<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Form
 *
 * @copyright   Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * Form Rule class for the Joomla Platform.
 *
 * @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   SimpleXMLElement  $element  The SimpleXMLElement 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   JRegistry         $input    An optional JRegistry object with the entire data set to validate against the entire form.
	 * @param   JForm             $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  InvalidArgumentException
	 * @throws  UnexpectedValueException
	 */
	public function test(SimpleXMLElement $element, $value, $group = null, JRegistry $input = null, JForm $form = null)
	{
		$field = (string) $element['field'];

		// Check that a validation field is set.
		if (!$field)
		{
			throw new UnexpectedValueException(sprintf('$field empty in %s::test', get_class($this)));
		}

		if (is_null($form))
		{
			throw new InvalidArgumentException(sprintf('The value for $form must not be null in %s', get_class($this)));
		}

		if (is_null($input))
		{
			throw new InvalidArgumentException(sprintf('The value for $input must not be null in %s', get_class($this)));
		}

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

		return false;
	}
}
