public static VerticalTabs::preRenderVerticalTabs($element)

public static OutputStrategyInterface::renderFrom

public MetadataBubblingUrlGenerator::__

Provides a form submit button. Submit buttons are processed the same as regular buttons, except they trigger the form's submit handler.

public Hidden::getInfo() Returns the

protected HtmlResponseAttachmentsPr

public AttachmentsInterface::getAttachments()

Defines an interface for responses that can expose #attached metadata. @todo If in Drupal 9, we remove attachments other than assets (libraries

hook_preprocess_HOOK(&$variables) Preprocess theme variables for a specific theme hook.

public static Email::validateEmail(&$element, FormStateInterface $form_state