accept-to-gettext.inc 6.08 KiB
<?php
/*
 * accept-to-gettext.inc -- convert information in 'Accept-*' headers to
 * gettext language identifiers.
 * Copyright (c) 2003, Wouter Verhelst <wouter@debian.org>
 * Copyright (c) 2012-2018, FusionDirectory
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 * 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 St, Fifth Floor, Boston, MA 02110-1301, USA.
 * Usage:
 *  $locale=al2gt(<array of supported languages/charsets in gettext syntax>,
 *                <MIME type of document>);
 *  setlocale('LC_ALL', $locale); // or 'LC_MESSAGES', or whatever...
 * Example:
 *  $langs=array('nl_BE.ISO-8859-15','nl_BE.UTF-8','en_US.UTF-8','en_GB.UTF-8');
 *  $locale=al2gt($langs, 'text/html');
 *  setlocale('LC_ALL', $locale);
 * Note that this will send out header information (to be
 * RFC2616-compliant), so it must be called before anything is sent to
 * the user.
 * Assumptions made:
 * * Charset encodings are written the same way as the Accept-Charset
 *   HTTP header specifies them (RFC2616), except that they're parsed
 *   case-insensitive.
 * * Country codes and language codes are the same in both gettext and
 *   the Accept-Language syntax (except for the case differences, which
 *   are dealt with easily). If not, some input may be ignored.
 * * The provided gettext-strings are fully qualified; i.e., no "en_US";
 *   always "en_US.ISO-8859-15" or "en_US.UTF-8", or whichever has been
 *   used. "en.ISO-8859-15" is OK, though.
 * * The language is more important than the charset; i.e., if the
 *   following is given:
 *   Accept-Language: nl-be, nl;q=0.8, en-us;q=0.5, en;q=0.3
 *   Accept-Charset: ISO-8859-15, utf-8;q=0.5
 *   And the supplied parameter contains (amongst others) nl_BE.UTF-8
 *   and nl.ISO-8859-15, then nl_BE.UTF-8 will be picked.
 * $Log: accept-to-gettext.inc,v $
 * Revision 1.1.1.1  2003/11/19 19:31:15  wouter
 * * moved to new CVS repo after death of the old
 * * Fixed code to apply a default to both Accept-Charset and
 *   Accept-Language if none of those headers are supplied; patch from
 *   Dominic Chambers <dominic@encasa.com>
 * Revision 1.2  2003/08/14 10:23:59  wouter
 * Removed little error in Content-Type header syntaxis.
 * Revision 2012/06/07 Côme BERNIGAUD
 * Rewrote a lot of things, use functions and PHP features in order to be more efficient and more readable
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/*! * \brief Parse a string like nl-be, nl;q=0.8, en-us;q=0.5, en;q=0.3 * into an array like array('nl-be'=>1,'nl'=>0.8,'en-us'=>0.5,'en'=>0.3) */ function parse_scores ($str) { $scores = []; $parts = preg_split('/,/', $str); foreach ($parts as $part) { $part = trim(strtolower($part)); if (preg_match("/(.*);q=(.*)/", $part, $matches)) { $scores[$matches[1]] = $matches[2]; } else { $scores[$part] = 1; } } return $scores; } /*! * \brief Compute the maximum value in scores array, between keys from testvals array. * example: max_scores(array('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5),array('a','d','f')) returns 4 * if no key from testvals is found, returns 0 */ function max_scores ($scores, $testvals) { $values = array_intersect_key($scores, array_flip($testvals)); if (empty($values)) { return 0; } else { return max($values); } } /*! * \brief Parse a lang in gettext format and returns lang, country and charset. * example: en_US.utf-8 will return ('en','us','utf-8') */ function parse_gettext_lang ($str) { if (preg_match("/^([^_]*)(_([^_]*))?\.(.*)$/", $str, $m)) { return [strtolower($m[1]), strtolower($m[3]), strtolower($m[4])]; } else { return FALSE; } } function al2gt ($gettextlangs) { /* Check if ACCEPT_LANGUAGE isset */ if (empty($_SERVER["HTTP_ACCEPT_LANGUAGE"])) { /* default to "everything is acceptable", as RFC2616 specifies */ $acceptLang = '*'; } else { $acceptLang = $_SERVER["HTTP_ACCEPT_LANGUAGE"]; } if (empty($_SERVER["HTTP_ACCEPT_CHARSET"])) { /* default to "everything is acceptable", as RFC2616 specifies */ $acceptChar = 'ISO-8859-1,*;q=0.5'; } else { $acceptChar = $_SERVER["HTTP_ACCEPT_CHARSET"]; } $lang_scores = parse_scores($acceptLang); $char_scores = parse_scores($acceptChar); /* RFC2616: ``If no "*" is present in an Accept-Charset field, then * all character sets not explicitly mentioned get a quality value of * 0, except for ISO-8859-1, which gets a quality value of 1 if not * explicitly mentioned.'' */
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if (!isset($char_scores['ISO-8859-1']) && !isset($char_scores['*'])) { $char_scores['ISO-8859-1'] = 1; } /* Loop through the available languages/encodings, and pick the one * with the highest score, excluding the ones with a charset the user * did not include. */ // The lang with the maximum score found $max_lang = NULL; // The lang score of this lang $max_l_score = 0; // The char score of this lang $max_c_score = 0; foreach ($gettextlangs as $gtlang) { if (!($infos = parse_gettext_lang($gtlang))) { continue; } list ($lang, $country, $char) = $infos; $lang_score = max_scores($lang_scores, [$lang,$lang.'-'.$country,'*']); $char_score = max_scores($char_scores, [$char,'*']); if ($char_score == 0) { // exclude charsets the user refuses continue; } // if lang scores are equals we compare char scores if (($lang_score > $max_l_score) || (($lang_score == $max_l_score) && ($char_score > $max_c_score))) { $max_l_score = $lang_score; $max_c_score = $char_score; $max_lang = $gtlang; } } if ($max_lang === NULL) { return NULL; } return $max_lang; }