theme.inc

<?php

/**
 * @file
 * The theme system, which controls the output of Drupal.
 *
 * The theme system allows for nearly all output of the Drupal system to be
 * customized by user themes.
 */

use Drupal\Component\Serialization\Json;
use Drupal\Component\Utility\SafeMarkup;
use Drupal\Component\Utility\String;
use Drupal\Component\Utility\UrlHelper;
use Drupal\Component\Utility\Xss;
use Drupal\Core\Config\Config;
use Drupal\Core\Config\StorageException;
use Drupal\Core\Extension\Extension;
use Drupal\Core\Extension\ExtensionNameLengthException;
use Drupal\Core\Page\FeedLinkElement;
use Drupal\Core\Page\LinkElement;
use Drupal\Core\Page\MetaElement;
use Drupal\Core\Template\Attribute;
use Drupal\Core\Theme\ThemeSettings;
use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Render\Element;
use Symfony\Component\HttpFoundation\Request;

/**
 * @defgroup content_flags Content markers
 * @{
 * Markers used by mark.html.twig and node_mark() to designate content.
 *
 * @see mark.html.twig
 * @see node_mark()
 */

/**
 * Mark content as read.
 */
const MARK_READ = 0;

/**
 * Mark content as being new.
 */
const MARK_NEW = 1;

/**
 * Mark content as being updated.
 */
const MARK_UPDATED = 2;

/**
 * A responsive table class; hide table cell on narrow devices.
 *
 * Indicates that a column has medium priority and thus can be hidden on narrow
 * width devices and shown on medium+ width devices (i.e. tablets and desktops).
 */
const RESPONSIVE_PRIORITY_MEDIUM = 'priority-medium';

/**
 * A responsive table class; only show table cell on wide devices.
 *
 * Indicates that a column has low priority and thus can be hidden on narrow
 * and medium viewports and shown on wide devices (i.e. desktops).
 */
const RESPONSIVE_PRIORITY_LOW = 'priority-low';

/**
 * @} End of "defgroup content_flags".