SEO friendly urls for multi language site

Question

I have a site that I'm building out with php that will allow for multi language for content. One part of the site will have business listings. I have SEO friendly urls setup to view these listings, so for example I would have a business listing called "A bar down the street". The url would look like this:

/listing/a-bar-down-the-street

However lets say there is an Arabic version of this listing, then the name would look like this:

شريط أسفل الشارع

How would I make that into the same url format as the English version but in the language it is currently in? When I tried my function on the Arabic version that turns a string into a seo friendly url it comes back empty.

EDIT: To clarify further, all I'm looking for is a php function that allows me to turn any string into an SEO friendly url no matter what language the site is in.

EDIT PART 2 Below is the function Im using to rewrite the string to a SEO friendly url. Perhaps you can tell me what I need to add to make it language friendly?

    public function urlTitle($str,$separator = 'dash',$lowercase = TRUE)
    {

        if ($separator == 'dash')
        {

            $search     = '_';
            $replace    = '-';

        }else
        {

            $search     = '-';
            $replace    = '_';

        }

        $trans = array(
                        '&\#\d+?;'              => '',
                        '&\S+?;'                => '',
                        '\s+'                   => $replace,
                        '[^a-z0-9\-_]'          => '',
                        $replace.'+'            => $replace,
                        $replace.'$'            => $replace,
                        '^'.$replace            => $replace,
                        '\.+$'                  => ''
                        );

        $str = strip_tags($str);
        $str = preg_replace("#\/#ui",'-',$str);

        foreach ($trans AS $key => $val)
        {

            $str = preg_replace("#".$key."#ui", $val, $str);

        }

        if($lowercase === TRUE)
        {

            $str = mb_strtolower($str);

        }

        return trim(stripslashes($str));

    }

Answer 1

I have found similar discussion in an existing SO discussion. It seems that what you are requesting should be possible "out-of-the-box".

I would recommend looking into your webserver config to see what is the problem, there should not be a difference between seo-friendly English urls and any other url-encodable string.

What webserver are you running?

UPDATE I see that you are only accepting alphanumeric characters:

'[^a-z0-9\-_]'          => '',

I suspect that may filter out any non-a-z characters and cause the empty return. Or, alternatively, you can try to debug your function to see which of the replace condition causes your content to be wiped-out.

What you are encountering here is that URLs by default cannot contain any character, browsers in general use encoding to achieve nice-looking multi language URLs.

See example from link:

URLs are allowed only a certain set of english letter characters, which includes the numbers, dashes, slashes, and the question mark. All other characters have to be encoded, which applies to non-Latin domain names. If you go to فنادق.com, you will notice that some browsers will decode it and show you فنادق.com but some like Chrome will show you something like this http://www.xn--mgbq6cgr.com/.

Which means that you can no longer filter your post title and only allow url-valid characters, you need to encode the titles and hope that the browser will render them as you would like.

Another option would be to use trans-literation, possibly after detection of a browser which is known to not render the url-encoded special characters.