This post is an introduction for experts in php and wordpress about filters used in xili-language.
The changes from wordpress’s version 2.7.x to 2.8, was an opportunity to verify filters and hooks used by xili-language plugin and for the plugin itself. And how to collect unique id of each filter (to, by instance, to temporary remove it or to cancel it…)
Two cases : the filter is already inside WordPress and the filter is created by the plugin itself.
In these two cases, the unique id of an added function differs when added inside a class as the class of xili_language. The unique id is currently the name of the function added in the filtering queue but if added during class instantiation, this unique id contains also as prefix the class name and a suffix (suffix different in WP 2.7.x and WP 2.8.x). So, since latest versions, we decide to store these filters id in class array var (idx[]).
First example : the filter is created by the plugin itself
by instance xili_language_list()
If the default plugin function detects that you have add you function to customize the language’s list, the function remove the filter (action) built by default in the class :
1935 1936 1937 1938 1939 1940 1941 | function xili_language_list($before = '<li>', $after ='</li>', $theoption='') { /* list of languages i.e. in sidebar */ global $xili_language; if ($xili_language->this_has_filter('xili_language_list')){ remove_filter('xili_language_list',$xili_language->idx['xili_language_list']); /*no default from class*/ } do_action('xili_language_list',$before,$after,$theoption); } |
Second example : the class add a filter
here to adapt category_link
This function is used in customization functions when we need to know « category link » without xili-language filtering (by instance as in wp_categories_list()).
1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 | /** * Replace get_category_link to bypass hook from xili_language * * @since 0.9.7.4 * @updated 1.0.1 * can be used in functions.php for special action needing permalink * @param category ID * @return the permalink of passed cat_id. */ function xiliml_get_category_link($catid = 0) { global $xili_language; if ($catid == 0) { global $wp_query; $catid = $wp_query->query_vars['cat']; } remove_filter('category_link', $xili_language->idx['xiliml_link_append_lang']); $catcur = get_category_link($catid); add_again_filter('category_link', 'xiliml_link_append_lang'); return $catcur; } |
It is possible because class memorize unique id when filter is added :
129 130 131 132 | add_filter('category_link', array(&$this,'xiliml_link_append_lang')); $filter = 'category_link'; $function = 'xiliml_link_append_lang'; $this->idx['xiliml_link_append_lang'] = _wp_filter_build_unique_id($filter, array (&$this, $function == '' ? $filter : $function), 10); /* unique id of this filter from object fixed 1.0.1 */ |
By offering API and hooks, wordpress opens wide world of customizations but needs rigourous coding…
In this coding extract, some lines about how, here on this website, the language’s list on sidebar is adapted via a function inside functions.php :
} elseif ($theoption == 'siderss') { if (is_category()) { $catcururl = xiliml_get_category_link(); $currenturl = $catcururl.'&'; //print_r(); $cat_ID = $wp_query->query_vars['cat']; $currentrss = get_bloginfo('siteurl').'?feed=rss2&cat='.$cat_ID; } else { // home $currenturl = get_bloginfo('siteurl').'/?'; $currentrss = get_bloginfo('siteurl').'/?feed=rss2'; } $listlanguages = get_terms_of_groups_lite (the_cur_langs_group_id(),TAXOLANGSGROUP,TAXONAME,'ASC'); foreach ($listlanguages as $language) { if ($language->slug != 'ar_ar' && $language->slug != 'ar_ma') { if ($before=='<li>') { if (the_curlang() == $language->slug) { $beforee = '<li class="current-cat" >'; } else { $beforee ='<li>'; } } $a .= $beforee ."<a href='".$currenturl.QUETAG."=".$language->slug."' title='".__('Posts selected',THEME_TEXTDOMAIN)." ".__('in '.$language->description,THEME_TEXTDOMAIN)."'>"." <img src='".get_bloginfo('template_directory')."/images/flags/".$language->slug.".png' alt='' /> ". __('in '.$language->description,THEME_TEXTDOMAIN) ."</a> <a href='".$currentrss.'&'.QUETAG."=".$language->slug."'><img src='".get_bloginfo('template_directory')."/images/rss.png' alt='rss'/></a>".$after; } } if (is_category()) { $currenturl = xiliml_get_category_link(); $a .= $before."<a href='".$currenturl."' title='".__('Posts of current category in all languages',THEME_TEXTDOMAIN)."' >"." <img src='".get_bloginfo('template_directory')."/images/flags/www.png' alt='' /> ".__('in all languages',THEME_TEXTDOMAIN)."</a> <a href='".$currentrss."'><img src='".get_bloginfo('template_directory')."/images/rss.png' alt='rss'/></a>".$after; } echo $a; } |
Hope that post will help and begin comments…
