Refactored the code for #3154

framework/CHANGELOG.md

@@ -24,6 +24,7 @@ Yii Framework 2 Change Log
 - Enh #3103: debugger panel is now not displayed when printing a page (githubjeka)
 - Enh #3108: Added `yii\debug\Module::enableDebugLogs` to disable logging debug logs by default (qiangxue)
 - Enh #3132: `yii\rbac\PhpManager` now supports more compact data file format (qiangxue)
+- Enh #3154: Added validation error display for `GridView` filters (ivan-kolmychek)
 - Enh: Added support for using sub-queries when building a DB query with `IN` condition (qiangxue)
 - Enh: Supported adding a new response formatter without the need to reconfigure existing formatters (qiangxue)
 - Enh: Added `yii\web\UrlManager::addRules()` to simplify adding new URL rules (qiangxue)

framework/grid/GridView.php

@@ -181,7 +181,7 @@ class GridView extends BaseListView
      * The following tokens will be replaced with the corresponding section contents:
      *
      * - `{summary}`: the summary section. See [[renderSummary()]].
-     * - `{error}`: the filter model errors. See [[renderErrors()]].
+     * - `{errors}`: the filter model errors. See [[renderErrors()]].
      * - `{items}`: the list items. See [[renderItems()]].
      * - `{sorter}`: the sorter. See [[renderSorter()]].
      * - `{pager}`: the pager. See [[renderPager()]].
@@ -227,22 +227,17 @@ class GridView extends BaseListView
     }
 
     /**
-     * @inheritdoc
+     * Renders validator errors of filter model.
+     * @return string the rendering result.
      */
     public function renderErrors()
     {
-        if ($this->filterModel instanceof Model && $this->filterModel->hasErrors()) 
-        {
-            $errorsList = [];
-            foreach($this->filterModel->errors as $attribute => $errors) 
-            {
-                    $errorsList = ArrayHelper::merge($errorsList, $errors); 
-            }
-            return Html::tag('div', Html::ul($errorsList, ['class' => 'help-block']), ['class' => 'has-error']);
-        }
-        
+        if ($this->filterModel instanceof Model && $this->filterModel->hasErrors()) {
+            return Html::tag('div', Html::ul($this->filterModel->getFirstErrors(), ['class' => 'help-block']), ['class' => 'has-error']);
+        } else {
             return '';
         }
+    }
 
     public function renderSection($name)
     {