Issue #2505197 by Arskiainen, jaimeguzman, tstoeckler: Add a @see + docs about language_element_info_alter() to LanguageSelect

core/lib/Drupal/Core/Render/Element/LanguageSelect.php

@@ -12,7 +12,11 @@ use Drupal\Core\Language\LanguageInterface;
 /**
  * Provides a form element for selecting a language.
  *
- * @see \Drupal\Core\Render\Element\Select
+ * This does not render an actual form element, but always returns the value of
+ * the default language. It is then extended by Language module via
+ * language_element_info_alter() to provide a proper language selector.
+ *
+ * @see language_element_info_alter()
  *
  * @FormElement("language_select")
  */

core/modules/language/language.module

@@ -120,6 +120,9 @@ function language_theme() {
 
 /**
  * Implements hook_element_info_alter().
+ *
+ * @see \Drupal\Core\Render\Element\LanguageSelect
+ * @see \Drupal\Core\Render\Element\Select
  */
 function language_element_info_alter(&$type) {
   // Alter the language_select element so that it will be rendered like a select