Automatically Link WordPress Keywords to Tag Archives

//Automatically add internal links to WordPress post keywords
//Automatically turn tags into internal links

$match_num_from = 1; // Number of times a tag must appear before adding a link

$match_num_to = 2; // Number of links to add for the same tag

add_filter('the_content','tag_link',1);

function tag_sort($a, $b){

if ( $a->name == $b->name ) return 0;

return ( strlen($a->name) > strlen($b->name) ) ? -1 : 1;

}

function tag_link($content){

global $match_num_from,$match_num_to;

$posttags = get_the_tags();

if ($posttags) {

usort($posttags, "tag_sort");

foreach($posttags as $tag) {

$link = get_tag_link($tag->term_id);

$keyword = $tag->name;

$cleankeyword = stripslashes($keyword);

$url = "<a href=\"$link\" title=\"".str_replace('%s',addcslashes($cleankeyword, '$'),__('View all posts in %s'))."\"";

$url .= ' target="_blank"';

$url .= ">".addcslashes($cleankeyword, '$')."";

$limit = rand($match_num_from,$match_num_to);

$content = preg_replace( '|(<a[^>]+>)(.*)('.$ex_word.')(.*)(</a[^>]*>)|U'.$case, '$1$2%&&&&&%$4$5', $content);

$content = preg_replace( '|(<img)(.*?)('.$ex_word.')(.*?)(>)|U'.$case, '$1$2%&&&&&%$4$5', $content);

$cleankeyword = preg_quote($cleankeyword,'\'');

$regEx = '\'(?!((<.*?)|(<a.*?)))('. $cleankeyword . ')(?!(([^<>]*?)>)|([^>]*?))\'s' . $case;

$content = preg_replace($regEx,$url,$content,$limit);

$content = str_replace( '%&&&&&%', stripslashes($ex_word), $content);

}

}

return $content;

}