WB 2.08.x

<?php

/**

 *

 * @category        backend

 * @package         framework

 * @author          Ryan Djurovich (2004-2009), WebsiteBaker Project

 * @copyright       2009-2012, WebsiteBaker Org. e.V.

 * @link			http://www.websitebaker2.org/

 * @license         http://www.gnu.org/licenses/gpl.html

 * @platform        WebsiteBaker 2.8.x

 * @requirements    PHP 5.2.2 and higher

 * @version         $Id: class.admin.php 1808 2012-11-07 11:05:52Z Luisehahne $

 * @filesource		$HeadURL: svn://isteam.dynxs.de/wb-archiv/branches/2.8.x/wb/framework/class.admin.php $

 * @lastmodified    $Date: 2012-11-07 12:05:52 +0100 (Wed, 07 Nov 2012) $

 *

 */

/* -------------------------------------------------------- */

// Must include code to stop this file being accessed directly

if(!defined('WB_PATH')) {

	require_once(dirname(__FILE__).'/globalExceptionHandler.php');

	throw new IllegalFileException();

}

/* -------------------------------------------------------- */

// Load the other required class files if they are not already loaded

if(!class_exists('wb', false)){ include(WB_PATH.'/framework/class.wb.php'); }

// Get WB version

require_once(ADMIN_PATH.'/interface/version.php');

// Include EditArea wrapper functions

// require_once(WB_PATH . '/include/editarea/wb_wrapper_edit_area.php');

// require_once(WB_PATH . '/framework/SecureForm.php');

/**

 * admin

 *

 * @package

 * @copyright

 * @version 2012

 * @access public

 */

class admin extends wb {

	// Authenticate user then auto print the header

	/**

	 * admin::__construct()

	 *

	 * @param string $section_name

	 * @param string $section_permission

	 * @param bool $auto_header

	 * @param bool $auto_auth

	 * @return void

	 */

	public function __construct($section_name= '##skip##', $section_permission = 'start', $auto_header = true, $auto_auth = true)

	{

		parent::__construct(SecureForm::BACKEND);

    	if( $section_name != '##skip##' )

    	{

    		global $database, $MESSAGE, $TEXT;

    		// Specify the current applications name

    		$this->section_name = $section_name;

    		$this->section_permission = $section_permission;

    		$maintance = ( defined('SYSTEM_LOCKED') && (SYSTEM_LOCKED==true) ? true : false );

    		// Authenticate the user for this application

    		if( ($auto_auth == true) )

    		{

    			// First check if the user is logged-in

    			if($this->is_authenticated() == false)

    			{

    				header('Location: '.ADMIN_URL.'/login/index.php');

    				exit(0);

    			}

    			// Now check if they are allowed in this section

    			if($this->get_permission($section_permission) == false) {

//    				die($MESSAGE['ADMIN_INSUFFICIENT_PRIVELLIGES']);

                    $sErrorMsgFile = $this->correct_theme_source('ErrorMsgFile.htt');

            		if(file_exists($sErrorMsgFile))

            		{

                        $this->print_header();

                        $oTpl = new Template(dirname( $sErrorMsgFile ));

//                        $oTpl->debug = true;

                        $sBackLink = (isset($_SERVER['QUERY_STRING'])&& ($_SERVER['QUERY_STRING']!='')) ? $_SERVER['HTTP_REFERER'].'?'.$_SERVER['QUERY_STRING'] :  $_SERVER['HTTP_REFERER'];

            		    $oTpl->set_file( 'page', 'ErrorMsgFile.htt' );

            	 	    $oTpl->set_var( 'THEME_URL', THEME_URL );

            			$oTpl->set_var( 'PAGE_ICON', 'negative');

            			$oTpl->set_var( 'ERROR_TITLE', $MESSAGE['MEDIA_DIR_ACCESS_DENIED']);

            	 	    $oTpl->set_var( 'PAGE_TITLE', $MESSAGE['ADMIN_INSUFFICIENT_PRIVELLIGES'] );

            	 	    $oTpl->set_var( 'BACK_LINK', $sBackLink );

            	 	    $oTpl->set_var( 'TEXT_BACK', $TEXT['BACK'] );

                		$output = $oTpl->finish($oTpl->parse('output', 'page'));

        			}

        			throw new ErrorMsgException($output);

                }

    		}

			if( ($maintance==true) || $this->get_session('USER_ID')!= 1 )

			{

           	//  check for show maintenance screen and terminate if needed

        		$this->ShowMaintainScreen('locked');

            }

    		// Check if the backend language is also the selected language. If not, send headers again.

    		$sql  = 'SELECT `language` FROM `'.TABLE_PREFIX.'users` ';

    		$sql .= 'WHERE `user_id`='.(int)$this->get_user_id();

    		$get_user_language = @$database->query($sql);

    		$user_language = ($get_user_language) ? $get_user_language->fetchRow() : '';

    		// prevent infinite loop if language file is not XX.php (e.g. DE_du.php)

    		$user_language = substr($user_language[0],0,2);

    		// obtain the admin folder (e.g. /admin)

    		$admin_folder = str_replace(WB_PATH, '', ADMIN_PATH);

    		if( (LANGUAGE != $user_language) && file_exists(WB_PATH .'/languages/' .$user_language .'.php')

    			&& strpos($_SERVER['SCRIPT_NAME'],$admin_folder.'/') !== false) {

    			// check if page_id is set

    			$page_id_url = (isset($_GET['page_id'])) ? '&page_id=' .(int) $_GET['page_id'] : '';

    			$section_id_url = (isset($_GET['section_id'])) ? '&section_id=' .(int) $_GET['section_id'] : '';

    			 //  check if there is an query-string

    			if(isset($_SERVER['QUERY_STRING']) && $_SERVER['QUERY_STRING'] != '') {

    				header('Location: '.$_SERVER['SCRIPT_NAME'] .'?lang='.$user_language .$page_id_url .$section_id_url.'&'.$_SERVER['QUERY_STRING']);

    			} else {

    				header('Location: '.$_SERVER['SCRIPT_NAME'] .'?lang='.$user_language .$page_id_url .$section_id_url);

    			}

    			exit();

    		}

    		// Auto header code

    		if($auto_header == true) {

    			$this->print_header();

    		}

    	}

	}

	// Print the admin header

	/**

	 *

	 * @param string $body_tags

	 * @return void

	 */

	function print_header($body_tags = '')

	{

		// Get vars from the language file

		global $MENU, $MESSAGE, $TEXT;

		// Connect to database and get website title

		global $database;

		// $GLOBALS['FTAN'] = $this->getFTAN();

		$this->createFTAN();

		$sql = 'SELECT `value` FROM `'.TABLE_PREFIX.'settings` WHERE `name`=\'website_title\'';

		$get_title = $database->query($sql);

		$title = $get_title->fetchRow();

		// Setup template object, parse vars to it, then parse it

		$header_template = new Template(dirname($this->correct_theme_source('header.htt')) );

		$header_template->set_file('page', 'header.htt');

		$header_template->set_block('page', 'header_block', 'header');

		if(defined('DEFAULT_CHARSET')) {

			$charset=DEFAULT_CHARSET;

		} else {

			$charset='utf-8';

		}

		// work out the URL for the 'View menu' link in the WB backend

		// if the page_id is set, show this page otherwise show the root directory of WB

		$view_url = WB_URL;

		if(isset($_GET['page_id'])) {

			// extract page link from the database

			$sql  = 'SELECT `link` FROM `'.TABLE_PREFIX.'pages` ';

			$sql .= 'WHERE `page_id`='.intval($_GET['page_id']);

			$result = @$database->query($sql);

			$row = @$result->fetchRow();

			if($row) $view_url .= PAGES_DIRECTORY .$row['link']. PAGE_EXTENSION;

		}

        $HelpUrl = ((strtolower(LANGUAGE)!='de') ? '/en/help.php' : '/de/hilfe.php');

		$sServerAdress = isset($_SERVER['SERVER_ADDR']) ? $_SERVER['SERVER_ADDR'] : '127.0.0.1';

		$header_template->set_var(	array(

							'SECTION_FORGOT' => $MENU['FORGOT'],

							'SECTION_NAME' => $MENU['LOGIN'],

							'BODY_TAGS' => $body_tags,

							'WEBSITE_TITLE' => ($title['value']),

							'TEXT_ADMINISTRATION' => $TEXT['ADMINISTRATION'],

							'CURRENT_USER' => $MESSAGE['START_CURRENT_USER'],

							'DISPLAY_NAME' => $this->get_display_name(),

							'CHARSET' => $charset,

							//'LANGUAGE' => strtolower(LANGUAGE),

							'LANGUAGE' => LANGUAGE,

							'VERSION' => VERSION,

							'SP' => (defined('SP') ? SP : ''),

							'REVISION' => REVISION,

							'SERVER_ADDR' => ((int)$this->get_user_id()==1 ? $sServerAdress : ''),

							'WB_URL' => WB_URL,

							'ADMIN_URL' => ADMIN_URL,

							'THEME_URL' => THEME_URL,

							'START_URL' => ADMIN_URL.'/index.php',

							'START_CLASS' => 'start',

							'TITLE_START' => $TEXT['READ_MORE'],

							'TITLE_VIEW' => $TEXT['WEBSITE'],

							'TITLE_HELP' => 'WebsiteBaker '.$MENU['HELP'],

							'URL_VIEW' => $view_url,

							'TITLE_LOGOUT' => $MENU['LOGIN'],

							'LOGIN_DISPLAY_HIDDEN' => !$this->is_authenticated() ? 'hidden' : '',

							'LOGIN_DISPLAY_NONE' => !$this->is_authenticated() ? 'none' : '',

							'LOGIN_LINK' => $_SERVER['SCRIPT_NAME'],

							'LOGIN_ICON' => 'login',

							'START_ICON' => 'blank',

							'URL_HELP' => 'http://www.websitebaker2.org'.$HelpUrl,

							'BACKEND_MODULE_CSS' => $this->register_backend_modfiles('css'),	// adds backend.css

							'BACKEND_MODULE_JS'  => $this->register_backend_modfiles('js')		// adds backend.js

						)

					);

		$header_template->set_block('header_block', 'maintenance_block', 'maintenance');

		if($this->get_user_id() == 1)

		{

			$sys_locked = (((int)(defined('SYSTEM_LOCKED') ? SYSTEM_LOCKED : 0)) == 1);

			$header_template->set_var('MAINTENANCE_MODE', ($sys_locked ? $TEXT['MAINTENANCE_OFF'] : $TEXT['MAINTENANCE_ON']));

			$header_template->set_var('MAINTENANCE_ICON', THEME_URL.'/images/'.($sys_locked ? 'lock' : 'unlock').'.png');

			$header_template->set_var('MAINTAINANCE_URL', ADMIN_URL.'/settings/locking.php');

			$header_template->parse('maintenance', 'maintenance_block', true);

		}else

		{

			$header_template->set_block('maintenance_block', '');

		}

		// Create the menu

        $UrlLang = ((strtolower(LANGUAGE)!='de') ? 'en' : strtolower(LANGUAGE));

		if(!$this->is_authenticated())

		{

    		$header_template->set_var('STYLE', 'login');

    		$menu = array(

//						array('http://www.websitebaker.org/', '_blank', 'WebsiteBaker Home', 'help', 0),

//						array($view_url, '_blank', $TEXT['FRONTEND'], '', 0),

//						array(ADMIN_URL.'/login/index.php', '', $MENU['LOGIN'], '', 0)

						);

		} else {

			$header_template->set_var('STYLE', 'start');

			$header_template->set_var(	array(

						'SECTION_NAME' => $MENU[strtoupper($this->section_name)],

						'TITLE_LOGOUT' => $MENU['LOGOUT'],

						'LOGIN_DISPLAY_NONE' => '',

						'START_ICON' => 'home',

						'LOGIN_ICON' => 'logout',

						'LOGIN_LINK' => ADMIN_URL.'/logout/index.php',

						'TITLE_START' => $MENU['START']

						)

					);

			// @array ( $url, $target, $title, $page_permission, $permission_required )

			$menu = array(

//					array(ADMIN_URL.'/index.php', '', $MENU['START'], 'start', 1 ),

					array(ADMIN_URL.'/pages/index.php', '', $MENU['PAGES'], 'pages', 1),

// 					array($view_url, '_blank', $MENU['FRONTEND'], 'pages', 1),

					array(ADMIN_URL.'/media/index.php', '', $MENU['MEDIA'], 'media', 1),

					array(ADMIN_URL.'/addons/index.php', '', $MENU['ADDONS'], 'addons', 1),

					array(ADMIN_URL.'/preferences/index.php', '', $MENU['PREFERENCES'], 'preferences', 1),

					array(ADMIN_URL.'/settings/index.php', '', $MENU['SETTINGS'], 'settings', 1),

					array(ADMIN_URL.'/admintools/index.php', '', $MENU['ADMINTOOLS'], 'admintools', 1),

					array(ADMIN_URL.'/access/index.php', '', $MENU['ACCESS'], 'access', 1),

//					array('http://addons.websitebaker2.org/', '', 'WB-Addons', 'preferences', 1),

//					array('http://template.websitebaker2.org/', '', 'WB-Template', 'preferences', 1),

//					array('http://www.websitebaker.org/', '_blank', 'WebsiteBaker Home', '', 0),

//					array(ADMIN_URL.'/logout/index.php', '', $MENU['LOGOUT'], '', 0)

					);

		}

		$header_template->set_block('header_block', 'linkBlock', 'link');

		foreach($menu AS $menu_item)

		{

			$link = $menu_item[0];

			$target = ($menu_item[1] == '') ? '_self' : $menu_item[1];

			$title = $menu_item[2];

			$permission_title = $menu_item[3];

			$required = $menu_item[4];

			$replace_old = array(ADMIN_URL, WB_URL, '/', 'index.php');

			if($required == false || ($this->is_authenticated() && $this->get_link_permission($permission_title)) )

			{

				$header_template->set_var('LINK', $link);

				$header_template->set_var('TARGET', $target);

				// If link is the current section apply a class name

				if($permission_title == strtolower($this->section_name)) {

					$header_template->set_var('CLASS', $menu_item[3] . ' current');

					$header_template->set_var('STYLE', $menu_item[3] );

				} else {

					$header_template->set_var('CLASS', $menu_item[3] );

				}

				$header_template->set_var('TITLE', $title);

				// Print link

				$header_template->parse('link', 'linkBlock', true);

			}

		}

		$header_template->parse('header', 'header_block', false);

		$header_template->pparse('output', 'page');

		unset($header_template);

	}

	// Print the admin footer

		function print_footer($activateJsAdmin = false) {

		global $database,$starttime,$iPhpDeclaredClasses;

		// include the required file for Javascript admin

		if($activateJsAdmin == true) {

			if(file_exists(WB_PATH.'/modules/jsadmin/jsadmin_backend_include.php')){

				@include_once(WB_PATH.'/modules/jsadmin/jsadmin_backend_include.php');

			}

		}

		// Setup template object, parse vars to it, then parse it

		$footer_template = new Template(dirname($this->correct_theme_source('footer.htt')));

		$footer_template->set_file('page', 'footer.htt');

		$footer_template->set_block('page', 'footer_block', 'header');

		$footer_template->set_var(array(

						'BACKEND_BODY_MODULE_JS' => $this->register_backend_modfiles_body('js'),

						'WB_URL' => WB_URL,

						'ADMIN_URL' => ADMIN_URL,

						'THEME_URL' => THEME_URL,

			 ) );

		$footer_template->set_block('footer_block', 'show_debug_block', 'show_debug');

		$bDebug = (defined('DEBUG') ? DEBUG : false);

		$bDevInfo = (defined('DEV_INFOS') && (DEV_INFOS == true) && (1 == $this->get_user_id()) ? true : false);

//         if( $debug && (1 == $this->get_user_id()))

        if( $bDevInfo )

		{

			$footer_template->set_var('MEMORY', number_format(memory_get_peak_usage(true), 0, ',', '.').' Byte' );

//			$footer_template->set_var('MEMORY', number_format(memory_get_usage(true), 0, ',', '.').' Byte' );

			$footer_template->set_var('QUERIES', $database->getQueryCount );

			// $footer_template->set_var('QUERIES', 'disabled' );

	        $included_files =  get_included_files();

			$footer_template->set_var('INCLUDES', sizeof($included_files) );

	        $included_classes =  get_declared_classes();

			$footer_template->set_var('CLASSES', sizeof($included_classes)-$iPhpDeclaredClasses );

			$sum_classes = 0;

			$sum_filesize = 0;

			$footer_template->set_block('show_debug_block', 'show_block_list', 'show_list');

			$footer_template->set_block('show_block_list', 'include_block_list', 'include_list');

			// $bDebug = true;  for testing

			foreach($included_files as $filename)

			{

				if(!is_readable($filename)) { continue; }

				if($bDebug)

				{

					$footer_template->set_var('INCLUDES_ARRAY', str_replace(WB_PATH, '',$filename) );

					$footer_template->set_var('FILESIZE', number_format(filesize($filename), 0, ',', '.').' Byte');

					$footer_template->parse('include_list', 'include_block_list', true);

				}

				$sum_filesize += filesize($filename);

			}

			$footer_template->parse('show_list', 'show_block_list', true);

			$endtime = array_sum(explode(" ",microtime()));

			$iEndTime = $endtime;

			$iStartTime = $starttime;

			if(!$bDebug)

			{

				$footer_template->parse('show_list', '');

				$footer_template->parse('include_list', '');

			}

			$footer_template->set_var('FILESIZE', ini_get('memory_limit'));

			$footer_template->set_var('TXT_SUM_FILESIZE', 'Summary size of included files: ');

			$footer_template->set_var('SUM_FILESIZE', number_format($sum_filesize, 0, ',', '.').' Byte');

			$footer_template->set_var('SUM_CLASSES', number_format($sum_classes, 0, ',', '.').' Byte');

			$footer_template->set_var('PAGE_LOAD_TIME', round($iEndTime-$iStartTime,3 ));

			$footer_template->set_var('DUMP_CLASSES', '<pre>'.var_export($included_classes,true).'</pre>');

			$footer_template->parse('show_debug', 'show_debug_block', true);

        } else {

			$footer_template->parse('show_debug', '');

			$footer_template->parse('show_list', '');

        }

		$footer_template->parse('header', 'footer_block', false);

		$footer_template->pparse('output', 'page');

		unset($footer_template);

	}

	// Return a system permission

	function get_permission($name, $type = 'system') {

		// Append to permission type

		$type .= '_permissions';

		// Check if we have a section to check for

		if($name == 'start') {

			return true;

		} else {

			// Set system permissions var

			$system_permissions = $this->get_session('SYSTEM_PERMISSIONS');

			// Set module permissions var

			$module_permissions = $this->get_session('MODULE_PERMISSIONS');

			// Set template permissions var

			$template_permissions = $this->get_session('TEMPLATE_PERMISSIONS');

			// Return true if system perm = 1

			if (isset($$type) && is_array($$type) && is_numeric(array_search($name, $$type))) {

				if($type == 'system_permissions') {

					return true;

				} else {

					return false;

				}

			} else {

				if($type == 'system_permissions') {

					return false;

				} else {

					return true;

				}

			}

		}

	}

 function get_user_details($user_id) {

  global $database;

  $retval = array('username'=>'unknown','display_name'=>'Unknown','email'=>'');

  $sql  = 'SELECT `username`,`display_name`,`email` ';

  $sql .= 'FROM `'.TABLE_PREFIX.'users` ';

  $sql .= 'WHERE `user_id`='.(int)$user_id;

  if( ($resUsers = $database->query($sql)) ) {

   if( ($recUser = $resUsers->fetchRow()) ) {

    $retval = $recUser;

   }

  }

  return $retval;

 }

    //

	function get_section_details( $section_id, $backLink = 'index.php' ) {

	global $database, $TEXT;

		$sql  = 'SELECT * FROM `'.TABLE_PREFIX.'sections` ';

		$sql .= 'WHERE `section_id`='.intval($section_id);

		if(($resSection = $database->query($sql))){

			if(!($recSection = $resSection->fetchRow())) {

				$this->print_header();

				$this->print_error($TEXT['SECTION'].' '.$TEXT['NOT_FOUND'], $backLink, true);

			}

			} else {

				$this->print_header();

				$this->print_error($database->get_error(), $backLink, true);

			}

		return $recSection;

	}

	function get_page_details( $page_id, $backLink = 'index.php' ) {

		global $database, $TEXT;

		$sql  = 'SELECT * FROM `'.TABLE_PREFIX.'pages` ';

		$sql .= 'WHERE `page_id`='.intval($page_id);

		if(($resPages = $database->query($sql))){

			if(!($recPage = $resPages->fetchRow())) {

			$this->print_header();

			$this->print_error($TEXT['PAGE'].' '.$TEXT['NOT_FOUND'], $backLink, true);

			}

		} else {

			$this->print_header();

			$this->print_error($database->get_error(), $backLink, true);

		}

		return $recPage;

	}

	function get_page_permission($page,$action='admin') {

		if($action != 'viewing') { $action = 'admin'; }

		$action_groups = $action.'_groups';

		$action_users  = $action.'_users';

		$groups = $users = '0';

		if(is_array($page)) {

			$groups = $page[$action_groups];

			$users  = $page[$action_users];

		} else {

			global $database;

			$sql  = 'SELECT `'.$action_groups.'`,`'.$action_users.'` ';

			$sql .= 'FROM `'.TABLE_PREFIX.'pages` ';

			$sql .= 'WHERE `page_id`='.(int)$page;

			if( ($res = $database->query($sql)) ) {

				if( ($rec = $res->fetchRow()) ) {

					$groups = $rec[$action_groups];

					$users  = $rec[$action_users];

				}

			}

		}

		return ($this->ami_group_member($groups) || $this->is_group_match($this->get_user_id(), $users));

	}

	// Returns a system permission for a menu link

	function get_link_permission($title) {

		$title = str_replace('_blank', '', $title);

		$title = strtolower($title);

		// Set system permissions var

		$system_permissions = $this->get_session('SYSTEM_PERMISSIONS');

		// Set module permissions var

		$module_permissions = $this->get_session('MODULE_PERMISSIONS');

		if($title == 'start') {

			return true;

		} else {

			// Return true if system perm = 1

			if(is_numeric(array_search($title, $system_permissions))) {

				return true;

			} else {

				return false;

			}

		}

	}

	// Function to add optional module Javascript or CSS stylesheets into the <body> section of the backend

	function register_backend_modfiles_body($file_id="js")

		{

		// sanity check of parameter passed to the function

		$file_id = strtolower($file_id);

		if($file_id !== "javascript" && $file_id !== "js")

		{

			return;

		}

		global $database;

        $body_links = "";

		// define default baselink and filename for optional module javascript and stylesheet files

		if($file_id == "js") {

			$base_link = '<script src="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend_body.js" type="text/javascript"></script>';

			$base_file = "backend_body.js";

		}

		// check if backend_body.js files needs to be included to the <body></body> section of the backend

		if(isset($_GET['tool']))

			{

			// check if displayed page contains a installed admin tool

			$sql  = 'SELECT * FROM `'.TABLE_PREFIX.'addons` ';

			$sql .= 'WHERE `type`=\'module\' AND `function`=\'tool\' AND `directory`=\''.addslashes($_GET['tool']).'\'';

			$result = $database->query($sql);

			if($result->numRows())

				{

				// check if admin tool directory contains a backend_body.js file to include

				$tool = $result->fetchRow();

				if(file_exists(WB_PATH ."/modules/" .$tool['directory'] ."/$base_file"))

				{

					// return link to the backend_body.js file

					return str_replace("{MODULE_DIRECTORY}", $tool['directory'], $base_link);

				}

			}

		} elseif(isset($_GET['page_id']) or isset($_POST['page_id']))

		{

			// check if displayed page in the backend contains a page module

			if (isset($_GET['page_id']))

			{

				$page_id = (int) addslashes($_GET['page_id']);

			} else {

				$page_id = (int) addslashes($_POST['page_id']);

			}

			// gather information for all models embedded on actual page

			$sql = 'SELECT `module` FROM `'.TABLE_PREFIX.'sections` WHERE `page_id`='.(int)$page_id;

			$query_modules = $database->query($sql);

			while($row = $query_modules->fetchRow()) {

				// check if page module directory contains a backend_body.js file

				if(file_exists(WB_PATH ."/modules/" .$row['module'] ."/$base_file")) {

					// create link with backend_body.js source for the current module

					$tmp_link = str_replace("{MODULE_DIRECTORY}", $row['module'], $base_link);

					// ensure that backend_body.js is only added once per module type

					if(strpos($body_links, $tmp_link) === false) {

						$body_links .= $tmp_link ."\n";

					}

				}

			}

			// write out links with all external module javascript/CSS files, remove last line feed

			return rtrim($body_links);

		}

	}

	// Function to add optional module Javascript or CSS stylesheets into the <head> section of the backend

	function register_backend_modfiles($file_id="css") {

		// sanity check of parameter passed to the function

		$file_id = strtolower($file_id);

		if($file_id !== "css" && $file_id !== "javascript" && $file_id !== "js") {

			return;

		}

		global $database;

		// define default baselink and filename for optional module javascript and stylesheet files

		$head_links = "";

		if($file_id == "css") {

      	$base_link = '<link href="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend.css"';

			$base_link.= ' rel="stylesheet" type="text/css" media="screen" />';

			$base_file = "backend.css";

		} else {

			$base_link = '<script src="'.WB_URL.'/modules/{MODULE_DIRECTORY}/backend.js" type="text/javascript"></script>';

			$base_file = "backend.js";

		}

		// check if backend.js or backend.css files needs to be included to the <head></head> section of the backend

		if(isset($_GET['tool'])) {

			// check if displayed page contains a installed admin tool

			$sql  = 'SELECT * FROM `'.TABLE_PREFIX.'addons` ';

			$sql .= 'WHERE `type`=\'module\' AND `function`=\'tool\' AND `directory`=\''.addslashes($_GET['tool']).'\'';

			$result = $database->query($sql);

			if($result->numRows()) {

				// check if admin tool directory contains a backend.js or backend.css file to include

				$tool = $result->fetchRow();

				if(file_exists(WB_PATH ."/modules/" .$tool['directory'] ."/$base_file")) {

        			// return link to the backend.js or backend.css file

					return str_replace("{MODULE_DIRECTORY}", $tool['directory'], $base_link);

				}

			}

		} elseif(isset($_GET['page_id']) || isset($_POST['page_id'])) {

			// check if displayed page in the backend contains a page module

			if (isset($_GET['page_id'])) {

				$page_id = (int)$_GET['page_id'];

			} else {

				$page_id = (int)$_POST['page_id'];

			}

    		// gather information for all models embedded on actual page

			$sql = 'SELECT `module` FROM `'.TABLE_PREFIX.'sections` WHERE `page_id`='.(int)$page_id;

			$query_modules = $database->query($sql);

    		while($row = $query_modules->fetchRow()) {

				// check if page module directory contains a backend.js or backend.css file

      		if(file_exists(WB_PATH ."/modules/" .$row['module'] ."/$base_file")) {

					// create link with backend.js or backend.css source for the current module

					$tmp_link = str_replace("{MODULE_DIRECTORY}", $row['module'], $base_link);

        			// ensure that backend.js or backend.css is only added once per module type

        			if(strpos($head_links, $tmp_link) === false) {

						$head_links .= $tmp_link ."\n";

					}

				}

    		}

    		// write out links with all external module javascript/CSS files, remove last line feed

			return rtrim($head_links);

		}

	}

}