drupal/core/modules/language/language.negotiation.inc

582 lines
20 KiB
PHP

<?php
/**
* @file
* Language negotiation functions.
*/
/**
* The language is determined using path prefix or domain.
*/
const LANGUAGE_NEGOTIATION_URL = 'language-url';
/**
* The language is set based on the browser language settings.
*/
const LANGUAGE_NEGOTIATION_BROWSER = 'language-browser';
/**
* The language is determined using the current interface language.
*/
const LANGUAGE_NEGOTIATION_INTERFACE = 'language-interface';
/**
* If no URL language, language is determined using an already detected one.
*/
const LANGUAGE_NEGOTIATION_URL_FALLBACK = 'language-url-fallback';
/**
* The language is set based on the user language settings.
*/
const LANGUAGE_NEGOTIATION_USER = 'language-user';
/**
* The language is set based on the user admin language settings.
*/
const LANGUAGE_NEGOTIATION_USER_ADMIN = 'language-user-admin';
/**
* The language is set based on the request/session parameters.
*/
const LANGUAGE_NEGOTIATION_SESSION = 'language-session';
/**
* URL language negotiation: use the path prefix as URL language indicator.
*/
const LANGUAGE_NEGOTIATION_URL_PREFIX = 0;
/**
* URL language negotiation: use the domain as URL language indicator.
*/
const LANGUAGE_NEGOTIATION_URL_DOMAIN = 1;
/**
* Identifies the language from the current interface language.
*
* @return
* The current interface language code.
*/
function language_from_interface() {
return language(LANGUAGE_TYPE_INTERFACE)->langcode;
}
/**
* Identify language from the Accept-language HTTP header we got.
*
* The algorithm works as follows:
* - map browser language codes to Drupal language codes.
* - order all browser language codes by qvalue from high to low.
* - add generic browser language codes if they aren't already specified
* but with a slightly lower qvalue.
* - find the most specific Drupal language code with the highest qvalue.
* - if 2 or more languages are having the same qvalue, respect the order of
* them inside the $languages array.
*
* We perform browser accept-language parsing only if page cache is disabled,
* otherwise we would cache a user-specific preference.
*
* @param $languages
* An array of language objects for enabled languages ordered by weight.
*
* @return
* A valid language code on success, FALSE otherwise.
*/
function language_from_browser($languages) {
if (empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
return FALSE;
}
// The Accept-Language header contains information about the language
// preferences configured in the user's browser / operating system. RFC 2616
// (section 14.4) defines the Accept-Language header as follows:
// Accept-Language = "Accept-Language" ":"
// 1#( language-range [ ";" "q" "=" qvalue ] )
// language-range = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" )
// Samples: "hu, en-us;q=0.66, en;q=0.33", "hu,en-us;q=0.5"
$browser_langcodes = array();
if (preg_match_all('@(?<=[, ]|^)([a-zA-Z-]+|\*)(?:;q=([0-9.]+))?(?:$|\s*,\s*)@', trim($_SERVER['HTTP_ACCEPT_LANGUAGE']), $matches, PREG_SET_ORDER)) {
// Load custom mappings to support browsers that are sending non standard
// language codes.
$mappings = language_get_browser_drupal_langcode_mappings();
foreach ($matches as $match) {
if ($mappings) {
$langcode = strtolower($match[1]);
foreach ($mappings as $browser_langcode => $drupal_langcode) {
if ($langcode == $browser_langcode) {
$match[1] = $drupal_langcode;
}
}
}
// We can safely use strtolower() here, tags are ASCII.
// RFC2616 mandates that the decimal part is no more than three digits,
// so we multiply the qvalue by 1000 to avoid floating point comparisons.
$langcode = strtolower($match[1]);
$qvalue = isset($match[2]) ? (float) $match[2] : 1;
$browser_langcodes[$langcode] = (int) ($qvalue * 1000);
}
}
// We should take pristine values from the HTTP headers, but Internet Explorer
// from version 7 sends only specific language tags (eg. fr-CA) without the
// corresponding generic tag (fr) unless explicitly configured. In that case,
// we assume that the lowest value of the specific tags is the value of the
// generic language to be as close to the HTTP 1.1 spec as possible.
// See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4 and
// http://blogs.msdn.com/b/ie/archive/2006/10/17/accept-language-header-for-internet-explorer-7.aspx
asort($browser_langcodes);
foreach ($browser_langcodes as $langcode => $qvalue) {
// For Chinese languages the generic tag is either zh-hans or zh-hant, so we
// need to handle this separately, we can not split $langcode on the
// first occurence of '-' otherwise we get a non-existing language zh.
// All other languages use a langcode without a '-', so we can safely split
// on the first occurence of it.
$generic_tag = '';
if (strlen($langcode) > 7 && (substr($langcode, 0, 7) == 'zh-hant' || substr($langcode, 0, 7) == 'zh-hans')) {
$generic_tag = substr($langcode, 0, 7);
}
else {
$generic_tag = strtok($langcode, '-');
}
if (!empty($generic_tag) && !isset($browser_langcodes[$generic_tag])) {
// Add the generic langcode, but make sure it has a lower qvalue as the
// more specific one, so the more specific one gets selected if it's
// defined by both the browser and Drupal.
$browser_langcodes[$generic_tag] = $qvalue - 0.1;
}
}
// Find the enabled language with the greatest qvalue, following the rules of
// RFC 2616 (section 14.4). If several languages have the same qvalue, prefer
// the one with the greatest weight.
$best_match_langcode = FALSE;
$max_qvalue = 0;
foreach ($languages as $langcode => $language) {
// Language tags are case insensitive (RFC2616, sec 3.10).
$langcode = strtolower($langcode);
// If nothing matches below, the default qvalue is the one of the wildcard
// language, if set, or is 0 (which will never match).
$qvalue = isset($browser_langcodes['*']) ? $browser_langcodes['*'] : 0;
// Find the longest possible prefix of the browser-supplied language ('the
// language-range') that matches this site language ('the language tag').
$prefix = $langcode;
do {
if (isset($browser_langcodes[$prefix])) {
$qvalue = $browser_langcodes[$prefix];
break;
}
}
while ($prefix = substr($prefix, 0, strrpos($prefix, '-')));
// Find the best match.
if ($qvalue > $max_qvalue) {
$best_match_langcode = $language->langcode;
$max_qvalue = $qvalue;
}
}
return $best_match_langcode;
}
/**
* Identify language from the user preferences.
*
* @param $languages
* An array of valid language objects.
*
* @return
* A valid language code on success, FALSE otherwise.
*/
function language_from_user($languages) {
// User preference (only for authenticated users).
global $user;
if ($user->uid && !empty($user->preferred_langcode) && isset($languages[$user->preferred_langcode])) {
return $user->preferred_langcode;
}
// No language preference from the user.
return FALSE;
}
/**
* Identifies admin language from the user preferences.
*
* @param $languages
* An array of valid language objects.
*
* @return
* A valid language code on success, FALSE otherwise.
*/
function language_from_user_admin($languages) {
// User preference (only for authenticated users).
global $user;
if ($user->uid && !empty($user->preferred_admin_langcode) && isset($languages[$user->preferred_admin_langcode]) && path_is_admin(current_path())) {
return $user->preferred_admin_langcode;
}
// No language preference from the user or not on an admin path.
return FALSE;
}
/**
* Identify language from a request/session parameter.
*
* @param $languages
* An array of valid language objects.
*
* @return
* A valid language code on success, FALSE otherwise.
*/
function language_from_session($languages) {
$param = variable_get('language_negotiation_session_param', 'language');
// Request parameter: we need to update the session parameter only if we have
// an authenticated user.
if (isset($_GET[$param]) && isset($languages[$langcode = $_GET[$param]])) {
global $user;
if ($user->uid) {
$_SESSION[$param] = $langcode;
}
return $langcode;
}
// Session parameter.
if (isset($_SESSION[$param])) {
return $_SESSION[$param];
}
return FALSE;
}
/**
* Identify language via URL prefix or domain.
*
* @param $languages
* An array of valid language objects.
*
* @param $request
* The HttpRequest object representing the current request.
*
* @return
* A valid language code on success, FALSE otherwise.
*/
function language_from_url($languages, $request) {
$language_url = FALSE;
if (!language_negotiation_method_enabled(LANGUAGE_NEGOTIATION_URL)) {
return $language_url;
}
switch (variable_get('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX)) {
case LANGUAGE_NEGOTIATION_URL_PREFIX:
$current_path = $request->attributes->get('system_path');
if (!isset($current_path)) {
$current_path = trim($request->getPathInfo(), '/');
}
list($language, $path) = language_url_split_prefix($current_path, $languages);
// Store the correct system path, i.e. minus the path prefix, in the
// request.
$request->attributes->set('system_path', $path);
if ($language !== FALSE) {
$language_url = $language->langcode;
}
break;
case LANGUAGE_NEGOTIATION_URL_DOMAIN:
// Get only the host, not the port.
$http_host= $_SERVER['HTTP_HOST'];
if (strpos($http_host, ':') !== FALSE) {
$http_host_tmp = explode(':', $http_host);
$http_host = current($http_host_tmp);
}
$domains = language_negotiation_url_domains();
foreach ($languages as $language) {
// Skip the check if the language doesn't have a domain.
if (!empty($domains[$language->langcode])) {
// Ensure that there is exactly one protocol in the URL when checking
// the hostname.
$host = 'http://' . str_replace(array('http://', 'https://'), '', $domains[$language->langcode]);
$host = parse_url($host, PHP_URL_HOST);
if ($http_host == $host) {
$language_url = $language->langcode;
break;
}
}
}
break;
}
return $language_url;
}
/**
* Determines the language to be assigned to URLs when none is detected.
*
* The language negotiation process has a fallback chain that ends with the
* default language negotiation method. Each built-in language type has a
* separate initialization:
* - Interface language, which is the only configurable one, always gets a valid
* value. If no request-specific language is detected, the default language
* will be used.
* - Content language merely inherits the interface language by default.
* - URL language is detected from the requested URL and will be used to rewrite
* URLs appearing in the page being rendered. If no language can be detected,
* there are two possibilities:
* - If the default language has no configured path prefix or domain, then the
* default language is used. This guarantees that (missing) URL prefixes are
* preserved when navigating through the site.
* - If the default language has a configured path prefix or domain, a
* requested URL having an empty prefix or domain is an anomaly that must be
* fixed. This is done by introducing a prefix or domain in the rendered
* page matching the detected interface language.
*
* @param $languages
* (optional) An array of valid language objects. This is passed by
* language_negotiation_method_invoke() to every language method callback,
* but it is not actually needed here. Defaults to NULL.
*
* @param $request
* (optional) The HttpRequest object representing the current request.
*
* @param $language_type
* (optional) The language type to fall back to. Defaults to the interface
* language.
*
* @return
* A valid language code.
*/
function language_url_fallback($language = NULL, $request = NULL, $language_type = LANGUAGE_TYPE_INTERFACE) {
$default = language_default();
$prefix = (variable_get('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX) == LANGUAGE_NEGOTIATION_URL_PREFIX);
// If the default language is not configured to convey language information,
// a missing URL language information indicates that URL language should be
// the default one, otherwise we fall back to an already detected language.
$domains = language_negotiation_url_domains();
$prefixes = language_negotiation_url_prefixes();
if (($prefix && empty($prefixes[$default->langcode])) || (!$prefix && empty($domains[$default->langcode]))) {
return $default->langcode;
}
else {
$langcode = language($language_type)->langcode;
return $langcode;
}
}
/**
* Return links for the URL language switcher block.
*
* Translation links may be provided by other modules.
*/
function language_switcher_url($type, $path) {
$languages = language_list();
$links = array();
foreach ($languages as $language) {
$links[$language->langcode] = array(
'href' => $path,
'title' => $language->name,
'language' => $language,
'attributes' => array('class' => array('language-link')),
);
}
return $links;
}
/**
* Return the session language switcher block.
*/
function language_switcher_session($type, $path) {
$param = variable_get('language_negotiation_session_param', 'language');
$language_query = isset($_SESSION[$param]) ? $_SESSION[$param] : language($type)->langcode;
$languages = language_list();
$links = array();
$query = $_GET;
foreach ($languages as $language) {
$langcode = $language->langcode;
$links[$langcode] = array(
'href' => $path,
'title' => $language->name,
'attributes' => array('class' => array('language-link')),
'query' => $query,
);
if ($language_query != $langcode) {
$links[$langcode]['query'][$param] = $langcode;
}
else {
$links[$langcode]['attributes']['class'][] = ' session-active';
}
}
return $links;
}
/**
* Rewrite URLs for the URL language negotiation method.
*/
function language_url_rewrite_url(&$path, &$options) {
static $drupal_static_fast;
if (!isset($drupal_static_fast)) {
$drupal_static_fast['languages'] = &drupal_static(__FUNCTION__);
}
$languages = &$drupal_static_fast['languages'];
if (!isset($languages)) {
$languages = language_list();
$languages = array_flip(array_keys($languages));
}
// Language can be passed as an option, or we go for current URL language.
if (!isset($options['language'])) {
$language_url = language(LANGUAGE_TYPE_URL);
$options['language'] = $language_url;
}
// We allow only enabled languages here.
elseif (is_object($options['language']) && !isset($languages[$options['language']->langcode])) {
unset($options['language']);
return;
}
if (isset($options['language'])) {
switch (variable_get('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX)) {
case LANGUAGE_NEGOTIATION_URL_DOMAIN:
$domains = language_negotiation_url_domains();
if (is_object($options['language']) && !empty($domains[$options['language']->langcode])) {
global $is_https;
// Save the original base URL. If it contains a port, we need to
// retain it below.
if (!empty($options['base_url'])) {
// The colon in the URL scheme messes up the port checking below.
$normalized_base_url = str_replace(array('https://', 'http://'), '', $options['base_url']);
}
// Ask for an absolute URL with our modified base URL.
$url_scheme = ($is_https) ? 'https://' : 'http://';
$options['absolute'] = TRUE;
$options['base_url'] = $url_scheme . $domains[$options['language']->langcode];
// In case either the original base URL or the HTTP host contains a
// port, retain it.
$http_host = $_SERVER['HTTP_HOST'];
if (isset($normalized_base_url) && strpos($normalized_base_url, ':') !== FALSE) {
list($host, $port) = explode(':', $normalized_base_url);
$options['base_url'] .= ':' . $port;
}
elseif (strpos($http_host, ':') !== FALSE) {
list($host, $port) = explode(':', $http_host);
$options['base_url'] .= ':' . $port;
}
if (isset($options['https']) && variable_get('https', FALSE)) {
if ($options['https'] === TRUE) {
$options['base_url'] = str_replace('http://', 'https://', $options['base_url']);
}
elseif ($options['https'] === FALSE) {
$options['base_url'] = str_replace('https://', 'http://', $options['base_url']);
}
}
}
break;
case LANGUAGE_NEGOTIATION_URL_PREFIX:
$prefixes = language_negotiation_url_prefixes();
if (is_object($options['language']) &&!empty($prefixes[$options['language']->langcode])) {
$options['prefix'] = $prefixes[$options['language']->langcode] . '/';
}
break;
}
}
}
/**
* Reads language prefixes and uses the langcode if no prefix is set.
*/
function language_negotiation_url_prefixes() {
return variable_get('language_negotiation_url_prefixes', array());
}
/**
* Update the list of prefixes from the installed languages.
*/
function language_negotiation_url_prefixes_update() {
$prefixes = language_negotiation_url_prefixes();
foreach (language_list() as $language) {
// The prefix for this language should be updated if it's not assigned yet
// or the prefix is set to the empty string.
if (empty($prefixes[$language->langcode])) {
// For the default language, set the prefix to the empty string,
// otherwise use the langcode.
$prefixes[$language->langcode] = !empty($language->default) ? '' : $language->langcode;
}
// Otherwise we keep the configured prefix.
}
language_negotiation_url_prefixes_save($prefixes);
}
/**
* Saves language prefix settings.
*/
function language_negotiation_url_prefixes_save(array $prefixes) {
variable_set('language_negotiation_url_prefixes', $prefixes);
}
/**
* Reads language domains.
*/
function language_negotiation_url_domains() {
return variable_get('language_negotiation_url_domains', array());
}
/**
* Saves the language domain settings.
*/
function language_negotiation_url_domains_save(array $domains) {
variable_set('language_negotiation_url_domains', $domains);
}
/**
* Rewrite URLs for the Session language negotiation method.
*/
function language_url_rewrite_session(&$path, &$options) {
static $query_rewrite, $query_param, $query_value;
// The following values are not supposed to change during a single page
// request processing.
if (!isset($query_rewrite)) {
global $user;
if (!$user->uid) {
$languages = language_list();
$query_param = check_plain(variable_get('language_negotiation_session_param', 'language'));
$query_value = isset($_GET[$query_param]) ? check_plain($_GET[$query_param]) : NULL;
$query_rewrite = isset($languages[$query_value]) && language_negotiation_method_enabled(LANGUAGE_NEGOTIATION_SESSION);
}
else {
$query_rewrite = FALSE;
}
}
// If the user is anonymous, the user language negotiation method is enabled,
// and the corresponding option has been set, we must preserve any explicit
// user language preference even with cookies disabled.
if ($query_rewrite) {
if (is_string($options['query'])) {
$options['query'] = drupal_get_query_array($options['query']);
}
if (!isset($options['query'][$query_param])) {
$options['query'][$query_param] = $query_value;
}
}
}