Yii2 renderPartial view in Layout - yii2

Question

I'm trying to render a view to my layout on yii2 but I get an error
PHP Notice – yii\base\ErrorException
Undefined variable: dataProvider
I create a controller category with function
public function Wdgcategory()
{
$dataProvider = new ActiveDataProvider([
'query' => Category::find(),
]);
return $this->renderPartial('wdgCategory', [
'dataProvider' => $dataProvider,
]);
}
And in my view I create a view file in category/wdgCategory.php
<?php
use yii\helpers\Html;
use yii\widgets\ListView;
?>
<?= ListView::widget([
'dataProvider' => $dataProvider,
'itemOptions' => ['class' => 'item'],
'itemView' => function ($model, $key, $index, $widget) {
return '<li>'
.Html::a(Html::encode($model->category_name),
['view', 'id' => $model->category_id])
.'<li>';
},
]) ?>
and in layout I add this code
<ul>
<?= $this->render('/category/wdgCategory') ?>
</ul>
but I get error : Undefined variable: dataProvider

Answer 1

You have defined Wdgcategory() method but you're never using it. You're just trying to render view from layout without providing necessary data ($dataProvider).
In your case you should probably create widget for this list:
class CategoriesWidget extends \yii\base\Widget {
public function run() {
$dataProvider = new ActiveDataProvider([
'query' => Category::find(),
]);
return $this->render('categories', [
'dataProvider' => $dataProvider,
]);
}
}
And use it in your layout:
<?= CategoriesWidget::widget() ?>