linkTemplates example

    }
    if ($storages_to_delete) {
      \Drupal::entityTypeManager()->getStorage('field_storage_config')->delete($storages_to_delete);
    }
  }

  /** * {@inheritdoc} */
  protected function linkTemplates() {
    $link_templates = parent::linkTemplates();
    if (\Drupal::moduleHandler()->moduleExists('field_ui')) {
      $link_templates["{$this->entity_type}-field-edit-form"] = 'entity.field_config.' . $this->entity_type . '_field_edit_form';
      $link_templates["{$this->entity_type}-storage-edit-form"] = 'entity.field_config.' . $this->entity_type . '_storage_edit_form';
      $link_templates["{$this->entity_type}-field-delete-form"] = 'entity.field_config.' . $this->entity_type . '_field_delete_form';

      if (isset($link_templates['config-translation-overview'])) {
        $link_templates["config-translation-overview.{$this->entity_type}"] = "entity.field_config.config_translation_overview.{$this->entity_type}";
      }
    }
    return $link_templates;
  }

  

  /** * {@inheritdoc} */
  public function toUrl($rel = 'canonical', array $options = []) {
    if ($this->id() === NULL) {
      throw new EntityMalformedException(sprintf('The "%s" entity cannot have a URI as it does not have an ID', $this->getEntityTypeId()));
    }

    // The links array might contain URI templates set in annotations.     $link_templates = $this->linkTemplates();

    // Links pointing to the current revision point to the actual entity. So     // instead of using the 'revision' link, use the 'canonical' link.     if ($rel === 'revision' && $this instanceof RevisionableInterface && $this->isDefaultRevision()) {
      $rel = 'canonical';
    }

    if (isset($link_templates[$rel])) {
      $route_parameters = $this->urlRouteParameters($rel);
      $route_name = "entity.{$this->entityTypeId}." . str_replace(['-', 'drupal:'], ['_', ''], $rel);
      $uri = new Url($route_name, $route_parameters);
    }