public function actionCreate()
    {
        $model = new Product();
        $categories = Category::find()->all();
        $selectCategories = [];

        if ($post = Yii::$app->request->post()) {
            $model->templateFields = ArrayHelper::getValue($post, 'templateFields');
            $selectCategories = ArrayHelper::getValue($post, 'Product.selectCategories');
        }
        $isOk = true;
        $transaction = Product::getDb()->beginTransaction();
        if ($model->load($post) && $isOk &= $model->save()) {
            if (is_array($selectCategories)) {
                $id = $model->id;
                ProductCategory::deleteAll(['product_id' => $id]);
                foreach ($selectCategories as $categoryId) {
                    $productCategory = new ProductCategory();
                    $productCategory->product_id = $id;
                    $productCategory->category_id = $categoryId;
                    $isOk &= $productCategory->save();
                }
            }
            if (!empty($model->templateFields)) {
                foreach ($model->templateFields as $position => $fields) {
                    foreach ($fields as $name => $value) {
                        $file = UploadedFile::getInstanceByName('imageFiles['.$position.']['.$name.']');
                        if ($file) {
                            $fileName = uniqid().'.'.$file->extension;
                            $file->saveAs(\Yii::getAlias('@webroot/uploads/'.$fileName));
                            $model->templateFields[$position][$name] = $fileName;
                        }
                    }
                }
                $isOk &= $model->save(false);
            }
            if ($isOk) {
                $transaction->commit();
            } else {
                $transaction->rollBack();
            }

            return $this->redirect(['index']);
        } else {
            return $this->render('create', [
                'model' => $model,
                'categories' => $categories,
            ]);
        }
    }