How to save value in depdrop after page reload?

Question

Yii

Hello.
There is a filter on the page, two selects dependent on each other (Select2 and DepDrop). If you select from the filter, everything works well, the table is filtered. And if, for example, we go to the details of a record and go back or just refresh the page, then the second select (DepDrop) is reset, it just becomes disabled and shows the placeholder, but the records are displayed correctly, that is, the ones that were filtered. How to save the selection of the second select? So that after refreshing the page, the selected value remains?
view

<div class="col-lg-6 col-md-6">
    <?php echo $form->field($model, 'Cat')
    ->label(false)
    ->widget(Select2::class, [
        'data'=> Orders::getCat(),
        'value' => '',
        'options' => [
            'id'=>'cat_id',
            'placeholder' => 'Cat...',
        ],
        'pluginOptions' => [
            'allowClear' => true,
        ],
    ]) ?>
</div>

<div class="col-lg-6 col-md-6">
    <?php
    echo $form->field($model, 'sub')
        ->widget(DepDrop::class, [
            'type' => DepDrop::TYPE_SELECT2,
            'select2Options' => [
                'pluginOptions'=>['allowClear'=>true,]
            ],
            'options'=>[
                'id'=>'sub_id'
            ],
            'pluginOptions'=>[
                'depends'=>['typ-id'],
                'placeholder'=>'Sub...',
                'url'=>Url::to(['orders/subcat']),
            ],
        ])->label(false);
    ?>
</div>

controller

public function actionSubcat() {
    $out = [];

    if (isset($_POST['depdrop_parents'])) {
        $parents = $_POST['depdrop_parents'];

        if ($parents !== null) {
            $cat_id = $parents[0];
            $listCat = Orders::findCatId($cat_id);
            $out[] = ['id' => $value['id'], 'name' => $value['name']];

            echo Json::encode(['output'=>$out, 'selected'=>'']);
            return;
        }
    }
    echo Json::encode(['output'=>'', 'selected'=>'']);
}

Answer 1

Try to specify for the second select

'pluginOptions' => [
                'depends'=>['typ-id'],
                'placeholder'=>'Sub...',
                'initialize' => true,
                'initDepends'=>['Cat'],
                'url'=>Url::to(['orders/subcat']),
            ],

Example link: demos.krajee.com/widget-details/depdrop#advanced-usage