<?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;

jimport('joomla.form.formrule');

/**
 * Form Rule class for the Joomla Framework.
 *
 * @package     Joomla.Platform
 * @subpackage  Form
 * @since       11.1
 */
class JFormRuleEquals extends JFormRule
{
    /**
     * Method to test if two values are equal. To use this rule, the form
     * XML needs a validate attribute of equals and a field attribute
     * that is equal to the field to test against.
     *
     * @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.
        $field  = (string) $element['field'];

        // Check that a validation field is set.
        if (!$field) {
            return new JException(JText::sprintf('JLIB_FORM_INVALID_FORM_RULE', get_class($this)));
        }

        // Check that a valid JForm object is given for retrieving the validation field value.
        if (!($form instanceof JForm)) {
            return new JException(JText::sprintf('JLIB_FORM_INVALID_FORM_OBJECT', get_class($this)));
        }

        // Test the two values against each other.
        if ($value == $input->get($field)) {
            return true;
        }

        return false;
    }
}