addForm example

    $types = [];
    // Only use block types the user has access to.     foreach ($this->blockContentTypeStorage->loadMultiple() as $type) {
      $access = $this->entityTypeManager()->getAccessControlHandler('block_content')->createAccess($type->id(), NULL, [], TRUE);
      if ($access->isAllowed()) {
        $types[$type->id()] = $type;
      }
    }
    uasort($types, [$this->blockContentTypeStorage->getEntityType()->getClass(), 'sort']);
    if ($types && count($types) == 1) {
      $type = reset($types);
      return $this->addForm($type, $request);
    }
    if (count($types) === 0) {
      return [
        '#markup' => $this->t('You have not created any block types yet. Go to the <a href=":url">block type creation page</a> to add a new block type.', [
          ':url' => Url::fromRoute('block_content.type_add')->toString(),
        ]),
      ];
    }

    return ['#theme' => 'block_content_add_list', '#content' => $types];
  }

  

use Shopware\Models\Config\Element;

class Shopware_Plugins_Frontend_TagCloud_Bootstrap extends Shopware_Components_Plugin_Bootstrap
{
    public function install()
    {
        $this->subscribeEvent(
            'Enlight_Controller_Action_PostDispatch',
            'onPostDispatch'
        );

        $this->addForm();
        $this->translateForm();

        return true;
    }

    /** * @return array */
    public function getInfo()
    {
        return [