gistfile1.js

<?php

use yii\web\View;
use yii\bootstrap\Progress;
use kartik\helpers\Html;
use kartik\grid\GridView;
use app\models\SampleTask;
use kartik\datecontrol\DateControl;
use kartik\widgets\ActiveForm;
use kartik\builder\Form;
use kartik\widgets\DatePicker;
use kartik\widgets\FileInput;
use kartik\widgets\Select2;
use kartik\widgets\SwitchInput;
use yii\helpers\ArrayHelper;
use app\models\search\UserSearch;

?>

<?php

    $form = ActiveForm::begin([
            'validateOnSubmit' => true,
            'type' => ActiveForm::TYPE_VERTICAL,
            'options' => ['class' => 'main-task-form']
        ]);

    echo Form::widget([
            'model' => $modelData,
            'form' => $form,
            'columns' => 2,
            'attributes' => [
                'closeDate' => [
                        'type'=> 'widget',
                        'widgetClass'=> DatePicker::className(),
                        'options'=>[
                            'type' => DatePicker::TYPE_COMPONENT_APPEND,
                            'pluginOptions' => [
                                'autoclose' => true,
                                'language' => 'es',
                                'format' => 'dd-mm-yyyy',
                                'todayBtn' => 'linked',
                            ],
                        ],
                    ],
                'descriptionClose' => [
                    'type'=>'textarea', 
                    'options' => [
                        'rows' => 3,
                    ],
                ],
            ],
        ]);
?>
            

<?php ActiveForm::end() ?>
<!-- Form Ends Here -->


<!-- Submit Button Outside Form -->
<?= Html::button('Completar Tarea', ['class' => 'btn btn-primary btn-task-form']) ?>