Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\language\Plugin\LanguageNegotiation;
Chris@0: 
Chris@0: use Drupal\language\LanguageNegotiationMethodBase;
Chris@0: use Symfony\Component\HttpFoundation\Request;
Chris@0: 
Chris@0: /**
Chris@0:  * Class that determines the language to be assigned to URLs when none is
Chris@0:  * detected.
Chris@0:  *
Chris@0:  * The language negotiation process has a fallback chain that ends with the
Chris@0:  * default language negotiation method. Each built-in language type has a
Chris@0:  * separate initialization:
Chris@0:  * - Interface language, which is the only configurable one, always gets a valid
Chris@0:  *   value. If no request-specific language is detected, the default language
Chris@0:  *   will be used.
Chris@0:  * - Content language merely inherits the interface language by default.
Chris@0:  * - URL language is detected from the requested URL and will be used to rewrite
Chris@0:  *   URLs appearing in the page being rendered. If no language can be detected,
Chris@0:  *   there are two possibilities:
Chris@0:  *   - If the default language has no configured path prefix or domain, then the
Chris@0:  *     default language is used. This guarantees that (missing) URL prefixes are
Chris@0:  *     preserved when navigating through the site.
Chris@0:  *   - If the default language has a configured path prefix or domain, a
Chris@0:  *     requested URL having an empty prefix or domain is an anomaly that must be
Chris@0:  *     fixed. This is done by introducing a prefix or domain in the rendered
Chris@0:  *     page matching the detected interface language.
Chris@0:  *
Chris@0:  * @LanguageNegotiation(
Chris@0:  *   id = Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationUrlFallback::METHOD_ID,
Chris@0:  *   types = {Drupal\Core\Language\LanguageInterface::TYPE_URL},
Chris@0:  *   weight = 8,
Chris@0:  *   name = @Translation("URL fallback"),
Chris@0:  *   description = @Translation("Use an already detected language for URLs if none is found.")
Chris@0:  * )
Chris@0:  */
Chris@0: class LanguageNegotiationUrlFallback extends LanguageNegotiationMethodBase {
Chris@0: 
Chris@0:   /**
Chris@0:    * The language negotiation method id.
Chris@0:    */
Chris@0:   const METHOD_ID = 'language-url-fallback';
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getLangcode(Request $request = NULL) {
Chris@0:     $langcode = NULL;
Chris@0: 
Chris@0:     if ($this->languageManager) {
Chris@0:       $default = $this->languageManager->getDefaultLanguage();
Chris@0:       $config = $this->config->get('language.negotiation')->get('url');
Chris@0:       $prefix = ($config['source'] == LanguageNegotiationUrl::CONFIG_PATH_PREFIX);
Chris@0: 
Chris@0:       // If the default language is not configured to convey language
Chris@0:       // information, a missing URL language information indicates that URL
Chris@0:       // language should be the default one, otherwise we fall back to an
Chris@0:       // already detected language.
Chris@0:       if (($prefix && empty($config['prefixes'][$default->getId()])) || (!$prefix && empty($config['domains'][$default->getId()]))) {
Chris@0:         $langcode = $default->getId();
Chris@0:       }
Chris@0:       else {
Chris@0:         $langcode = $this->languageManager->getCurrentLanguage()->getId();
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $langcode;
Chris@0:   }
Chris@0: 
Chris@0: }