check_language function - language settings are ignored

[CyberFoundry]

When the browser doesn't supply the HTTP_ACCEPT_LANGUAGE header, language setting are ignored and postfixadmin always defaults to the $CONF['default_language'] setting.

IMO the desired behavior should not be dependent on the presence of the HTTP_ACCEPT_LANGUAGE header. Eg:

`
function check_language ($use_post = 1) {
global $supported_languages; # from languages/languages.php

$lang = Config::read('default_language');

$lang_array = array();

if (safecookie('lang')) {
    array_unshift($lang_array, safecookie('lang')); # prefer language from cookie
}
if ( $use_post && safepost('lang')) {
    array_unshift($lang_array, safepost('lang')); # but prefer $_POST['lang'] even more
}
if(isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
    array_merge($lang_array,preg_split ('/(\s*,\s*)/', $_SERVER['HTTP_ACCEPT_LANGUAGE']));
}

for($i = 0; $i < count($lang_array); $i++) {
    $lang_next = $lang_array[$i];
    $lang_next = strtolower(trim($lang_next));
    $lang_next = preg_replace('/;.*$/', '', $lang_next); # remove things like ";q=0.8"
    if(array_key_exists($lang_next, $supported_languages)) {
        $lang = $lang_next;
        break;
    }
}

return $lang;

}
`

[cboltz]

Nice catch - you are right that the POST and COOKIE value should be honored even if HTTP_ACCEPT_LANGUAGE is not set.

I tend to do a slightly different fix - instead of making the function even more confusing with array_merge(), it should handle POST and COOKIE first.

--- a/functions.inc.php
+++ b/functions.inc.php
@@ -139,16 +139,22 @@ function _flash_string($type, $string) {
 function check_language ($use_post = 1) {
     global $supported_languages; # from languages/languages.php
 
+    if ( $use_post && safepost('lang')) {
+        if(array_key_exists(safepost('lang'), $supported_languages)) {
+            return safepost('lang'); # first preference: $_POST['lang']
+        }
+    }
+
+    if (safecookie('lang')) {
+        if(array_key_exists(safecookie('lang'), $supported_languages)) {
+            return safecookie('lang'); # second-best: $_COOKIE['lang']
+        }
+    }
+
     $lang = Config::read('default_language');
 
     if(isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
         $lang_array = preg_split ('/(\s*,\s*)/', $_SERVER['HTTP_ACCEPT_LANGUAGE']);
-        if (safecookie('lang')) {
-            array_unshift($lang_array, safecookie('lang')); # prefer language from cookie
-        }
-        if ( $use_post && safepost('lang')) {
-            array_unshift($lang_array, safepost('lang')); # but prefer $_POST['lang'] even more
-        }
 
         for($i = 0; $i < count($lang_array); $i++) {
             $lang_next = $lang_array[$i];

I gave this patch only minimal testing (which is also the reason why I didn't commit it yet), so feel free to test and report back ;-)

[CyberFoundry]

In the meantime I have replaced the function with my own version, that respects HTTP_ACCEPT_LANGUAGE priorities as well. I have also made some basic cleanup like the order of tests etc.

`
function check_language ($use_post = 1) {
global $supported_languages; # from languages/languages.php
$lang_array = array();
$lang = Config::read('default_language');

if ( $use_post && safepost('lang')) {
    $lang_array[strtolower(safepost('lang'))] = 1;
}
if (safecookie('lang')) {
    $lang_array[strtolower(safecookie('lang')] = 1;
}
if(!empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
    $langtags = explode(',',strtolower($_SERVER['HTTP_ACCEPT_LANGUAGE']));
    for($i = 0; $i < count($langtags); $i++ )  {
    	$langcode = NULL;
        $langpriority = NULL;
		$langdef = explode(';',$langtags[$i]);
		if (isset($langdef[0])) {
			$langcode = trim($langdef[0]);
		}
        if (isset($langdef[1])) {
			$langpriority = trim($langdef[1]);
		}
		if (!empty($langcode)) {
			$langcode = substr($langcode,0,2);
			if (ctype_alpha($langcode)) {
				$xpriority = 1;
				if (!empty($langpriority) && strpos($langpriority,'q=') === 0) {
					$q = (float)trim(substr($langpriority,2));
					if (is_numeric($q) && $q >= 0 && $q <= 1) {
                    	$xpriority = $q;
					}
				}
				if (!isset($lang_array[$langcode])) {
					$lang_array[$langcode] = $xpriority;
				}
				elseif ($lang_array[$langcode] < $xpriority) {
                	$lang_array[$langcode] = $xpriority;
				}
			}
		}
	}
}

if (count($lang_array) > 0) {
    $bestpriority  = -1;
    foreach ($lang_array as $langcode => $langpriority) {
		if (array_key_exists($langcode, $supported_languages)) {
			if ($bestpriority < $langpriority) {
				$lang = $langcode;
    			$bestpriority = $langpriority;
			}
		}
	}
}

return $lang;

}
`

[cboltz]

If $_POST['lang'] or $_COOKIE['lang'] is set, this means the user selected a language manually in the dropdown now ($_POST) or some days ago ($_COOKIE). Therefore $_POST and $_COOKIE should always win - if they contain a valid language, there's no need to check HTTP_ACCEPT_LANGUAGE.

Besides that - honoring the priorities is a nice addition, thanks!

It's clearly worth the additional CPU cycles, but it reminds me to
common.php: $language = check_language (); # TODO: storing the language only at login instead of calling check_language() on every page would save some processor cycles ;-)
;-) which should be doable by storing the language in the session.