- Кнопка удаления файла кастомизирована;

common/modules/analyticsSchool/views/lesson-admin/_files.php

@@ -25,7 +25,16 @@ echo GridView::widget([
 
         [
             'class' => 'yii\grid\ActionColumn',
-            'template' => '{delete}'
+            'template' => '{delete}',
+            'buttons' => [
+                'delete' => function($url, $model) {
+                        return Html::tag(
+                            'a',
+                            Html::tag('span', '', ['class' => 'glyphicon glyphicon-trash']),
+                            ["href" => Yii::$app->urlManager->createUrl(['/analyticsSchool/lesson-admin/deletefile', 'id' => $model->id])]
+                        );
+                    }
+            ]
         ],
     ],
 ]);