Links to single posts are 404ing after adding a rewrite rule [closed]

Question

In order to set up a URL rewrite rule for multiple taxonomy queries, I added this function and these hooks to the function.php file of a site's theme:

function add_custom_rewrite_rule(){
    add_rewrite_rule('(location|event)/(.+)/?$' , 'index.php?$matches[1]=$matches[2]', 'top');
}

add_action('init', 'add_custom_rewrite_rule');
add_action('init', 'flush_rewrite_rules');

It worked but now any link to a single post is broken. I tried removing the code I added and manually flushing permalinks in the admin, but links to single posts are still broken. Any ideas?

Update: I tried manually removing the "rewrite_rule" and "permalink_structure" rows from the "wp_options" table to see if that would force WordPress to update them when I changed the Permalink Settings in the admin, but the table didn't update when I did that.

I've also tried this call:

add_option("permalink_structure", "%year%/%monthnum%/%day%/%postname%/", "no");

And still saw no change in behavior or anything. Then I tried manually adding the row back to the database:

$get_wp_options_table = mysql_query("INSERT INTO wp_options (option_name, option_value, autoload) VALUES ('permalink_structure', '/%year%/%monthnum%/%day%/%postname%/', 'no')");

And the insert worked but again, no change in behavior whatsoever. Links to single posts still 404.

Answer 1

You need to call the flush_rewrite_rules() function within your add_custom_rewrite_rule() so it looks like:

function add_custom_rewrite_rule(){
    add_rewrite_rule('(location|event)/(.+)/?$' , 'index.php?$matches[1]=$matches[2]', 'top');

flush_rewrite_rules();
}

add_action('init', 'add_custom_rewrite_rule');

After some issues with lots of custom post types in 1 WordPress site I found the best solution is to flush when you activate your theme:

function flushRules(){
    global $pagenow, $wp_rewrite;

    if('themes.php' == $pagenow && isset( $_GET['activated'])){
        $wp_rewrite->flush_rules();
    }
}

add_action('load-themes.php', 'flushRules');