Chris@0: <?php
Chris@0: 
Chris@0: /**
Chris@0:  * @file
Chris@0:  * Hooks provided by the base system for language support.
Chris@0:  */
Chris@0: 
Chris@0: use Drupal\Core\Language\LanguageInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * @defgroup i18n Internationalization
Chris@0:  * @{
Chris@0:  * Internationalization and translation
Chris@0:  *
Chris@0:  * The principle of internationalization is that it should be possible to make a
Chris@0:  * Drupal site in any language (or a multi-lingual site), where only content in
Chris@0:  * the desired language is displayed for any particular page request. In order
Chris@0:  * to make this happen, developers of modules, themes, and installation profiles
Chris@0:  * need to make sure that all of the displayable content and user interface (UI)
Chris@0:  * text that their project deals with is internationalized properly, so that it
Chris@0:  * can be translated using the standard Drupal translation mechanisms.
Chris@0:  *
Chris@0:  * @section internationalization Internationalization
Chris@0:  * Different @link info_types types of information in Drupal @endlink have
Chris@0:  * different methods for internationalization, and different portions of the
Chris@0:  * UI also have different methods for internationalization. Here is a list of
Chris@0:  * the different mechanisms for internationalization, and some notes:
Chris@0:  * - UI text is always put into code and related files in English.
Chris@0:  * - Any time UI text is displayed using PHP code, it should be passed through
Chris@0:  *   either the global t() function or a t() method on the class. If it
Chris@0:  *   involves plurals, it should be passed through either the global
Chris@0:  *   \Drupal\Core\StringTranslation\PluralTranslatableMarkup::createFromTranslatedString()
Chris@0:  *   or a formatPlural() method on the class. Use
Chris@0:  *   \Drupal\Core\StringTranslation\StringTranslationTrait to get these methods
Chris@0:  *   into a class.
Chris@0:  * - Dates displayed in the UI should be passed through the 'date' service
Chris@0:  *   class's format() method. Again see the Services topic; the method to
Chris@0:  *   call is \Drupal\Core\Datetime\Date::format().
Chris@0:  * - Some YML files contain UI text that is automatically translatable:
Chris@0:  *   - *.routing.yml files: route titles. This also applies to
Chris@0:  *     *.links.task.yml, *.links.action.yml, and *.links.contextual.yml files.
Chris@0:  *   - *.info.yml files: module names and descriptions.
Chris@0:  * - For configuration, make sure any configuration that is displayable to
Chris@0:  *   users is marked as translatable in the configuration schema. Configuration
Chris@0:  *   types label, text, and date_format are translatable; string is
Chris@0:  *   non-translatable text. See the @link config_api Config API topic @endlink
Chris@0:  *   for more information.
Chris@0:  * - For annotation, make sure that any text that is displayable in the UI
Chris@0:  *   is wrapped in \@Translation(). See the
Chris@0:  *   @link plugin_translatable Plugin translatables topic @endlink for more
Chris@0:  *   information.
Chris@0:  * - Content entities are translatable if they have
Chris@0:  *   @code
Chris@0:  *   translatable = TRUE,
Chris@0:  *   @endcode
Chris@0:  *   in their annotation. The use of entities to store user-editable content to
Chris@0:  *   be displayed in the site is highly recommended over creating your own
Chris@0:  *   method for storing, retrieving, displaying, and internationalizing content.
Chris@0:  * - For Twig templates, use 't' or 'trans' filters to indicate translatable
Chris@0:  *   text. See https://www.drupal.org/node/2133321 for more information.
Chris@0:  * - In JavaScript code, use the Drupal.t() and Drupal.formatPlural() functions
Chris@0:  *   (defined in core/misc/drupal.js) to translate UI text.
Chris@0:  * - If you are using a custom module, theme, etc. that is not hosted on
Chris@0:  *   Drupal.org, see
Chris@0:  *   @link interface_translation_properties Interface translation properties topic @endlink
Chris@0:  *   for information on how to make sure your UI text is translatable.
Chris@0:  *
Chris@0:  * @section translation Translation
Chris@0:  * Once your data and user interface are internationalized, the following Core
Chris@0:  * modules are used to translate it into different languages (machine names of
Chris@0:  * modules in parentheses):
Chris@0:  * - Language (language): Define which languages are active on the site.
Chris@0:  * - Interface Translation (locale): Translate UI text.
Chris@0:  * - Content Translation (content_translation): Translate content entities.
Chris@0:  * - Configuration Translation (config_translation): Translate configuration.
Chris@0:  *
Chris@0:  * The Interface Translation module deserves special mention, because besides
Chris@0:  * providing a UI for translating UI text, it also imports community
Chris@0:  * translations from the
Chris@0:  * @link https://localize.drupal.org Drupal translation server. @endlink If
Chris@0:  * UI text and provided configuration in Drupal Core and contributed modules,
Chris@0:  * themes, and installation profiles is properly internationalized (as described
Chris@0:  * above), the text is automatically added to the translation server for
Chris@0:  * community members to translate, via *.po files that are generated by
Chris@0:  * scanning the project files.
Chris@0:  *
Chris@0:  * @section context Translation string sharing and context
Chris@0:  * By default, translated strings are only translated once, no matter where
Chris@0:  * they are being used. For instance, there are many forms with Save
Chris@0:  * buttons on them, and they all would have t('Save') in their code. The
Chris@0:  * translation system will only store this string once in the translation
Chris@0:  * database, so that if the translation is updated, all forms using that text
Chris@0:  * will get the updated translation.
Chris@0:  *
Chris@0:  * Because the source of translation strings is English, and some words in
Chris@0:  * English have multiple meanings or uses, this centralized, shared translation
Chris@0:  * string storage can sometimes lead to ambiguous translations that are not
Chris@0:  * correct for every place the string is used. As an example, the English word
Chris@0:  * "May", in a string by itself, could be part of a list of full month names or
Chris@0:  * part of a list of 3-letter abbreviated month names. So, in languages where
Chris@0:  * the month name for May is longer than 3 letters, you'd need to translate May
Chris@0:  * differently depending on how it's being used. To address this problem, the
Chris@0:  * translation system includes the concept of the "context" of a translated
Chris@0:  * string, which can be used to disambiguate text for translators, and obtain
Chris@0:  * the correct translation for each usage of the string.
Chris@0:  *
Chris@0:  * Here are some examples of how to provide translation context with strings, so
Chris@0:  * that this information can be included in *.po files, displayed on the
Chris@0:  * localization server for translators, and used to obtain the correct
Chris@0:  * translation in the user interface:
Chris@0:  * @code
Chris@0:  * // PHP code
Chris@18:  * t('May', [], ['context' => 'Long month name']);
Chris@0:  * \Drupal::translation()->formatPlural($count, '1 something',
Chris@18:  *   '@count somethings', [], ['context' => 'My context']);
Chris@0:  *
Chris@0:  * // JavaScript code
Chris@0:  * Drupal.t('May', {}, {'context': 'Long month name'});
Chris@0:  * Drupal.formatPlural(count, '1 something', '@count somethings', {},
Chris@0:  *   {'context': 'My context'});
Chris@0:  *
Chris@0:  * // *.links.yml file
Chris@0:  * title: 'May'
Chris@0:  * title_context: 'Long month name'
Chris@0:  *
Chris@0:  * // *.routing.yml file
Chris@0:  * my.route.name:
Chris@0:  *   pattern: '/something'
Chris@0:  *   defaults:
Chris@0:  *     _title: 'May'
Chris@0:  *     _title_context: 'Long month name'
Chris@0:  *
Chris@0:  * // Config schema to say that a certain piece of configuration should be
Chris@0:  * // translatable using the Config Translation API. Note that the schema label
Chris@0:  * // is also translatable, but it cannot have context.
Chris@0:  * date_format:
Chris@0:  *  type: string
Chris@0:  *  label: 'PHP date format'
Chris@0:  *  translatable: true
Chris@0:  *  translation context: 'PHP date format'
Chris@0:  *
Chris@0:  * // Twig template
Chris@0:  * {% trans with {'context': 'Long month name'} %}
Chris@0:  *  May
Chris@0:  * {% endtrans %}
Chris@0:  * @endcode
Chris@0:  *
Chris@0:  * @see transliteration
Chris@0:  * @see t()
Chris@0:  * @}
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * @addtogroup hooks
Chris@0:  * @{
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * Perform alterations on language switcher links.
Chris@0:  *
Chris@0:  * A language switcher link may need to point to a different path or use a
Chris@0:  * translated link text before going through the link generator, which will
Chris@0:  * just handle the path aliases.
Chris@0:  *
Chris@0:  * @param array $links
Chris@0:  *   Nested array of links keyed by language code.
Chris@0:  * @param string $type
Chris@0:  *   The language type the links will switch.
Chris@0:  * @param \Drupal\Core\Url $url
Chris@0:  *   The URL the switch links will be relative to.
Chris@0:  */
Chris@0: function hook_language_switch_links_alter(array &$links, $type, \Drupal\Core\Url $url) {
Chris@0:   $language_interface = \Drupal::languageManager()->getCurrentLanguage();
Chris@0: 
Chris@0:   if ($type == LanguageInterface::TYPE_CONTENT && isset($links[$language_interface->getId()])) {
Chris@0:     foreach ($links[$language_interface->getId()] as $link) {
Chris@0:       $link['attributes']['class'][] = 'active-language';
Chris@0:     }
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * @} End of "addtogroup hooks".
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * @defgroup transliteration Transliteration
Chris@0:  * @{
Chris@0:  * Transliterate from Unicode to US-ASCII
Chris@0:  *
Chris@0:  * Transliteration is the process of translating individual non-US-ASCII
Chris@0:  * characters into ASCII characters, which specifically does not transform
Chris@0:  * non-printable and punctuation characters in any way. This process will always
Chris@0:  * be both inexact and language-dependent. For instance, the character Ö (O with
Chris@0:  * an umlaut) is commonly transliterated as O, but in German text, the
Chris@0:  * convention would be to transliterate it as Oe or OE, depending on the context
Chris@0:  * (beginning of a capitalized word, or in an all-capital letter context).
Chris@0:  *
Chris@0:  * The Drupal default transliteration process transliterates text character by
Chris@0:  * character using a database of generic character transliterations and
Chris@0:  * language-specific overrides. Character context (such as all-capitals
Chris@0:  * vs. initial capital letter only) is not taken into account, and in
Chris@0:  * transliterations of capital letters that result in two or more letters, by
Chris@0:  * convention only the first is capitalized in the Drupal transliteration
Chris@0:  * result. Also, only Unicode characters of 4 bytes or less can be
Chris@0:  * transliterated in the base system; language-specific overrides can be made
Chris@0:  * for longer Unicode characters. So, the process has limitations; however,
Chris@0:  * since the reason for transliteration is typically to create machine names or
Chris@0:  * file names, this should not really be a problem. After transliteration,
Chris@0:  * other transformation or validation may be necessary, such as converting
Chris@0:  * spaces to another character, removing non-printable characters,
Chris@0:  * lower-casing, etc.
Chris@0:  *
Chris@0:  * Here is a code snippet to transliterate some text:
Chris@0:  * @code
Chris@0:  * // Use the current default interface language.
Chris@0:  * $langcode = \Drupal::languageManager()->getCurrentLanguage()->getId();
Chris@0:  * // Instantiate the transliteration class.
Chris@0:  * $trans = \Drupal::transliteration();
Chris@0:  * // Use this to transliterate some text.
Chris@0:  * $transformed = $trans->transliterate($string, $langcode);
Chris@0:  * @endcode
Chris@0:  *
Chris@0:  * Drupal Core provides the generic transliteration character tables and
Chris@0:  * overrides for a few common languages; modules can implement
Chris@0:  * hook_transliteration_overrides_alter() to provide further language-specific
Chris@0:  * overrides (including providing transliteration for Unicode characters that
Chris@0:  * are longer than 4 bytes). Modules can also completely override the
Chris@0:  * transliteration classes in \Drupal\Core\CoreServiceProvider.
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * Provide language-specific overrides for transliteration.
Chris@0:  *
Chris@0:  * If the overrides you want to provide are standard for your language, consider
Chris@0:  * providing a patch for the Drupal Core transliteration system instead of using
Chris@0:  * this hook. This hook can be used temporarily until Drupal Core's
Chris@0:  * transliteration tables are fixed, or for sites that want to use a
Chris@0:  * non-standard transliteration system.
Chris@0:  *
Chris@0:  * @param array $overrides
Chris@0:  *   Associative array of language-specific overrides whose keys are integer
Chris@0:  *   Unicode character codes, and whose values are the transliterations of those
Chris@0:  *   characters in the given language, to override default transliterations.
Chris@0:  * @param string $langcode
Chris@0:  *   The code for the language that is being transliterated.
Chris@0:  *
Chris@0:  * @ingroup hooks
Chris@0:  */
Chris@0: function hook_transliteration_overrides_alter(&$overrides, $langcode) {
Chris@0:   // Provide special overrides for German for a custom site.
Chris@0:   if ($langcode == 'de') {
Chris@0:     // The core-provided transliteration of Ä is Ae, but we want just A.
Chris@0:     $overrides[0xC4] = 'A';
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * @} End of "defgroup transliteration".
Chris@0:  */