<?php
/**
 * 
 * Validates that a value is a URI (or URL).
 * 
 * @category Solar
 * 
 * @package Solar_Filter
 * 
 * @author Paul M. Jones <hide@address.com>
 * 
 * @license http://opensource.org/licenses/bsd-license.php BSD
 * 
 * @version $Id: ValidateUri.php 3732 2009-04-29 17:27:56Z pmjones $
 * 
 */
class Solar_Filter_ValidateUri extends Solar_Filter_Abstract
{
    /**
     * 
     * Validates the value as a URI.
     * 
     * The value must match a generic URI format; for example,
     * ``http://example.com``, ``mms://example.org``, and so on.
     * 
     * @param mixed $value The value to validate.
     * 
     * @return bool True if valid, false if not.
     * 
     */
    public function validateUri($value)
    {
        if ($this->_filter->validateBlank($value)) {
            return ! $this->_filter->getRequire();
        }
        
        // first, make sure there are no invalid chars, list from ext/filter
        $other = "$-_.+"        // safe
               . "!*'(),"       // extra
               . "{}|\\^~[]`"   // national
               . "<>#%\""       // punctuation
               . ";/?:@&=";     // reserved
        
        $valid = 'a-zA-Z0-9' . preg_quote($other, '/');
        $clean = preg_replace("/[^$valid]/", '', $value);
        if ($value != $clean) {
            return false;
        }
        
        // now make sure it parses as a URL with scheme and host
        $result = @parse_url($value);
        if (empty($result['scheme']) || trim($result['scheme']) == '' ||
            empty($result['host'])   || trim($result['host']) == '') {
            // need a scheme and host
            return false;
        } else {
            // looks ok
            return true;
        }
    }
}