Valid url check in form validation

[eluser]aidehua[/eluser]
Since I can't find it built in to the form_validation library, I've created a MY_form_validation library with a valid_url() function in it:

Code:

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class MY_form_validation extends CI_form_validation {

    function valid_url($str){

           $pattern = "/^(http|https|ftp):\/\/([A-Z0-9][A-Z0-9_-]*(?:\.[A-Z0-9][A-Z0-9_-]*)+):?(\d+)?\/?/i";
            if (!preg_match($pattern, $str))
            {
                return FALSE;
            }

            return TRUE;
    }

}

Which I call in my validation rules like this:

Code:

$this->load->helper('url');
$this->form_validation->set_rules('author_url', 'Website', 'trim|prep_url|valid_url|xss_clean');

NB the regex in the valid_url() function requires an http:// or https:// or ftp:// prefix. I've added prep_url to the validation rule to add http:// if it is required. That's why I've loaded the URL helper first.

As expected, when validation fails on the author_url field, CodeIgniter displays this message:

The Website field must contain a valid URL

Straight out of the form_validation_lang.php file. Weird that it never made it into the form_validation library.