_galleryId, 'type' => $this->type]
+                )->execute();
+
+            $dirPath1 = $this->directory . '/' . $this->_galleryId;
+            $dirPath2 = $this->directory . '/' . $galleryId;
+            if (is_dir($dirPath1)) {
+                rename($dirPath1, $dirPath2);
+            }
         }
     }
 
@@ -165,6 +200,7 @@ public function afterUpdate()
 
     /**
      * @return GalleryImage[]
+     * @throws Exception
      */
     public function getImages()
     {
@@ -223,6 +259,39 @@ public function getFilePath($imageId, $version = 'original')
         return $this->directory . '/' . $this->getFileName($imageId, $version);
     }
 
+    public function getDirectoryPath()
+    {
+        return $this->directory . '/' . $this->getGalleryId();
+    }
+
+    /**
+     * Generate a temporary id for new models
+     * @return string
+     */
+    public function getTemporaryId()
+    {
+        return $this->temporaryPrefix . Yii::$app->session->getId();
+    }
+
+    /**
+     * Get Gallery Id
+     *
+     * @return mixed as string or integer
+     * @throws Exception
+     */
+    public function getGalleryId()
+    {
+        $pk = $this->owner->getPrimaryKey();
+        if ($pk === null) {
+            $pk = $this->temporaryId;
+        }
+        if (is_array($pk)) {
+            return implode($this->pkGlue, $pk);
+        } else {
+            return $pk;
+        }
+    }
+
     /**
      * Replace existing image by specified file
      *
@@ -252,31 +321,48 @@ public function replaceImage($imageId, $path)
         }
     }
 
+    /**
+     * Remove single image file
+     * @param $fileName
+     * @return bool
+     */
     private function removeFile($fileName)
     {
-        return FileHelper::unlink($fileName);
+        try {
+            return FileHelper::unlink($fileName);
+        } catch (\yii\base\ErrorException $exception) {
+            return false;
+        }
     }
 
     /**
-     * Get Gallery Id
-     *
-     * @return mixed as string or integer
-     * @throws Exception
+     * Remove a folders for gallery files
+     * @param $filePath string the filename of image
+     * @return bool
      */
-    public function getGalleryId()
+    private function removeDirectory($filePath)
     {
-        $pk = $this->owner->getPrimaryKey();
-        if (is_array($pk)) {
-            return implode($this->pkGlue, $pk);
-        } else {
-            return $pk;
+        try {
+            FileHelper::removeDirectory(dirname($filePath));
+        } catch (\yii\base\ErrorException $exception) {
+            return false;
         }
-    }
 
+        return true;
+    }
 
+    /**
+     * Create a folders for gallery files
+     * @param $filePath string the filename of image
+     * @return bool
+     */
     private function createFolders($filePath)
     {
-        return FileHelper::createDirectory(FileHelper::normalizePath(dirname($filePath)), 0777);
+        try {
+            return FileHelper::createDirectory(FileHelper::normalizePath(dirname($filePath)), 0777);
+        } catch (\yii\base\Exception $exception) {
+            return false;
+        }
     }
 
     /////////////////////////////// ========== Public Actions ============ ///////////////////////////
@@ -287,10 +373,7 @@ public function deleteImage($imageId)
             $this->removeFile($filePath);
         }
         $filePath = $this->getFilePath($imageId, 'original');
-        $parts = explode('/', $filePath);
-        $parts = array_slice($parts, 0, count($parts) - 1);
-        $dirPath = implode('/', $parts);
-        @rmdir($dirPath);
+        $this->removeDirectory($filePath);
 
         $db = \Yii::$app->db;
         $db->createCommand()
@@ -314,6 +397,35 @@ function ($image) use (&$removed) {
                 }
             );
         }
+        if (is_null($this->_images)) {
+            $this->removeDirectory($this->getDirectoryPath());
+        }
+    }
+
+    /**
+     * Remove images for expired session
+     * actions is a {'apiRoute'}?action=deleteOrphan&type={'type'}&behaviorName={'behaviorName'}
+     * @throws \yii\base\ErrorException
+     * @throws \yii\db\Exception
+     */
+    public function deleteOrphanImages()
+    {
+        $toDelete = \Yii::$app->db->createCommand(
+            'SELECT DISTINCT `ownerId` FROM ' . $this->tableName . ' WHERE `ownerId` LIKE :ownerId AND `type` = :type',
+            [':ownerId' => $this->temporaryPrefix . '%', ':type' => $this->type]
+        )->queryColumn();
+
+        foreach ($toDelete as $item) {
+            \Yii::$app->db->createCommand()
+                ->delete(
+                    $this->tableName,
+                    [
+                        'type' => $this->type,
+                        'ownerId' => $item,
+                    ]
+                )->execute();
+            FileHelper::removeDirectory($this->directory . '/' . $item);
+        }
     }
 
     public function addImage($fileName)
@@ -383,6 +495,8 @@ public function arrange($order)
      * @param array $imagesData
      *
      * @return GalleryImage[]
+     * @throws Exception
+     * @throws \yii\db\Exception
      */
     public function updateImagesData($imagesData)
     {
@@ -432,6 +546,7 @@ public function updateImagesData($imagesData)
      * Should be called in migration on every model after changes in versions configuration
      *
      * @param string|null $oldExtension
+     * @throws Exception
      */
     public function updateImages($oldExtension = null)
     {
diff --git a/GalleryManagerAction.php b/GalleryManagerAction.php
index fc7e3c9..80418ca 100644
--- a/GalleryManagerAction.php
+++ b/GalleryManagerAction.php
@@ -8,6 +8,7 @@
 use yii\db\ActiveRecord;
 use yii\helpers\Json;
 use yii\web\HttpException;
+use yii\web\NotFoundHttpException;
 use yii\web\UploadedFile;
 
 /**
@@ -28,10 +29,17 @@ class GalleryManagerAction extends Action
      */
     public $pkGlue = '_';
 
+    /**
+     * The prefix of string for temporary id for new models
+     * @var string
+     */
+    public $temporaryPrefix = 'temp';
+
     /**
      * $types to be defined at Controller::actions()
      * @var array Mapping between types and model class names
-     * @example 'post'=>'common\models\Post'
+     * @example 'post' => 'common\models\Post'
+     * @example 'post' => ['class' => common\models\Post::class]
      * @see     GalleryManagerAction::run
      */
     public $types = [];
@@ -52,30 +60,35 @@ public function run($action)
         $this->type = Yii::$app->request->get('type');
         $this->behaviorName = Yii::$app->request->get('behaviorName');
         $this->galleryId = Yii::$app->request->get('galleryId');
-        $pkNames = call_user_func([$this->types[$this->type], 'primaryKey']);
-        $pkValues = explode($this->pkGlue, $this->galleryId);
-
-        $pk = array_combine($pkNames, $pkValues);
 
-        $this->owner = call_user_func([$this->types[$this->type], 'findOne'], $pk);
+        if (!array_key_exists($this->type, $this->types)) {
+            throw new HttpException(400, 'Type does not exists');
+        }
+        $this->owner = Yii::createObject($this->types[$this->type]);
+        if ($this->galleryId && substr_compare($this->galleryId, $this->temporaryPrefix, 0, strlen($this->temporaryPrefix)) !== 0) {
+            $pkNames = $this->owner->primaryKey();
+            $pkValues = explode($this->pkGlue, $this->galleryId);
+            $pk = array_combine($pkNames, $pkValues);
+            $this->owner = $this->owner::findOne($pk);
+            if (!$this->owner) {
+                throw new NotFoundHttpException();
+            }
+        }
         $this->behavior = $this->owner->getBehavior($this->behaviorName);
 
         switch ($action) {
             case 'delete':
                 return $this->actionDelete(Yii::$app->request->post('id'));
-                break;
             case 'ajaxUpload':
                 return $this->actionAjaxUpload();
-                break;
             case 'changeData':
                 return $this->actionChangeData(Yii::$app->request->post('photo'));
-                break;
             case 'order':
                 return $this->actionOrder(Yii::$app->request->post('order'));
-                break;
+            case 'deleteOrphan':
+                return $this->actionDeleteOrphan();
             default:
-                throw new HttpException(400, 'Action do not exists');
-                break;
+                throw new HttpException(400, 'Action does not exists');
         }
     }
 
@@ -85,7 +98,6 @@ public function run($action)
      *
      * @param $ids
      *
-     * @throws HttpException
      * @return string
      */
     protected function actionDelete($ids)
@@ -96,12 +108,27 @@ protected function actionDelete($ids)
         return 'OK';
     }
 
+    /**
+     * Removes orphan images for this gallery
+     * On success returns 'OK'
+     *
+     * @return string
+     * @throws \yii\base\ErrorException
+     * @throws \yii\db\Exception
+     */
+    protected function actionDeleteOrphan()
+    {
+
+        $this->behavior->deleteOrphanImages();
+
+        return 'OK';
+    }
+
     /**
      * Method to handle file upload thought XHR2
      * On success returns JSON object with image info.
      *
      * @return string
-     * @throws HttpException
      */
     public function actionAjaxUpload()
     {
@@ -119,8 +146,8 @@ public function actionAjaxUpload()
             array(
                 'id' => $image->id,
                 'rank' => $image->rank,
-                'name' => (string)$image->name,
-                'description' => (string)$image->description,
+                'name' => (string) $image->name,
+                'description' => (string) $image->description,
                 'preview' => $image->getUrl('preview'),
             )
         );
@@ -142,7 +169,6 @@ public function actionOrder($order)
         $res = $this->behavior->arrange($order);
 
         return Json::encode($res);
-
     }
 
     /**
@@ -151,8 +177,10 @@ public function actionOrder($order)
      *
      * @param $imagesData
      *
-     * @throws HttpException
      * @return string
+     * @throws HttpException
+     * @throws \yii\base\Exception
+     * @throws \yii\db\Exception
      */
     public function actionChangeData($imagesData)
     {
@@ -165,8 +193,8 @@ public function actionChangeData($imagesData)
             $resp[] = array(
                 'id' => $model->id,
                 'rank' => $model->rank,
-                'name' => (string)$model->name,
-                'description' => (string)$model->description,
+                'name' => (string) $model->name,
+                'description' => (string) $model->description,
                 'preview' => $model->getUrl('preview'),
             );
         }