Rewrite rule for a query string

Question

I have a taxonomy search form and the link output is

http://localhost/wp/?cityid=16

But i want it to be rewrited as

http://localhost/wp/cityid/16

.htaccess

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wp/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wp/index.php [L]
</IfModule>

# END WordPress

It didn't work:

RewirteRule ^wp/cityid/([0-9]+)$ ?cityid=$1 [L]

It didnt work either (from wp codex):

add_action('generate_rewrite_rules', 'geotags_add_rewrite_rules');

    function geotags_add_rewrite_rules( $wp_rewrite ) 
    {
      $new_rules = array( 
         'cityid/(.+)' => 'index.php?cityid=' .
           $wp_rewrite->preg_index(1) );

      //​ Add the new rewrite rule into the top of the global rules array
      $wp_rewrite->rules = $new_rules + $wp_rewrite->rules;
    }

Any help please?

Answer 1

Try this code:

function geotags_add_rewrite_rules($wp_rewrite_rules) {
    global $wp_rewrite;

    $rule_key = '%cityid%';
    $url_pattern = '([^/]+)';
    $query_string = 'cityid=';

    $wp_rewrite->add_rewrite_tag($rule_key, $url_pattern, $query_string);

    $url_structure = $wp_rewrite->root . "cityid/$rule_key/";
    $rewrite_rules = $wp_rewrite->generate_rewrite_rules($url_structure);

    $wp_rewrite_rules = $rewrite_rules + $wp_rewrite_rules;
    return $wp_rewrite_rules;
}

add_filter('rewrite_rules_array', 'geotags_add_rewrite_rules');

function geotags_add_query_var($query_vars) {
    array_push($query_vars, 'cityid');
    return $query_vars;
}

add_filter('query_vars','geotags_add_query_var');

NOTE: Remember to save permalinks so your new rule is picked up by WP.