/app/code/core/Mage/Adminhtml/controllers/Cms/PageController.php

<?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_Adminhtml
 * @copyright   Copyright (c) 2010 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */


/**
 * Cms manage pages controller
 *
 * @category   Mage
 * @package    Mage_Cms
 * @author      Magento Core Team <core@magentocommerce.com>
 */
class Mage_Adminhtml_Cms_PageController extends Mage_Adminhtml_Controller_Action
{

    /**
     * Init actions
     *
     * @return Mage_Adminhtml_Cms_PageController
     */
    protected function _initAction()
    {
        // load layout, set active menu and breadcrumbs
        $this->loadLayout()
            ->_setActiveMenu('cms/page')
            ->_addBreadcrumb(Mage::helper('cms')->__('CMS'), Mage::helper('cms')->__('CMS'))
            ->_addBreadcrumb(Mage::helper('cms')->__('Manage Pages'), Mage::helper('cms')->__('Manage Pages'))
        ;
        return $this;
    }

    /**
     * Index action
     */
    public function indexAction()
    {
        $this->_title($this->__('CMS'))
             ->_title($this->__('Pages'))
             ->_title($this->__('Manage Content'));

        $this->_initAction();
        $this->renderLayout();
    }

    /**
     * Create new CMS page
     */
    public function newAction()
    {
        // the same form is used to create and edit
        $this->_forward('edit');
    }

    /**
     * Edit CMS page
     */
    public function editAction()
    {
        $this->_title($this->__('CMS'))
             ->_title($this->__('Pages'))
             ->_title($this->__('Manage Content'));

        // 1. Get ID and create model
        $id = $this->getRequest()->getParam('page_id');
        $model = Mage::getModel('cms/page');

        // 2. Initial checking
        if ($id) {
            $model->load($id);
            if (! $model->getId()) {
                Mage::getSingleton('adminhtml/session')->addError(
                    Mage::helper('cms')->__('This page no longer exists.'));
                $this->_redirect('*/*/');
                return;
            }
        }

        $this->_title($model->getId() ? $model->getTitle() : $this->__('New Page'));

        // 3. Set entered data if was error when we do save
        $data = Mage::getSingleton('adminhtml/session')->getFormData(true);
        if (! empty($data)) {
            $model->setData($data);
        }

        // 4. Register model to use later in blocks
        Mage::register('cms_page', $model);

        // 5. Build edit form
        $this->_initAction()
            ->_addBreadcrumb(
                $id ? Mage::helper('cms')->__('Edit Page')
                    : Mage::helper('cms')->__('New Page'),
                $id ? Mage::helper('cms')->__('Edit Page')
                    : Mage::helper('cms')->__('New Page'));

        $this->renderLayout();
    }

    /**
     * Save action
     */
    public function saveAction()
    {
        // check if data sent
        if ($data = $this->getRequest()->getPost()) {
            $data = $this->_filterPostData($data);
            //init model and set data
            $model = Mage::getModel('cms/page');

            if ($id = $this->getRequest()->getParam('page_id')) {
                $model->load($id);
            }

            $model->setData($data);

            Mage::dispatchEvent('cms_page_prepare_save', array('page' => $model, 'request' => $this->getRequest()));

            //validating
            if (!$this->_validatePostData($data)) {
                $this->_redirect('*/*/edit', array('page_id' => $model->getId(), '_current' => true));
                return;
            }

            // try to save it
            try {
                // save the data
                $model->save();

                // display success message
                Mage::getSingleton('adminhtml/session')->addSuccess(
                    Mage::helper('cms')->__('The page has been saved.'));
                // clear previously saved data from session
                Mage::getSingleton('adminhtml/session')->setFormData(false);
                // check if 'Save and Continue'
                if ($this->getRequest()->getParam('back')) {
                    $this->_redirect('*/*/edit', array('page_id' => $model->getId(), '_current'=>true));
                    return;
                }
                // go to grid
                $this->_redirect('*/*/');
                return;

            } catch (Mage_Core_Exception $e) {
                $this->_getSession()->addError($e->getMessage());
            }
            catch (Exception $e) {
                $this->_getSession()->addException($e,
                    Mage::helper('cms')->__('An error occurred while saving the page.'));
            }

            $this->_getSession()->setFormData($data);
            $this->_redirect('*/*/edit', array('page_id' => $this->getRequest()->getParam('page_id')));
            return;
        }
        $this->_redirect('*/*/');
    }

    /**
     * Delete action
     */
    public function deleteAction()
    {
        // check if we know what should be deleted
        if ($id = $this->getRequest()->getParam('page_id')) {
            $title = "";
            try {
                // init model and delete
                $model = Mage::getModel('cms/page');
                $model->load($id);
                $title = $model->getTitle();
                $model->delete();
                // display success message
                Mage::getSingleton('adminhtml/session')->addSuccess(
                    Mage::helper('cms')->__('The page has been deleted.'));
                // go to grid
                Mage::dispatchEvent('adminhtml_cmspage_on_delete', array('title' => $title, 'status' => 'success'));
                $this->_redirect('*/*/');
                return;

            } catch (Exception $e) {
                Mage::dispatchEvent('adminhtml_cmspage_on_delete', array('title' => $title, 'status' => 'fail'));
                // display error message
                Mage::getSingleton('adminhtml/session')->addError($e->getMessage());
                // go back to edit form
                $this->_redirect('*/*/edit', array('page_id' => $id));
                return;
            }
        }
        // display error message
        Mage::getSingleton('adminhtml/session')->addError(Mage::helper('cms')->__('Unable to find a page to delete.'));
        // go to grid
        $this->_redirect('*/*/');
    }

    /**
     * Check the permission to run it
     *
     * @return boolean
     */
    protected function _isAllowed()
    {
        switch ($this->getRequest()->getActionName()) {
            case 'new':
            case 'save':
                return Mage::getSingleton('admin/session')->isAllowed('cms/page/save');
                break;
            case 'delete':
                return Mage::getSingleton('admin/session')->isAllowed('cms/page/delete');
                break;
            default:
                return Mage::getSingleton('admin/session')->isAllowed('cms/page');
                break;
        }
    }

    /**
     * Filtering posted data. Converting localized data if needed
     *
     * @param array
     * @return array
     */
    protected function _filterPostData($data)
    {
        $data = $this->_filterDates($data, array('custom_theme_from', 'custom_theme_to'));
        return $data;
    }

    /**
     * Validate post data
     *
     * @param array $data
     * @return bool     Return FALSE if someone item is invalid
     */
    protected function _validatePostData($data)
    {
        $errorNo = true;
        if (!empty($data['layout_update_xml']) || !empty($data['custom_layout_update_xml'])) {
            /** @var $validatorCustomLayout Mage_Adminhtml_Model_LayoutUpdate_Validator */
            $validatorCustomLayout = Mage::getModel('adminhtml/layoutUpdate_validator');
            if (!empty($data['layout_update_xml']) && !$validatorCustomLayout->isValid($data['layout_update_xml'])) {
                $errorNo = false;
            }
            if (!empty($data['custom_layout_update_xml'])
            && !$validatorCustomLayout->isValid($data['custom_layout_update_xml'])) {
                $errorNo = false;
            }
            foreach ($validatorCustomLayout->getMessages() as $message) {
                $this->_getSession()->addError($message);
            }
        }
        return $errorNo;
    }
}