Void elements do not contain values or closing tags. See also

public static Actions::processActions(&$element, FormStateInterface $form_state

Provides a form element for a single checkbox. Properties: #return_value: The value to

Provides a base class for form element plugins. Form elements are a subset of render elements, representing elements for HTML forms, which can

Provides a form element for a submit button with an image. Plugin annotation

Provides a render element for displaying the label for a form element. Labels are generated automatically from element properties during processing

public Radio::getInfo() Returns the element

public static PasswordConfirm::valueCallback(&$element

Provides a display-only form element with an optional title and description. Note: since this is a read-only field, setting the #required property

public static Radios::valueCallback(&$element, $input, FormStateInterface