On my site I have a multiple language to choose from for my users. This currently works with simple $_GET, redirects and cookies. But I want to upgrade this system to using language prefixed in my urls, so that they get indexed by Google. Since I already have something working, I would prefer to skip those bulky big plugins like WPML or qTranslate (and its descendants).
So I am now trying to do a plugin. On SO I have found a working code for plugin by user loushou (see his answer here: https://stackoverflow.com/a/20755049/3429689).
Now what this plugin does is adds rewrite tag %lang% and then replaces it inside multiple filters to the requested string (so example.com/en/post-name/ sets lang=en. It also updates all urls in the page to include the prefix (like in navigation menu and other places).
What I am now trying to accomplish is to remove the prefix for default page language, so that it would only show up if user selects any other language. So 'en' would be hidden from urls, but 'de' would show up. But here I have a problem. I managed to make WP not show the default prefix, but then suddenly pages and author pages stop working.
Here is the code:
<?php (__FILE__ == $_SERVER['SCRIPT_FILENAME']) ? die(header('Location: /')) : null;
/**
* Plugin Name: Loushou Language URLs
* Plugin URI: http://quadshot.com/
* Description: Adding the ability to have language support in your frontend urls.
* Version: 0.1-beta
* Author: Loushou
* Author URI: http://quadshot.com/
*/
class Clou_rewrite_takeover {
protected static $add_rules = array();
public static function pre_init() {
// debug
add_action('admin_footer-options-permalink.php', array(__CLASS__, 'qsart_rewrite_debug'));
// add rw tag
add_action('init', array(__CLASS__, 'add_directory_rewrite'));
// rw rule adds
add_filter(is_admin() ? 'setup_theme' : 'do_parse_request', array(__CLASS__, 'do_parse_request'), 0);
add_filter('post_rewrite_rules', array(__CLASS__, 'post_rewrite_rules'));
add_filter('date_rewrite_rules', array(__CLASS__, 'date_rewrite_rules'));
add_filter('root_rewrite_rules', array(__CLASS__, 'root_rewrite_rules'));
add_filter('comments_rewrite_rules', array(__CLASS__, 'comments_rewrite_rules'));
add_filter('search_rewrite_rules', array(__CLASS__, 'search_rewrite_rules'));
add_filter('author_rewrite_rules', array(__CLASS__, 'author_rewrite_rules'));
add_filter('page_rewrite_rules', array(__CLASS__, 'page_rewrite_rules'));
add_filter('rewrite_rules_array', array(__CLASS__, 'final_rules_correction'), PHP_INT_MAX, 1);
// query vars
add_filter('query_vars', array(__CLASS__, 'add_lang_query_var'), 10, 1);
add_filter('request', array(__CLASS__, 'default_language'), 9);
add_filter('locale', array(__CLASS__, 'set_language'));
// fix permalinks
$link_filters_needing_rewrite = array(
'post_link',
'post_type_link',
'page_link',
'attachment_link',
'search_link',
'post_type_archive_link',
'year_link',
'month_link',
'day_link',
'feed_link',
'author_link',
'term_link',
'category_feed_link',
'term_feed_link',
'taxonomy_feed_link',
'author_feed_link',
'search_feed_link',
'post_type_archive_feed_link',
);
add_filter('pre_post_link', array(__CLASS__, 'change_permalink_structure'), 10, 3);
foreach ($link_filters_needing_rewrite as $link_filter) {
add_filter($link_filter, array(__CLASS__, 'rewrite_lang_in_permalink'), 11, 3);
}
}
public static function do_parse_request($cur) {
self::get_page_permastruct();
self::get_author_permastruct();
self::correct_extras();
return $cur;
}
public static function get_supported_langs() {
return apply_filters('lou-get-supported-languages', array('en', 'de'));
}
public static function add_directory_rewrite() {
global $wp_rewrite;
$supported_languages = self::get_supported_langs();
// add_permastruct('lang', '%lang%', [ 'ep_mask' => EP_PERMALINK ] );
add_rewrite_tag('%lang%', '('.implode('|', $supported_languages).')?');
}
public static function unleadingslashit($str) {
return ltrim($str, '/');
}
public static function final_rules_correction($rules) {
global $wp_rewrite;
// print("<pre>".print_r($rules, true)."</pre>");
$new_rules = array();
$supported_languages = self::get_supported_langs();
$find = implode('|', $supported_languages);
$find_find = '#(?<!\()('.preg_quote($find, '#').')#';
$preg_node = str_replace('%%%', '(\d )', preg_quote($wp_rewrite->preg_index('%%%'), '#'));
foreach ($rules as $k => $v) {
if (preg_match($find_find, $k)) {
$nk = preg_replace($find_find, '('.$find.')', $k);
$parts = explode('?', $v);
$index = array_shift($parts);
$pv = implode('?', $parts);
// $pv = $v;
$pv = preg_replace_callback('#'.$preg_node.'#', function ($matches) use ($wp_rewrite) {
return $wp_rewrite->preg_index($matches[1] 1);
}, $pv);
$nv = $index.'?lang='.$wp_rewrite->preg_index(1).(!empty($pv) ? '&'.$pv : '');
$new_rules[$nk] = $nv;
} else {
$new_rules[$k] = $v;
}
}
// print("<pre>".print_r($new_rules, true)."</pre>");
return $new_rules;
}
public static function change_permalink_structure($struct) {
$struct = self::unleadingslashit($struct);
$struct = preg_replace('#^%lang%/?#', '', $struct);
// print("<pre>".print_r($struct, true)."</pre>");
return '/%lang%/'.$struct;
}
public static function extras_rewrite_rules($rules, $struct) {
global $wp_rewrite;
// var_dump($wp_rewrite);
// print("<pre>".print_r($wp_rewrite, true)."</pre>");
// var_dump($rules);
// var_dump($struct);
if(is_array($struct)) {
if ( count( $struct ) == 2 ) {
$new_rules = $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($struct[0]), $struct[1] );
} else {
$new_rules = $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($struct['struct']), $struct['ep_mask'], $struct['paged'], $struct['feed'], $struct['forcomments'], $struct['walk_dirs'], $struct['endpoints'] );
}
} else {
$new_rules = $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($struct) );
}
// print("<pre>".print_r($new_rules, true)."</pre>");
// print("<pre>".print_r($rules, true)."</pre>");
return $new_rules $rules;
}
public static function post_rewrite_rules($rules) {
global $wp_rewrite;
// hack to add code for extras type urls (usually created by other plugins)
$func = array(__CLASS__, 'extras_rewrite_rules');
foreach ($wp_rewrite->extra_permastructs as $type => $struct) {
// $filter = ($type == 'post_tag' ? 'tag' : $type).'_rewrite_rules';
$filter = $type.'_rewrite_rules';
add_filter($filter, function ($rules) use ($struct, $func) { return call_user_func_array($func, array($rules, $struct)); });
}
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->permalink_structure), EP_PERMALINK ) $rules;
}
public static function date_rewrite_rules($rules) {
global $wp_rewrite;
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->get_date_permastruct()), EP_DATE) $rules;
}
public static function root_rewrite_rules($rules) {
global $wp_rewrite;
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->get_date_permastruct()), EP_DATE) $rules;
}
public static function comments_rewrite_rules($rules) {
global $wp_rewrite;
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->root . $wp_rewrite->comments_base), EP_COMMENTS, false, true, true, false) $rules;
}
public static function search_rewrite_rules($rules) {
global $wp_rewrite;
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->get_search_permastruct()), EP_SEARCH) $rules;
}
public static function author_rewrite_rules($rules) {
global $wp_rewrite;
return $wp_rewrite->generate_rewrite_rules( self::change_permalink_structure($wp_rewrite->get_author_permastruct()), EP_AUTHORS) $rules;
}
public static function page_rewrite_rules($rules) {
global $wp_rewrite;
$page_structure = self::get_page_permastruct();
// $page_structure = $wp_rewrite->page_structure;
// $page_structure = $wp_rewrite->get_page_permastruct();
// $page_structure = self::change_permalink_structure($page_structure);
// print("<pre>".print_r($page_structure, true)."</pre>");
return $wp_rewrite->generate_rewrite_rules( $page_structure, EP_PAGES, true, true, false, false ) $rules;
}
protected static function get_page_permastruct() {
global $wp_rewrite;
if (empty($wp_rewrite->permalink_structure)) {
$wp_rewrite->page_structure = '';
return false;
}
$wp_rewrite->page_structure = self::change_permalink_structure($wp_rewrite->root . '%pagename%');
// print("<pre>".print_r($wp_rewrite, true)."</pre>");
return $wp_rewrite->page_structure;
}
protected static function get_author_permastruct() {
global $wp_rewrite;
if ( empty($wp_rewrite->permalink_structure) ) {
$wp_rewrite->author_structure = '';
return false;
}
$wp_rewrite->author_structure = self::change_permalink_structure($wp_rewrite->front . $wp_rewrite->author_base . '/%author%');
return $wp_rewrite->author_structure;
}
protected static function correct_extras() {
global $wp_rewrite;
foreach ($wp_rewrite->extra_permastructs as $k => $v)
$wp_rewrite->extra_permastructs[$k]['struct'] = self::change_permalink_structure($v['struct']);
}
public static function get_default_post_lang($post = 0) {
// return ( $lang = get_query_var('lang') ) ? $lang : 'en';
return ( $lang = get_query_var('lang') ) ? $lang : null;
}
public static function rewrite_lang_in_permalink($permalink, $post = 0, $leavename = false) {
// find the default post language via a function you have created to
// determine the default language url. this could be based on the current
// language the user has selected on the frontend, or based on the current
// url, or based on the post itself. it is up to you
$lang = self::get_default_post_lang($post);
// echo '<br />';
// echo $lang.' - '.$permalink;
// echo '<br />';
// once you have the default language, it is a simple search and replace
if(!is_null($lang)) {
return str_replace('%lang%', $lang, $permalink);
} else {
return str_replace('%lang%/', '', $permalink);
}
}
public static function add_lang_query_var($vars) {
// tell WP to expect the lang query_var, which you can then later use
$vars[] = 'lang';
// return the new list of query vars, which includes our lang param
return array_unique($vars);
}
public static function default_language($vars) {
if (array_diff( array_keys($vars), array('preview', 'page', 'paged', 'cpage') )) {
// $vars['lang'] = !empty($vars['lang']) ? $vars['lang'] : 'en';
$vars['lang'] = !empty($vars['lang']) ? $vars['lang'] : null;
// print("<pre>".print_r($vars, true)."</pre>");
// if(!empty($vars['lang']))
// $vars['lang'] = $vars['lang'];
}
return $vars;
}
public static function set_language() {
$lang = 'en';
$req_uri = explode('/', $_SERVER['REQUEST_URI']);
// strpos($_SERVER['REQUEST_URI'], '/ee/') === 0
if(in_array('de', $req_uri)) {
$lang = 'de';
}
$locale = self::convert_locale($lang);
return $locale;
}
public static function qsart_rewrite_debug() {
if (isset($_COOKIE['rwdebug']) && $_COOKIE['rwdebug'] == 1) {
global $wp_rewrite;
echo '<pre style="background-color:#ffffff; font-size:10px;">';
print_r($wp_rewrite->rules);
echo '</pre>';
}
}
}
if (defined('ABSPATH') && function_exists('add_action')) {
lou_rewrite_takeover::pre_init();
}
What I have noticed is that if I comment out line 70, do a rule flush and then enable this line, I get that pages without prefix start working, but then URL inside navigation and other places are not being changed (or rather are being changed to empty lang string).
Now if I leave the said line uncommented and do a flush, then if I try to visit page example.com/page-name/ - I get 404 page instead. What is interesting is that if I print out $vars var on line 328, I can see that WP is not setting "pagename" key, but instead sets "name", meaning that its trying to find a post instead of page, resulting in 404.
I would think this means that there is something wrong with rewrite rules. But checking them out reveals no obvious error, at least to me.
So I need help. Understanding that this code is from 2013, I would not hesitate to use any other suggested solution. Also if there is some kind of a small, very basic plugin that does this specific functionality, I would also use it. There also might be a way to get around using .htaccess, but I presume that get_query_vars would stop working.
CodePudding user response：
I manage to solve most of my problems by rewriting final_rules_correction() method and disabling filters for post/date/etc rewrite_rules.
What this does is rewrites all generated rules and adds a lang prefix regex to them and a lang var to the final link. It also allows for having an empty lang var if URL requested URL does not include lang var.
$prefixes = self::get_supported_langs();
$prefix_regexp = '(?:(' . implode( '|', $prefixes ) . ')/)?';
$new_rewrite_rules = array();
$match_pattern = '/\$matches\[(\d)\]/si';
foreach ( $rules as $rewrite_rule => $match ) {
$parts = explode('?', $match);
$index = array_shift($parts);
$pv = implode('?', $parts);
$pv = preg_replace_callback($match_pattern, function ($m) {
return sprintf('$matches[%d]', $m[1] 1);
}, $pv);
$nv = $index.'?lang='.$wp_rewrite->preg_index(1).(!empty($pv) ? '&'.$pv : '');
$new_rewrite_rules[$prefix_regexp . $rewrite_rule] = $nv;
}
The problem I have now is that URLs are not including lang prefix inside AJAX call. Thinking that I might have to pass lang prefix inside AJAX call and then rewrite permalinks for posts and other objects that I need to retrieve during AJAX call...
NOTE: this does not rewrite links in home_url and similar functions.