Yarik / artbox1

  <?php
      
      use common\models\ProductToProject;
      use common\models\Project;
      use common\modules\product\models\Product;
      use yii\helpers\Html;
      use yii\web\View;
      use yii\widgets\ActiveForm;
      
      /**
       * @var View             $this
       * @var Project          $project
       * @var Product[]        $products
       * @var ProductToProject $model
       * @var array            $variants
       */

      if($model->isNewRecord) {
          $this->title = \Yii::t('app', 'Create product to project');
      } else {
          $this->title = \Yii::t('app', 'Update product to project');
      }

      $this->params[ 'breadcrumbs' ][] = [

          'label' => \Yii::t('app', 'Project'),
          'url'   => [
              'index',
          ],
      ];
      $this->params[ 'breadcrumbs' ][] = [
          'label' => \Yii::t('app', 'Products to project' . ': ' . $project->lang->title),

          'url'   => [
              'product',
              'id' => $project->project_id,
          ],
      ];
      $this->params[ 'breadcrumbs' ][] = $this->title;
  ?>

      <div class="articles-create">
          <h1><?= Html::encode($this->title) ?></h1>
          <?php
              $form = ActiveForm::begin();
              echo $form->field($model, 'product_id')
                        ->dropDownList($products, [ 'prompt' => \Yii::t('app', 'Выберите коллекцию') ]);
          ?>
          <div class="<?php echo( !empty( $variants ) ? '' : 'hidden' ); ?> product_variant_container">
              <?php
                  echo $form->field($model, 'product_variant_id')
                            ->dropDownList($variants, [ 'prompt' => \Yii::t('app', 'Выберите товар') ]);
              ?>
          </div>

          <?php

              echo Html::submitInput(( $model->isNewRecord ? \Yii::t('app', 'Добавить') : \Yii::t('app', 'Обновить') ), [ 'class' => 'btn btn-success' ]);
              $form::end();

          ?>
      </div>

  <?php

      $this->registerJs("

            $(document).on(

                  'change', '#producttoproject-product_id', function(e)
                  {
                      var value = parseInt($(this).val());
                      var dropDown = $('#producttoproject-product_variant_id');
                      var container = $(dropDown).parents('.product_variant_container');

                      $(dropDown).find('option[value!=\"\"]').remove();

                      $(container).addClass('hidden');
                      if(value)
                      {
                          $.get(
                              '/admin/project/get-variants?product_id=' + value, function(data)
                              {
                                  if(data.length > 0)
                                  {
                                      $.each(
                                          data, function(key, value)
                                          {

                                              $(dropDown)

                                              .append('<option value=\"' + value.product_variant_id + '\">' + value.lang.name + '</option>');

                                          }
                                      );

                                      $(container).removeClass('hidden');
                                  }
                              }
                          );
                      }
                  }
              );

  ");
  ?>