drupal/modules/field/field.multilingual.inc

242 lines
8.0 KiB
PHP

<?php
// $Id$
/**
* @file
* Multilingual field API helper functions.
*/
/**
* Implements hook_multilingual_settings_changed().
*/
function field_multilingual_settings_changed() {
field_info_cache_clear();
}
/**
* Collects the available languages for the given entity type and field.
*
* If the given field has language support enabled, an array of available
* languages will be returned, otherwise only LANGUAGE_NONE will be returned.
* Since the default value for a 'translatable' entity property is FALSE, we
* ensure that only entities that are able to handle translations actually get
* translatable fields.
*
* @param $entity_type
* The type of the entity the field is attached to, e.g. 'node' or 'user'.
* @param $field
* A field structure.
*
* @return
* An array of valid language codes.
*/
function field_available_languages($entity_type, $field) {
$field_languages = &drupal_static(__FUNCTION__, array());
$field_name = $field['field_name'];
if (!isset($field_languages[$entity_type][$field_name])) {
// If the field has language support enabled we retrieve an (alterable) list
// of enabled languages, otherwise we return just LANGUAGE_NONE.
if (field_is_translatable($entity_type, $field)) {
$languages = field_content_languages();
// Let other modules alter the available languages.
$context = array('entity_type' => $entity_type, 'field' => $field);
drupal_alter('field_available_languages', $languages, $context);
$field_languages[$entity_type][$field_name] = $languages;
}
else {
$field_languages[$entity_type][$field_name] = array(LANGUAGE_NONE);
}
}
return $field_languages[$entity_type][$field_name];
}
/**
* Process the given language suggestion based on the available languages.
*
* If a non-empty language suggestion is provided it must appear among the
* available languages, otherwise it will be ignored.
*
* @param $available_languages
* An array of valid language codes.
* @param $language_suggestion
* A language code or an array of language codes keyed by field name.
* @param $field_name
* The name of the field being processed.
*
* @return
* An array of valid language codes.
*/
function _field_language_suggestion($available_languages, $language_suggestion, $field_name) {
// Handle possible language suggestions.
if (!empty($language_suggestion)) {
// We might have an array of language suggestions keyed by field name.
if (is_array($language_suggestion) && isset($language_suggestion[$field_name])) {
$language_suggestion = $language_suggestion[$field_name];
}
// If we have a language suggestion and the suggested language is available,
// we return only it.
if (in_array($language_suggestion, $available_languages)) {
$available_languages = array($language_suggestion);
}
}
return $available_languages;
}
/**
* Returns available content languages.
*
* The languages that may be associated to fields include LANGUAGE_NONE.
*
* @return
* An array of language codes.
*/
function field_content_languages() {
$languages = language_list('enabled');
return array_keys($languages[1] + array(LANGUAGE_NONE => NULL));
}
/**
* Checks whether a field has language support.
*
* A field has language support enabled if its 'translatable' property is set to
* TRUE, and its entity type has at least one translation handler registered.
*
* @param $entity_type
* The type of the entity the field is attached to.
* @param $field
* A field data structure.
*
* @return
* TRUE if the field can be translated.
*/
function field_is_translatable($entity_type, $field) {
return $field['translatable'] && field_has_translation_handler($entity_type);
}
/**
* Checks if a module is registered as a translation handler for a given entity.
*
* If no handler is passed, simply check if there is any translation handler
* enabled for the given entity type.
*
* @param $entity_type
* The type of the entity whose fields are to be translated.
* @param $handler
* (optional) The name of the handler to be checked. Defaults to NULL.
*
* @return
* TRUE, if the given handler is allowed to manage field translations. If no
* handler is passed, TRUE means there is at least one registered translation
* handler.
*/
function field_has_translation_handler($entity_type, $handler = NULL) {
$entity_info = entity_get_info($entity_type);
if (isset($handler)) {
return !empty($entity_info['translation'][$handler]);
}
elseif (isset($entity_info['translation'])) {
foreach ($entity_info['translation'] as $handler_info) {
// The translation handler must use a non-empty data structure.
if (!empty($handler_info)) {
return TRUE;
}
}
}
return FALSE;
}
/**
* Ensures that a given language code is valid.
*
* Checks whether the given language is one of the enabled languages. Otherwise,
* it returns the current, global language; or the site's default language, if
* the additional parameter $default is TRUE.
*
* @param $langcode
* The language code to validate.
* @param $default
* Whether to return the default language code or the current language code in
* case $langcode is invalid.
* @return
* A valid language code.
*/
function field_valid_language($langcode, $default = TRUE) {
$enabled_languages = field_content_languages();
if (in_array($langcode, $enabled_languages)) {
return $langcode;
}
global $language_content;
return $default ? language_default('language') : $language_content->language;
}
/**
* Returns the display language for the fields attached to the given entity.
*
* The actual language for each given field is determined based on the requested
* language and the actual data available in the fields themselves.
* If there is no registered translation handler for the given entity type, the
* display language to be used is just LANGUAGE_NONE, as no other language code
* is allowed by field_available_languages().
* If translation handlers are found, we let modules provide alternative display
* languages for fields not having the requested language available.
* Core language fallback rules are provided by locale_field_language_fallback()
* which is called by locale_field_language_alter().
*
* @param $entity_type
* The type of $entity.
* @param $entity
* The entity to be displayed.
* @param $field_name
* (optional) The name of the field to be displayed. Defaults to NULL. If
* no value is specified, the display languages for every field attached to
* the given entity will be returned.
* @param $langcode
* (optional) The language code $entity has to be displayed in. Defaults to
* NULL. If no value is given the current language will be used.
*
* @return
* A language code if a field name is specified, an array of language codes
* keyed by field name otherwise.
*/
function field_language($entity_type, $entity, $field_name = NULL, $langcode = NULL) {
$display_languages = &drupal_static(__FUNCTION__, array());
list($id, , $bundle) = entity_extract_ids($entity_type, $entity);
$langcode = field_valid_language($langcode, FALSE);
if (!isset($display_languages[$entity_type][$id][$langcode])) {
$display_language = array();
// By default display language is set to LANGUAGE_NONE. It is up to
// translation handlers to implement language fallback rules.
foreach (field_info_instances($entity_type, $bundle) as $instance) {
$display_language[$instance['field_name']] = LANGUAGE_NONE;
}
if (field_has_translation_handler($entity_type)) {
$context = array(
'entity_type' => $entity_type,
'entity' => $entity,
'language' => $langcode,
);
drupal_alter('field_language', $display_language, $context);
}
$display_languages[$entity_type][$id][$langcode] = $display_language;
}
$display_language = $display_languages[$entity_type][$id][$langcode];
// Single-field mode.
if (isset($field_name)) {
return isset($display_language[$field_name]) ? $display_language[$field_name] : FALSE;
}
return $display_language;
}