CurrentLanguageContext.php

<?php

namespace Drupal\Core\Language\ContextProvider;

use Drupal\Core\Cache\CacheableMetadata;
use Drupal\Core\Language\LanguageManagerInterface;
use Drupal\Core\Plugin\Context\Context;
use Drupal\Core\Plugin\Context\ContextDefinition;
use Drupal\Core\Plugin\Context\ContextProviderInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;

/**
 * Sets the current language as a context.
 */
class CurrentLanguageContext implements ContextProviderInterface {
    use StringTranslationTrait;
    
    /**
     * The language manager.
     *
     * @var \Drupal\Core\Language\LanguageManagerInterface
     */
    protected $languageManager;
    
    /**
     * Constructs a new CurrentLanguageContext.
     *
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     */
    public function __construct(LanguageManagerInterface $language_manager) {
        $this->languageManager = $language_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRuntimeContexts(array $unqualified_context_ids) {
        // Add a context for each language type.
        $language_types = $this->languageManager
            ->getLanguageTypes();
        $info = $this->languageManager
            ->getDefinedLanguageTypesInfo();
        if ($unqualified_context_ids) {
            foreach ($unqualified_context_ids as $unqualified_context_id) {
                if (array_search($unqualified_context_id, $language_types) === FALSE) {
                    unset($language_types[$unqualified_context_id]);
                }
            }
        }
        $result = [];
        foreach ($language_types as $type_key) {
            if (isset($info[$type_key]['name'])) {
                $context = new Context(new ContextDefinition('language', $info[$type_key]['name']), $this->languageManager
                    ->getCurrentLanguage($type_key));
                $cacheability = new CacheableMetadata();
                $cacheability->setCacheContexts([
                    'languages:' . $type_key,
                ]);
                $context->addCacheableDependency($cacheability);
                $result[$type_key] = $context;
            }
        }
        return $result;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getAvailableContexts() {
        return $this->getRuntimeContexts([]);
    }

}