<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_Widget
 * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * Widget Block Interface
 *
 * @category    Mage
 * @package     Mage_Widget
 * @author      Magento Core Team <core@magentocommerce.com>
 */
interface Mage_Widget_Block_Interface
{
    /**
     * Produce and return widget's html output
     *
     * @return string
     */
    public function toHtml();

    /**
     * Add data to the widget.
     * Retains previous data in the widget.
     *
     * @param array $arr
     * @return Mage_Widget_Block_Interface
     */
    public function addData(array $arr);

    /**
     * Overwrite data in the widget.
     *
     * $key can be string or array.
     * If $key is string, the attribute value will be overwritten by $value.
     * If $key is an array, it will overwrite all the data in the widget.
     *
     * @param string|array $key
     * @param mixed $value
     * @return Varien_Object
     */
    public function setData($key, $value = null);
}