Convert language_element_info() to Element classes

Here is the first attempt to create the class.

1. +++ b/core/modules/language/language.module
   @@ -180,103 +180,6 @@ function language_process_language_select($element) {
   - * Process handler for the language_configuration form element.
   
   +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +  /**
   +   * @param array $element
   

   Copy this one liner here.

2. +++ b/core/modules/language/language.module
   @@ -180,103 +180,6 @@ function language_process_language_select($element) {
   -      language_save_default_configuration($values['entity_type'], $values['bundle'],  $form_state->getValue($element_name));
   
   +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +        \Drupal::config('language.settings')->set(language_get_default_configuration_settings_key($values['entity_type'], $values['bundle']), array('langcode' => $values['langcode'], 'language_show' => $values['language_show']))->save();
   

   I don't think changing this is in scope.

3. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +* provides language element configuration.
   +*/
   

   This should be indented one space, and start with a capital P. Also, it needs an @FormElement("language_configuration") annotation

4. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +class LanguageConfig extends FormElement {
   

   This class should be LanguageConfiguration

5. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +    $types['language_configuration'] = array(
   ...
   +    return $types;
   

   You can just return array(, no need for a $types array

6. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +      '#process' => array(array($class, 'LanguageConfigprocess')),
   ...
   +  public static function LanguageConfigprocess($element, FormStateInterface $form_state, &$form) {
   

   Please rename this 'processLanguageConfig'

7. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +        $form['actions']['submit']['#submit'][] = 'LanguageConfigElementSubmit';
   ...
   +        $form['#submit'][] = 'LanguageConfigElementSubmit';
   ...
   +  protected static function LanguageConfigElementSubmit(&$form, FormStateInterface $form_state) {
   

   submitLanguageConfiguration

8. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +   * @return array
   +   * Returns default language list.
   

   Switch this order.

9. +++ b/core/modules/language/src/Element/LanguageConfig.php
   @@ -0,0 +1,119 @@
   +  protected static function LanguageConfigDefaultOptions() {
   

   getDefaultOptions

Thank You @tim.plunkett.
Corrected #2 and here is the patch.

Thank you @almaudoh.
Updated comment #6.

+++ b/core/modules/language/src/Element/LanguageConfig.php
@@ -0,0 +1,121 @@
+        $form['actions']['submit']['#submit'][] = 'submitLanguageConfiguration';
...
+        $form['#submit'][] = 'submitLanguageConfiguration';
...
+  protected static function submitLanguageConfiguration(&$form, FormStateInterface $form_state) {

This is not valid PHP. It should be array(get_called_class(), 'submitLanguageConfiguration')

And the method must be public.

Corrected #9. Thank you @tim.plunkett.

So it turns out that language_configuration_element_submit() is still used in several places in core, so we should not move it into this element yet.

Also, the file was named incorrectly.

This will still fail the CMI tests.

Let's add to D8MI sprint.

Reminder that there is nothing to do here until #2326409: Annotate render element plugins is done.

Rerolled for now without the hook_element_info() removal in light of #2326409: Annotate render element plugins

Shouldn't have removed language_configuration_element_submit().

1. +++ b/core/modules/language/src/Element/LanguageConfiguration.php
   @@ -0,0 +1,107 @@
   +      // Determine where to attach the language_configuration element submit handler.
   +      // @todo Form API: Allow form widgets/sections to declare #submit handlers.
   

   more then 80 chars.

2. +++ b/core/modules/language/src/Element/LanguageConfiguration.php
   @@ -0,0 +1,107 @@
   +      'site_default' => t("Site's default language (!language)", array('!language' => \Drupal::languageManager()->getDefaultLanguage()->name)),
   ...
   +    $languages = \Drupal::languageManager()->getLanguages(LanguageInterface::STATE_ALL);
   

   We can inject these.

Messed up the interdiff, sorry.

Thanks for the fixes.

Committed and pushed to 8.x. Thanks!

Thanks all!