<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Form
 *
 * @copyright   Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

// Detect if we have full UTF-8 and unicode PCRE support.
if (!defined('JCOMPAT_UNICODE_PROPERTIES')) {
    define('JCOMPAT_UNICODE_PROPERTIES', (bool) @preg_match('/\pL/u', 'a'));
}

/**
 * Form Rule class for the Joomla Framework.
 *
 * @package     Joomla.Platform
 * @subpackage  Form
 * @since       11.1
 */
class JFormRule
{
    /**
     * The regular expression to use in testing a form field value.
     *
     * @var     string
     * @since   11.1
     */
    protected $regex;

    /**
     * The regular expression modifiers to use when testing a form field value.
     *
     * @var     string
     * @since   11.1
     */
    protected $modifiers;

    /**
     * Method to test the value.
     *
     * @param   object  $element    The JXMLElement object representing the <field /> tag for the
     *                              form field object.
     * @param   mixed   $value      The form field value to validate.
     * @param   string  $group      The field name group control value. This acts as as an array
     *                              container for the field. For example if the field has name="foo"
     *                              and the group value is set to "bar" then the full field name
     *                              would end up being "bar[foo]".
     * @param   object  $input      An optional JRegistry object with the entire data set to validate
     *                              against the entire form.
     * @param   object  $form       The form object for which the field is being tested.
     *
     * @return  boolean True if the value is valid, false otherwise.
     * @since   11.1
     * @throws  JException on invalid rule.
     */
    public function test(& $element, $value, $group = null, & $input = null, & $form = null)
    {
        // Initialize variables.
        $name = (string) $element['name'];

        // Check for a valid regex.
        if (empty($this->regex)) {
            throw new JException(JText::sprintf('JLIB_FORM_INVALID_FORM_RULE', get_class($this)));
        }

        // Add unicode property support if available.
        if (JCOMPAT_UNICODE_PROPERTIES) {
            $this->modifiers = (strpos($this->modifiers, 'u') !== false) ? $this->modifiers : $this->modifiers.'u';
        }

        // Test the value against the regular expression.
        if (preg_match(chr(1).$this->regex.chr(1).$this->modifiers, $value)) {
            return true;
        }

        return false;
    }
}