diff --git a/components/ActiveQuery.php b/components/ActiveQuery.php
index 5ac869d..063c80a 100644
--- a/components/ActiveQuery.php
+++ b/components/ActiveQuery.php
@@ -3,35 +3,56 @@
 
 class ActiveQuery extends \yii\db\ActiveQuery
 {
+    /**
+     * Apply condition by status
+     * @param $status
+     * @return $this
+     */
     public function status($status)
     {
         $this->andWhere(['status' => (int)$status]);
         return $this;
     }
 
+    /**
+     * Order by primary key DESC
+     * @return $this
+     */
     public function desc()
     {
         $model = $this->modelClass;
-        $this->orderBy($model::primaryKey()[0].' DESC');
+        $this->orderBy([$model::primaryKey()[0] => SORT_DESC]);
         return $this;
     }
 
+    /**
+     * Order by primary key ASC
+     * @return $this
+     */
     public function asc()
     {
         $model = $this->modelClass;
-        $this->orderBy($model::primaryKey()[0].' ASC');
+        $this->orderBy([$model::primaryKey()[0] => SORT_ASC]);
         return $this;
     }
 
+    /**
+     * Order by order_num
+     * @return $this
+     */
     public function sort()
     {
-        $this->orderBy('order_num DESC');
+        $this->orderBy(['order_num' => SORT_DESC]);
         return $this;
     }
 
+    /**
+     * Order by date
+     * @return $this
+     */
     public function sortDate()
     {
-        $this->orderBy('time DESC');
+        $this->orderBy(['time' => SORT_DESC]);
         return $this;
     }
 }
\ No newline at end of file
diff --git a/components/ActiveRecord.php b/components/ActiveRecord.php
index 76d9e40..073317e 100644
--- a/components/ActiveRecord.php
+++ b/components/ActiveRecord.php
@@ -10,6 +10,10 @@ public static function find()
         return new ActiveQuery(get_called_class());
     }
 
+    /**
+     * Formats all model errors into a single string
+     * @return string
+     */
     public function formatErrors()
     {
         $result = '';
diff --git a/components/CategoryModel.php b/components/CategoryModel.php
index 457a141..bd24d58 100644
--- a/components/CategoryModel.php
+++ b/components/CategoryModel.php
@@ -83,6 +83,10 @@ public static function find()
         return new ActiveQueryNS(get_called_class());
     }
 
+    /**
+     * Get cached tree structure of category objects
+     * @return array
+     */
     public static function tree()
     {
         return Data::cache(static::tableName().'_tree', 3600, function(){
@@ -90,6 +94,10 @@ public static function tree()
         });
     }
 
+    /**
+     * Get cached flat array of category objects
+     * @return array
+     */
     public static function cats()
     {
         return Data::cache(static::tableName().'_flat', 3600, function(){
@@ -97,6 +105,10 @@ public static function cats()
         });
     }
 
+    /**
+     * Generates tree from categories
+     * @return array
+     */
     public static function generateTree()
     {
         $collection = self::find()->with('seo')->sort()->asArray()->all();
@@ -141,6 +153,10 @@ public static function generateTree()
         return $trees;
     }
 
+    /**
+     * Generates flat array of categories
+     * @return array
+     */
     public static function generateFlat()
     {
         $collection = self::find()->with('seo')->sort()->asArray()->all();
diff --git a/components/Controller.php b/components/Controller.php
index dd389b1..102c049 100644
--- a/components/Controller.php
+++ b/components/Controller.php
@@ -12,6 +12,13 @@ class Controller extends \yii\web\Controller
     public $rootActions = [];
     public $error = null;
 
+    /**
+     * Check authentication, and root rights for actions
+     * @param \yii\base\Action $action
+     * @return bool
+     * @throws \yii\web\BadRequestHttpException
+     * @throws \yii\web\ForbiddenHttpException
+     */
     public function beforeAction($action)
     {
         if(!parent::beforeAction($action))
@@ -34,6 +41,11 @@ public function beforeAction($action)
         }
     }
 
+    /**
+     * Write in sessions alert messages
+     * @param string $type error or success
+     * @param string $message alert body
+     */
     public function flash($type, $message)
     {
         Yii::$app->getSession()->setFlash($type=='error'?'danger':$type, $message);
@@ -44,16 +56,31 @@ public function back()
         return $this->redirect(Yii::$app->request->referrer);
     }
 
+    /**
+     * Set return url for module in sessions
+     * @param mixed $url if not set, returnUrl will be current page
+     */
     public function setReturnUrl($url = null)
     {
         Yii::$app->getSession()->set($this->module->id.'_return', $url ? Url::to($url) : Url::current());
     }
 
+    /**
+     * Get return url for module from session
+     * @param mixed $defaultUrl if return url not found in sessions
+     * @return mixed
+     */
     public function getReturnUrl($defaultUrl = null)
     {
         return Yii::$app->getSession()->get($this->module->id.'_return', $defaultUrl ? Url::to($defaultUrl) : Url::to('/admin/'.$this->module->id));
     }
 
+    /**
+     * Formats response depending on request type (ajax or not)
+     * @param string $success
+     * @param bool $back go back or refresh
+     * @return mixed $result array if request is ajax.
+     */
     public function formatResponse($success = '', $back = true)
     {
         if(Yii::$app->request->isAjax){