bug 985: Factor out language handling into a separate class, also fix

language handling for Internet Explorer.

TODO:
- replace all uses of $_SESSION['_config']['language'] and
	$_SESSION['_config']['translations'] with the appropriate calls to the
	new class
- adjust character handling in the PDF generation routines
- probably more

Signed-off-by: Michael Tänzer <neo@nhng.de>

1 files changed, 331 insertions, 0 deletions

diff --git a/includes/lib/l10n.php b/includes/lib/l10n.php
new file mode 100644
index 0000000..386cece
--- /dev/null
+++ b/includes/lib/l10n.php
@@ -0,0 +1,331 @@
+<?php /*
+    LibreSSL - CAcert web application
+    Copyright (C) 2004-2011  CAcert Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; version 2 of the License.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+/**
+ * This class provides some functions for language handling
+ */
+class L10n {
+	/**
+	 * These are tranlations we currently support.
+	 * 
+	 * If another translation is added, it doesn't suffice to have gettext set
+	 * up, you also need to add it here, because it acts as a white list.
+	 * 
+	 * @var array("ISO-language code" => "native name of the language")
+	 */
+	public static $translations = array(
+				"ar" => "&#1575;&#1604;&#1593;&#1585;&#1576;&#1610;&#1577;",
+				"bg" => "&#1041;&#1098;&#1083;&#1075;&#1072;&#1088;&#1089;&#1082;&#1080;",
+				"cs" => "&#268;e&scaron;tina",
+				"da" => "Dansk",
+				"de" => "Deutsch",
+				"el" => "&Epsilon;&lambda;&lambda;&eta;&nu;&iota;&kappa;&#940;",
+				"en" => "English",
+				"es" => "Espa&#xf1;ol",
+				"fi" => "Suomi",
+				"fr" => "Fran&#xe7;ais",
+				"hu" => "Magyar",
+				"it" => "Italiano",
+				"ja" => "&#26085;&#26412;&#35486;",
+				"lv" => "Latvie&scaron;u",
+				"nl" => "Nederlands",
+				"pl" => "Polski",
+				"pt" => "Portugu&#xea;s",
+				"pt-br" => "Portugu&#xea;s Brasileiro",
+				"ru" => "&#x420;&#x443;&#x441;&#x441;&#x43a;&#x438;&#x439;",
+				"sv" => "Svenska",
+				"tr" => "T&#xfc;rk&#xe7;e",
+				"zh-cn" => "&#x4e2d;&#x6587;(&#x7b80;&#x4f53;)",
+				"zh-tw" => "&#x4e2d;&#x6587;(&#33274;&#28771;)",
+			);
+	
+	/**
+	 * setlocale needs a language + region code for whatever reason so here's
+	 * the mapping from a translation code to locales with the region that
+	 * seemed the most common for this language
+	 * 
+	 * You probably never need this. Use {@link set_translation()} to change the
+	 * language instead of manually calling setlocale().
+	 * 
+	 * @var array(string => string)
+	 */
+	private static $locales = array(
+				"ar" => "ar_JO",
+				"bg" => "bg_BG",
+				"cs" => "cs_CZ",
+				"da" => "da_DK",
+				"de" => "de_DE",
+				"el" => "el_GR",
+				"en" => "en_US",
+				"es" => "es_ES",
+				"fa" => "fa_IR",
+				"fi" => "fi_FI",
+				"fr" => "fr_FR",
+				"he" => "he_IL",
+				"hr" => "hr_HR",
+				"hu" => "hu_HU",
+				"id" => "id_ID",
+				"is" => "is_IS",
+				"it" => "it_IT",
+				"ja" => "ja_JP",
+				"ka" => "ka_GE",
+				"ko" => "ko_KR",
+				"lv" => "lv_LV",
+				"nb" => "nb_NO",
+				"nl" => "nl_NL",
+				"pl" => "pl_PL",
+				"pt" => "pt_PT",
+				"pt-br" => "pt_BR",
+				"ro" => "ro_RO",
+				"ru" => "ru_RU",
+				"sl" => "sl_SI",
+				"sv" => "sv_SE",
+				"th" => "th_TH",
+				"tr" => "tr_TR",
+				"uk" => "uk_UA",
+				"zh-cn" => "zh_CN",
+				"zh-tw" => "zh_TW",
+			);
+	
+	/**
+	 * Auto-detects the language that should be used and sets it. Only works for
+	 * HTTP, not in a command line script.
+	 * 
+	 * Priority:
+	 * <ol>
+	 * 	<li>explicit parameter "lang" passed in HTTP (e.g. via GET)</li>
+	 * 	<li>existing setting in the session (stick to the setting we had before)
+	 * 		</li>
+	 * 	<li>auto-detect via the HTTP Accept-Language header sent by the user
+	 * 		agent</li>
+	 * </ol>
+	 */
+	public static function detect_language() {
+		if (    (self::get_translation() != "")
+		            // already set in the session?
+		    &&
+		        !(array_key_exists("lang", $_REQUEST) &&
+		            trim($_REQUEST["lang"]) != "")
+		            // explicit parameter?
+		    )
+		{
+			if ( self::set_translation(self::get_translation()) ) {
+				return;
+			}
+		}
+		
+		
+		$languages = array();
+		
+		// parse Accept-Language header
+		if (array_key_exists('HTTP_ACCEPT_LANGUAGE', $_SERVER)) {
+			$bits = explode(",", strtolower(
+						str_replace(" ", "", $_SERVER['HTTP_ACCEPT_LANGUAGE'])
+					));
+			foreach($bits as $lang)
+			{
+				$b = explode(";", $lang);
+				if(count($b)>1 && substr($b[1], 0, 2) == "q=")
+					$c = floatval(substr($b[1], 2));
+				else
+					$c = 1;
+				
+				if ($c != 0)
+				{
+					$languages[trim($b[0])] = $c;
+				}
+			}
+		}
+		
+		// check if there is an explicit language given as parameter
+		if(array_key_exists("lang",$_REQUEST) && trim($_REQUEST["lang"]) != "")
+		{
+			// higher priority than those values in the header
+			$languages[strtolower(trim($_REQUEST["lang"]))] = 2.0;
+		}
+		
+		arsort($languages, SORT_NUMERIC);
+		
+		// this is used to be compatible with browsers like internet
+		// explorer which only provide the language code including the
+		// region not without. Also handles the fallback to English (qvalues
+		// may only have three digits after the .)
+		$fallbacks = array("en" => 0.0005);
+		
+		foreach($languages as $lang => $qvalue)
+		{
+			// ignore any non-conforming values (that's why we don't need to
+			// mysql_real_escape() or escapeshellarg(), but take care of
+			// the '*')
+			// spec: ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" )
+			if ( preg_match('/^(?:([a-zA-Z]{1,8})(?:-[a-zA-Z]{1,8})*|\*)$/',
+			                   $lang, $matches) !== 1 ) {
+				continue;
+			}
+			$lang_prefix = $matches[1]; // usually two-letter language code
+			$fallbacks[$lang_prefix] = $qvalue;
+			
+			$chosen_translation = "";
+			if ($lang === '*') {
+				// According to the standard '*' matches anything but any
+				// language explicitly specified. So in theory if there
+				// was an explicit mention of "en" with a lower priority
+				// this would be incorrect, but that's too much trouble.
+				$chosen_translation = "en";
+			} else {
+				$lang_length = strlen($lang);
+				foreach (self::$translations as $translation => $ignore)
+				{
+					// May match exactly or on every '-'
+					if ( $translation === $lang ||
+					         substr($translation, 0, $lang_length + 1)
+					             === $lang.'-'
+					    )
+					{
+						$chosen_translation = $translation;
+						break;
+					}
+				}
+			}
+			
+			if ($chosen_translation !== "")
+			{
+				if (self::set_translation($chosen_translation)) {
+					return;
+				}
+			}
+		}
+		
+		// No translation found yet => try the prefixes
+		arsort($fallbacks, SORT_NUMERIC);
+		foreach ($fallbacks as $lang => $qvalue) {
+			if (self::set_translation($chosen_translation)) {
+				return;
+			}
+		}
+		
+		// should not get here, as the fallback of "en" is provided and that
+		// should always work => log an error
+		trigger_error("L10n::detect_language(): could not set language",
+		        E_USER_WARNING);
+	}
+	
+	/**
+	 * Get the set translation
+	 * 
+	 * @return string a translation code or the empty string if not set
+	 */
+	public static function get_translation() {
+		if (array_key_exists('language', $_SESSION['_config'])) {
+			return $_SESSION['_config']['language'];
+		} else {
+			return "";
+		}
+	}
+	
+	/**
+	 * Set the translation to use.
+	 * 
+	 * @param string $translation_code    the translation code as specified in
+	 * 		the keys of {@link translations}
+	 * 
+	 * @return bool
+	 * 		<ul>
+	 * 		<li>true if the translation has been set successfully</li>
+	 * 		<li>false if the $translation_code was not contained in the white
+	 * 			list or could not be set for other reasons (e.g. setlocale()
+	 * 			failed because the locale has not been set up on the system -
+	 * 			details will be logged)</li>
+	 * 		</ul>
+	 */
+	public static function set_translation($translation_code) {
+		// check $translation_code against whitelist
+		if ( !array_key_exists($translation_code, self::$translations) ) {
+			// maybe it's a locale as previously used in the system? e.g. en_AU
+			if ( preg_match('/^([a-z][a-z])_([A-Z][A-Z])$/', $translation_code,
+			                    $matches) !== 1 ) {
+				return false;
+			}
+			
+			$lang_code = $matches[1];
+			$region_code = strtolower($matches[2]);
+			
+			if ( array_key_exists("${lang_code}-${region_code}",
+			                          self::$translations) ) {
+				$translation_code = "${lang_code}-${region_code}";
+			} elseif ( array_key_exists($lang_code, self::$translations) ) {
+				$translation_code = $lang_code;
+			} else {
+				return false;
+			}
+		}
+		
+		// map translation to locale
+		if ( !array_key_exists($translation_code, self::$locales) ) {
+			// weird. maybe you added a translation but haven't added a
+			// translation to locale mapping in self::locales?
+			trigger_error("L10n::set_translation(): could not map the ".
+				"translation $translation_code to a locale", E_USER_WARNING);
+			return false;
+		}
+		$locale = self::$locales[$translation_code];
+		
+		// set up locale
+		if ( !putenv("LANG=$locale") ) {
+			trigger_error("L10n::set_translation(): could not set the ".
+				"environment variable LANG to $locale", E_USER_WARNING);
+			return false;
+		}
+		if ( !setlocale(LC_ALL, $locale) ) {
+			trigger_error("L10n::set_translation(): could not setlocale() ".
+				"LC_ALL to $locale", E_USER_WARNING);
+			return false;
+		}
+		
+		// configure gettext
+		$domain = 'messages';
+		bindtextdomain($domain, $_SESSION['_config']['filepath']."/locale");
+		textdomain($domain);
+		
+		
+		// save the setting
+		$_SESSION['_config']['language'] = $translation_code;
+		
+		
+		// Set up the recode settings needed e.g. in PDF creation
+		$_SESSION['_config']['recode'] = "html..latin-1";
+		
+		if($translation_code === "zh-cn" || $translation_code === "zh-tw")
+		{
+			$_SESSION['_config']['recode'] = "html..gb2312";
+			
+		} else if($translation_code === "pl" || $translation_code === "hu") {
+			$_SESSION['_config']['recode'] = "html..ISO-8859-2";
+			
+		} else if($translation_code === "ja") {
+			$_SESSION['_config']['recode'] = "html..SHIFT-JIS";
+			
+		} else if($translation_code === "ru") {
+			$_SESSION['_config']['recode'] = "html..ISO-8859-5";
+			
+		} else if($translation_code == "lt") { // legacy, keep for reference
+			$_SESSION['_config']['recode'] = "html..ISO-8859-13";
+			
+		}
+	}
+}
\ No newline at end of file