permalink error when modifying sanitize_title_with_dashes function

Question

By default, wordpress remove accents and weird characters to generate post_name in wp_posts table. This post_name is used when we change the permalink structure to /%postname%/ or some similar structures. In my language, i don't want to remove and replace many characters as it distorts the meaning.

I have change the sanitize_title_with_dashes function in wp-includes/formatting to:

function sanitize_title_with_dashes($title) {

$title = strip_tags($title);`
// Preserve escaped octets.
$title = preg_replace('|%([a-fA-F0-9][a-fA-F0-9])|', '---$1---', $title);
// Remove percent signs that are not part of an octet.
$title = str_replace('%', '', $title);
// Restore octets.
$title = preg_replace('|---([a-fA-F0-9][a-fA-F0-9])---|', '%$1', $title);

/* comment out this code block

if (seems_utf8($title)) {
    if (function_exists('mb_strtolower')) {
        $title = mb_strtolower($title, 'UTF-8');
    }
    $title = utf8_uri_encode($title, 200);
}

$title = strtolower($title);

*/

$title = preg_replace('/&.+?;/', '', $title); // kill entities
$title = str_replace('.', '-', $title);

// comment out $title = preg_replace('/[^%a-z0-9 _-]/', '', $title);

$title = preg_replace('/\s+/', '-', $title);
$title = preg_replace('|-+|', '-', $title);
$title = trim($title, '-');

return $title;

}

The post_name is correctly generated for all characters in my language, for example http://1.todaytravels.info in the latest post, the url is very good, but wordpress simply does not find the post (it says not found). I guess i need to change something in permalink structure so that WP query to the correct post.

Anyone know how to resolve this problem?

Thanks for any help!

Answer 1

Why did you want to alter the URI here? SEO optimization?

An URI has a limited number of allowed chars, defined in an RFC. That's the reason WordPress uses utf8_uri_encode to generate a permalink based on the posttitle.

You can find more information in this stackoverflow question: Which characters make a URL invalid?

EDIT

I've checked the wp_insert_post() function in wp-includes/post.php, which generates a new post in the database based on the submitted $_POST array. There you have a call to sanitize_post() on line 2487 and also a call to sanitize_title() on line 2548. You should check both functions.

Another option could be, that an attached filter to one of these sanitize functions are fired in the background. You could remove any filters with the function remove_all_filters()

For example:

remove_all_filters('sanitize_title', 99);

Answer 2

Non-ASCII characters in URLs have to be encoded. Use rawurlencode() to do that.

Example: a slug öüä has to be encoded as %C3%B6%C3%BC%C3%A4.
You can still enter öüä into the address bar, the browser will send the encoded URL to the server.
$_SERVER['REQUEST_URI'] will be 7%C3%B6%C3%BC%C3%A4, $_SERVER['REDIRECT_URL'] will be öüä.

Do not edit WordPress files, use a filter instead. You cannot run updates anymore otherwise.
In my plugin Germanix I hook into 'sanitize_title', take the second argument (the raw title) and change that. You should do the same.