drupal/core/themes/seven/seven.theme

<?php

/**
 * @file
 * Functions to support theming in the Seven theme.
 */

use Drupal\Component\Utility\Xss;
use Drupal\Component\Utility\String;
use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_preprocess_HOOK() for page templates.
 */
function seven_preprocess_page(&$variables) {
  /** @var \Drupal\Core\Page\HtmlPage $page_object */
  $page_object = $variables['page']['#page'];
  $attributes = $page_object->getBodyAttributes();
  $classes = $attributes['class'];
  // Add information about the number of sidebars.

  if (!empty($variables['page']['sidebar_first'])) {
    $classes[] = 'layout-one-sidebar';
    $classes[] = 'layout-sidebar-first';
  }
  else {
    $classes[] = 'layout-no-sidebars';
  }
  $attributes['class'] = $classes;

  $variables['primary_local_tasks'] = $variables['tabs'];
  unset($variables['primary_local_tasks']['#secondary']);
  $variables['secondary_local_tasks'] = array(
    '#theme' => 'menu_local_tasks',
    '#secondary' => isset($variables['tabs']['#secondary']) ? $variables['tabs']['#secondary'] : '',
  );
}

/**
 * Implements hook_pre_render_HOOK() for menu-local-tasks templates.
 *
 * Use preprocess hook to set #attached to child elements
 * because they will be processed by Twig and drupal_render will
 * be invoked.
 */
function seven_preprocess_menu_local_tasks(&$variables) {
  if (!empty($variables['primary'])) {
    $variables['primary']['#attached'] = array(
      'library' => array(
        'seven/drupal.nav-tabs',
      ),
    );
  }
  elseif (!empty($variables['secondary'])) {
    $variables['secondary']['#attached'] = array(
      'library' => array(
        'seven/drupal.nav-tabs',
      ),
    );
  }
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-task templates.
 */
function seven_preprocess_menu_local_task(&$variables) {
  $variables['attributes']['class'][] = 'tabs__tab';
}

/**
 * Implements hook_preprocess_HOOK() for list of available node type templates.
 */
function seven_preprocess_node_add_list(&$variables) {
  if (!empty($variables['content'])) {
    foreach ($variables['content'] as $type) {
      $variables['types'][$type->type]['label'] = String::checkPlain($type->name);
      $variables['types'][$type->type]['description'] = Xss::filterAdmin($type->description);
      $variables['types'][$type->type]['url'] = \Drupal::url('node.add', array('node_type' => $type->type));
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for block content add list templates.
 *
 * Displays the list of available custom block types for creation, adding
 * separate variables for the label, description, and url.
 */
function seven_preprocess_block_content_add_list(&$variables) {
  if (!empty($variables['content'])) {
    foreach ($variables['content'] as $type) {
      $variables['types'][$type->id()]['label'] = String::checkPlain($type->label());
      $variables['types'][$type->id()]['description'] = Xss::filterAdmin($type->description);
      $options = array('query' => \Drupal::request()->query->all());
      $variables['types'][$type->id()]['url'] = \Drupal::url('block_content.add_form', array('block_content_type' => $type->id()), $options);
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for block admin page templates.
 */
function seven_preprocess_admin_block_content(&$variables) {
  if (!empty($variables['content'])) {
    foreach ($variables['content'] as $key => $item) {
      $variables['content'][$key]['url'] = $item['url']->toString();
    }
  }
}

/**
 * Implements hook_preprocess_HOOK() for tablesort indicator templates.
 *
 * Uses Seven's image versions, so the arrows show up as black and not gray on
 * gray.
 */
function seven_preprocess_tablesort_indicator(&$variables) {
  $theme_path = drupal_get_path('theme', 'seven');
  $variables['arrow_asc'] = file_create_url($theme_path . '/images/arrow-asc.png');
  $variables['arrow_desc'] = file_create_url($theme_path . '/images/arrow-desc.png');
}

/**
 * Implements hook_preprocess_HOOK() for menu-local-action templates.
 */
function seven_preprocess_menu_local_action(array &$variables) {
  $variables['link']['#options']['attributes']['class'][] = 'button--primary';
  $variables['link']['#options']['attributes']['class'][] = 'button--small';

  // We require Modernizr's touch test for button styling.
  $variables['#attached']['library'][] = 'core/modernizr';
}

/**
 * Implements hook_element_info_alter().
 */
function seven_element_info_alter(&$type) {
  // We require Modernizr for button styling.
  if (isset($type['button'])) {
    $type['button']['#attached']['library'][] = 'core/modernizr';
  }
}

/**
 * Implements hook_preprocess_install_page().
 */
function seven_preprocess_install_page(&$variables) {
  $page_object = $variables['page']['#page'];
  $attributes = $page_object->getHtmlAttributes();
  $classes = $attributes['class'];
  $classes[] = 'install-background';
  $attributes['class'] = $classes;

  // Seven has custom styling for the install page.
  $variables['#attached']['library'][] = 'seven/install-page';
}

/**
 * Implements hook_preprocess_maintenance_page().
 */
function seven_preprocess_maintenance_page(&$variables) {
  $page_object = $variables['page']['#page'];
  $attributes = $page_object->getHtmlAttributes();
  $classes = $attributes['class'];
  $classes[] = 'maintenance-background';
  $attributes['class'] = $classes;

  // Seven has custom styling for the maintenance page.
  $variables['#attached']['library'][] = 'seven/maintenance-page';
}

/**
 * Implements hook_form_BASE_FORM_ID_alter().
 *
 * Changes vertical tabs to container and adds meta information.
 */
function seven_form_node_form_alter(&$form, FormStateInterface $form_state) {
  /** @var \Drupal\node\NodeInterface $node */
  $node = $form_state->getFormObject()->getEntity();

  $form['#theme'] = array('node_edit_form');
  $form['#attached']['css'][] = drupal_get_path('module', 'node') . '/css/node.module.css';

  $form['advanced']['#type'] = 'container';
  $is_new = !$node->isNew() ? format_date($node->getChangedTime(), 'short') : t('Not saved yet');
  $form['meta'] = array(
    '#attributes' => array('class' => array('entity-meta-header')),
    '#type' => 'container',
    '#group' => 'advanced',
    '#weight' => -100,
    'published' => array(
      '#type' => 'item',
      '#wrapper_attributes' => array('class' => array('published')),
      '#markup' => $node->isPublished() ? t('Published') : t('Not published'),
      '#access' => !$node->isNew(),
    ),
    'changed' => array(
      '#type' => 'item',
      '#wrapper_attributes' => array('class' => array('changed', 'container-inline')),
      '#markup' => '<h4 class="label inline">' . t('Last saved') . '</h4> ' . $is_new,
    ),
    'author' => array(
      '#type' => 'item',
      '#wrapper_attributes' => array('class' => array('author', 'container-inline')),
      '#markup' => '<h4 class="label inline">' . t('Author') . '</h4> ' . $node->getOwner()->getUsername(),
    ),
  );
  $form['revision_information']['#type'] = 'container';
  $form['revision_information']['#group'] = 'meta';
}

function seven_preprocess_html(&$variables) {
  // If on a node add or edit page, add a node-layout class.
  $path_args = explode('/', \Drupal::request()->getPathInfo());
  if ($suggestions = theme_get_suggestions($path_args, 'page', '-')) {
    foreach ($suggestions as $suggestion) {
      if ($suggestion === 'page-node-edit' || strpos($suggestion, 'page-node-add') !== FALSE) {
        $variables['attributes']['class'][] = drupal_html_class('node-form-layout');
      }
    }
  }
}