chamilo-lms/index.php

<?php
/* For licensing terms, see /license.txt */

/**
 *	@package chamilo.main
 *	@author Patrick Cool <patrick.cool@UGent.be>, Ghent University, Refactoring
 *	@version $Id: index.php 22368 2009-07-24 23:25:57Z iflorespaz $
 *	@todo check the different @todos in this page and really do them
 *	@todo check if the news management works as expected
 */

// Only this script should have this constant defined. This is used to activate the javascript that
// gives the login name automatic focus in header.inc.html.
/** @todo Couldn't this be done using the $HtmlHeadXtra array? */
define('DOKEOS_HOMEPAGE', true);

$language_file = array('courses', 'index');

/* Flag forcing the 'current course' reset, as we're not inside a course anymore */
// Maybe we should change this into an api function? an example: Coursemanager::unset();
$cidReset = true;

/* 	Included libraries */

/** @todo make all the library files consistent, use filename.lib.php and not filename.lib.inc.php */
require_once 'main/inc/global.inc.php';

require_once api_get_path(LIBRARY_PATH).'course.lib.php';
require_once api_get_path(LIBRARY_PATH).'events.lib.inc.php';
require_once api_get_path(LIBRARY_PATH).'system_announcements.lib.php';
require_once api_get_path(LIBRARY_PATH).'groupmanager.lib.php';
require_once api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php';
require_once 'main/chat/chat_functions.lib.php';

require_once api_get_path(LIBRARY_PATH).'custompages.lib.php';

$loginFailed = isset($_GET['loginFailed']) ? true : isset($loginFailed);
$setting_show_also_closed_courses = api_get_setting('show_closed_courses') == 'true';

// the section (for the tabs)
$this_section = SECTION_CAMPUS;

/*	Action Handling */

/** @todo 	Wouldn't it make more sense if this would be done in local.inc.php so that local.inc.php become the only place where authentication is done?
 * 			by doing this you could logout from any page instead of only from index.php. From the moment there is a logout=true in the url you will be logged out
 * 			this can be usefull when you are on an open course and you need to log in to edit something and you immediately want to check how anonymous users
 * 			will see it.
 */
$my_user_id = api_get_user_id();

if (!empty($_GET['logout'])) {
	logout();
}

/* 	Table definitions */
$main_course_table 		= Database :: get_main_table(TABLE_MAIN_COURSE);
$main_category_table 	= Database :: get_main_table(TABLE_MAIN_CATEGORY);
$track_login_table 		= Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);

/* 	Constants and CONFIGURATION parameters */
/** @todo these configuration settings should move to the dokeos config settings */
/** defines wether or not anonymous visitors can see a list of the courses on the Dokeos homepage that are open to the world */
$_setting['display_courses_to_anonymous_users'] = 'true';

/** @todo remove this piece of code because this is not used */
if (isset($_user['user_id'])) {
	$nameTools = api_get_setting('siteName');
}

/* 		LOGIN  	*/

/**
 * @todo This piece of code should probably move to local.inc.php where the actual login / logout procedure is handled.
 * @todo consider removing this piece of code because does nothing.
 */
if (isset($_GET['submitAuth']) && $_GET['submitAuth'] == 1) {
	// nice lie!!!
	echo 'Attempted breakin - sysadmins notified.';
	session_destroy();
	die();
}

// Delete session neccesary for legal terms
if (api_get_setting('allow_terms_conditions') == 'true') {
	unset($_SESSION['update_term_and_condition']);
	unset($_SESSION['info_current_user']);
}

/**
 * @todo This piece of code should probably move to local.inc.php where the actual login procedure is handled.
 * @todo check if this code is used. I think this code is never executed because after clicking the submit button
 * 		 the code does the stuff in local.inc.php and then redirects to index.php or user_portal.php depending
 * 		 on api_get_setting('page_after_login')
 */

if (!empty($_POST['submitAuth'])) {
	// the user is already authenticated, we now find the last login of the user.
	if (isset ($_user['user_id'])) {
		$sql_last_login = "SELECT UNIX_TIMESTAMP(login_date)
								FROM $track_login_table
								WHERE login_user_id = '".$_user['user_id']."'
								ORDER BY login_date DESC LIMIT 1";
		$result_last_login = Database::query($sql_last_login);
		if (!$result_last_login) {
			if (Database::num_rows($result_last_login) > 0) {
				$user_last_login_datetime = Database::fetch_array($result_last_login);
				$user_last_login_datetime = $user_last_login_datetime[0];
				api_session_register('user_last_login_datetime');
			}
		}
		Database::free_result($result_last_login);

		//event_login();
		if (api_is_platform_admin()) {
			// decode all open event informations and fill the track_c_* tables
			include api_get_path(LIBRARY_PATH).'stats.lib.inc.php';
			decodeOpenInfos();
		}
	}

} // end login -- if ($_POST['submitAuth'])
else {
	// only if login form was not sent because if the form is sent the user was already on the page.
	event_open();
}
//checks user status and redirect him through custom page if setting is enabled

$user_status = (isset($_SESSION['_user']['user_id'])) ? $_user['status'] : null;

if ( $user_status == STUDENT && !api_get_setting('student_page_after_login') == '' ){
	$redirect_url = html_entity_decode(api_get_setting('student_page_after_login'));
	if ($redirect_url[0] == "/") {
		$redirect_url = substr(api_get_path(WEB_PATH), 0, -1).$redirect_url;
	}
    header('Location: '.$redirect_url);
      exit();
}
if ( $user_status == COURSEMANAGER && !api_get_setting('teacher_page_after_login') == '' ){
	$redirect_url = html_entity_decode(api_get_setting('teacher_page_after_login'));
	if ($redirect_url[0] == "/") {
		$redirect_url = substr(api_get_path(WEB_PATH), 0, -1).$redirect_url;
	}
    header('Location: '.$redirect_url);
      exit();
}
if ( $user_status == DRH && !api_get_setting('DRH_page_after_login') == '' ){
	$redirect_url = html_entity_decode(api_get_setting('DRH_page_after_login'));
	if ($redirect_url[0] == "/") {
		$redirect_url = substr(api_get_path(WEB_PATH), 0, -1).$redirect_url;
	}
    header('Location: '.$redirect_url);
      exit();
}
if ( $user_status == SESSIONADMIN && !api_get_setting('sessionadmin_page_after_login') == '' ){
	$redirect_url = html_entity_decode(api_get_setting('sessionadmin_page_after_login'));
	if ($redirect_url[0] == "/") {
		$redirect_url = substr(api_get_path(WEB_PATH), 0, -1).$redirect_url;
	}
    header('Location: '.$redirect_url);
      exit();
}


// Custom pages
if (api_get_setting('use_custom_pages') == 'true') {
	if (api_get_user_id()) {
		CustomPages::displayPage('index-logged');
	}
	else {
		CustomPages::displayPage('index-unlogged');
	}
}
// the header
Display::display_header(get_lang('Homepage'));

/*
	MAIN CODE
*/

echo '<div class="maincontent" id="content">';

// Plugins for loginpage_main AND campushomepage_main
if (!api_get_user_id()) {
	api_plugin('loginpage_main');
} else {
	api_plugin('campushomepage_main');
}

$home = 'home/';
if ($_configuration['multiple_access_urls']) {
	$access_url_id = api_get_current_access_url_id();
	if ($access_url_id != -1){
		$url_info = api_get_access_url($access_url_id);
		$url = api_remove_trailing_slash(preg_replace('/https?:\/\//i', '', $url_info['url']));
		$clean_url = replace_dangerous_char($url);
		$clean_url = str_replace('/', '-', $clean_url);
		$clean_url .= '/';
		$home_old = 'home/';
		$home = 'home/'.$clean_url;
	}
}

// Including the page for the news
$page_included = false;

if (!empty($_GET['include']) && preg_match('/^[a-zA-Z0-9_-]*\.html$/', $_GET['include'])) {
	$open = @(string)file_get_contents(api_get_path(SYS_PATH).$home.$_GET['include']);
	$open = api_to_system_encoding($open, api_detect_encoding(strip_tags($open)));
	echo $open;
	$page_included = true;
} else {

	if (!empty($_SESSION['user_language_choice'])) {
		$user_selected_language = $_SESSION['user_language_choice'];
	} elseif (!empty($_SESSION['_user']['language'])) {
		$user_selected_language = $_SESSION['_user']['language'];
	} else {
		$user_selected_language = api_get_setting('platformLanguage');
	}

	if (!file_exists($home.'home_news_'.$user_selected_language.'.html')) {
		if (file_exists($home.'home_top.html')) {
			$home_top_temp = file($home.'home_top.html');
		} else {
			$home_top_temp = file($home_old.'home_top.html');
		}
		$home_top_temp = implode('', $home_top_temp);
	} else {
		if (file_exists($home.'home_top_'.$user_selected_language.'.html')) {
			$home_top_temp = file_get_contents($home.'home_top_'.$user_selected_language.'.html');
		} else {
			$home_top_temp = file_get_contents($home.'home_top.html');
		}
	}
	if(trim($home_top_temp)=='') {
		$home_top_temp = get_lang('PortalHomepageDefaultIntroduction');
	}
    $open = str_replace('{rel_path}', api_get_path(REL_PATH), $home_top_temp);
    $open = api_to_system_encoding($open, api_detect_encoding(strip_tags($open)));
    echo $open;
}

// Display System announcements
$announcement = isset($_GET['announcement']) ? $_GET['announcement'] : -1;
$announcement = intval($announcement);

if (isset($_user['user_id'])) {
	$visibility = api_is_allowed_to_create_course() ? VISIBLE_TEACHER : VISIBLE_STUDENT;
	SystemAnnouncementManager :: display_announcements($visibility, $announcement);
} else {
	SystemAnnouncementManager :: display_announcements(VISIBLE_GUEST, $announcement);
}

// Display courses and category list
if (!$page_included) {
	if (api_get_setting('display_categories_on_homepage') == 'true') {
		echo '<div class="home_cats">';
		display_anonymous_course_list();
		echo '</div>';
	}
}
echo '</div>';

// Display right menu: language form, login section + useful weblinks
echo '<div class="menu" id="menu">';
display_anonymous_right_menu();
echo '</div>';

/*
	Footer
*/
Display :: display_footer();

/*
	Functions
*/

/**
 * This function handles the logout and is called whenever there is a $_GET['logout']
 *
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 */
function logout() {
	global $_configuration, $extAuthSource;
	// variable initialisation
	$query_string = '';

	if (!empty($_SESSION['user_language_choice'])) {
		$query_string = '?language='.$_SESSION['user_language_choice'];
	}

	// Database table definition
	$tbl_track_login = Database :: get_statistic_table(TABLE_STATISTIC_TRACK_E_LOGIN);

	// selecting the last login of the user
	$uid = intval($_GET['uid']);
	$sql_last_connection = "SELECT login_id, login_date FROM $tbl_track_login WHERE login_user_id='$uid' ORDER BY login_date DESC LIMIT 0,1";
	$q_last_connection = Database::query($sql_last_connection);
	if (Database::num_rows($q_last_connection) > 0) {
		$i_id_last_connection = Database::result($q_last_connection, 0, 'login_id');
	}

	if (!isset($_SESSION['login_as'])) {
		$current_date = date('Y-m-d H:i:s', time());
		$s_sql_update_logout_date = "UPDATE $tbl_track_login SET logout_date='".$current_date."' WHERE login_id='$i_id_last_connection'";
		Database::query($s_sql_update_logout_date);
	}
	LoginDelete($uid, $_configuration['statistics_database']); //from inc/lib/online.inc.php - removes the "online" status

	//the following code enables the use of an external logout function.
	//example: define a $extAuthSource['ldap']['logout']="file.php" in configuration.php
	// then a function called ldap_logout() inside that file
	// (using *authent_name*_logout as the function name) and the following code
	// will find and execute it
	$uinfo = api_get_user_info($uid);
	if (($uinfo['auth_source'] != PLATFORM_AUTH_SOURCE) && is_array($extAuthSource)) {
		if (is_array($extAuthSource[$uinfo['auth_source']])) {
			$subarray = $extAuthSource[$uinfo['auth_source']];
			if (!empty($subarray['logout']) && file_exists($subarray['logout'])) {
				include_once ($subarray['logout']);
				$logout_function = $uinfo['auth_source'].'_logout';
				if (function_exists($logout_function)) {
					$logout_function($uinfo);
				}
			}
		}
	}
	exit_of_chat($uid);
	api_session_destroy();
	header("Location: index.php$query_string");
	exit();
}

/**
 * This function checks if there are courses that are open to the world in the platform course categories (=faculties)
 *
 * @param unknown_type $category
 * @return boolean
 */
function category_has_open_courses($category) {
	global $setting_show_also_closed_courses;

	$user_identified = (api_get_user_id() > 0 && !api_is_anonymous());
	$main_course_table = Database :: get_main_table(TABLE_MAIN_COURSE);
	$sql_query = "SELECT * FROM $main_course_table WHERE category_code='$category'";
	$sql_result = Database::query($sql_query);
	while ($course = Database::fetch_array($sql_result)) {
		if (!$setting_show_also_closed_courses) {
			if ((api_get_user_id() > 0
				&& $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM)
				|| ($course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD)) {
				return true; //at least one open course
			}
		} else {
			if (isset($course['visibility'])) {
				return true; //at least one course (does not matter weither it's open or not because $setting_show_also_closed_courses = true
			}
		}
	}
	return false;
}

/**
 * Display create course link
 */
function display_create_course_link() {
	echo '<li><a href="main/create_course/add_course.php">'.get_lang('CourseCreate').'</a></li>';
}

/**
 * Display edit course list links
 */
function display_edit_course_list_links() {
	echo '<li><a href="main/auth/courses.php">'.get_lang('CourseManagement').'</a></li>';
}

/**
 * Display dashboard link
 */
function display_dashboard_link() {
	echo '<li><a href="main/dashboard/index.php">'.get_lang('Dashboard').'</a></li>';
}

/**
 * Displays the right-hand menu for anonymous users:
 * login form, useful links, help section
 * Warning: function defines globals
 * @version 1.0.1
 * @todo does $_plugins need to be global?
 */
function display_anonymous_right_menu() {
	global $loginFailed, $_plugins, $_user, $menu_navigation;

	$platformLanguage = api_get_setting('platformLanguage');
	$sys_path = api_get_path(SYS_PATH);

	if (!($_user['user_id']) || api_is_anonymous($_user['user_id']) ) { // Only display if the user isn't logged in
		api_display_language_form(true);
		echo '<br />';
		display_login_form();

		if ($loginFailed) {
			echo '<br />';
			handle_login_failed();
		}
		if (api_get_setting('allow_lostpassword') == 'true' || api_get_setting('allow_registration') == 'true') {
			echo '<div class="menusection"><span class="menusectioncaption">'.get_lang('MenuUser').'</span><ul class="menulist">';
			if (api_get_setting('allow_registration') != 'false') {
				echo '<li><a href="main/auth/inscription.php">'.get_lang('Reg').'</a></li>';
			}
			if (api_get_setting('allow_lostpassword') == 'true') {
				display_lost_password_info();
			}
			echo '</ul></div>';
		}
		if (api_number_of_plugins('loginpage_menu') > 0) {
			echo '<div class="note" style="background: none">';
			api_plugin('loginpage_menu');
			echo '</div>';
		}
	}


	// My Account section
	if (isset($_SESSION['_user']['user_id']) && $_SESSION['_user']['user_id'] != 0) {
		// tabs that are deactivated are added here

		$show_menu = false;
		$show_create_link = false;
		$show_course_link = false;

		$display_add_course_link = api_is_allowed_to_create_course() && ($_SESSION['studentview'] != 'studentenview');

		if ($display_add_course_link) {
			//display_create_course_link();
			$show_menu = true;
			$show_create_link = true;
		}

		if (api_is_platform_admin() || api_is_course_admin() || api_is_allowed_to_create_course()) {
			$show_menu = true;
			$show_course_link = true;
		} else {
			if (api_get_setting('allow_students_to_browse_courses') == 'true') {
				$show_menu = true;
				$show_course_link = true;
			}
		}

		if ($show_menu) {
			echo '<div class="menusection">';
			echo '<span class="menusectioncaption">'.get_lang('MenuUser').'</span>';
			echo '<ul class="menulist">';
			if ($show_create_link) {
				display_create_course_link();
			}
			if ($show_course_link) {
				if (!api_is_drh() && !api_is_session_admin()) {
					display_edit_course_list_links();
				} else {
					display_dashboard_link();
				}
			}
			echo '</ul></div>';
		}

		// Deleting the myprofile link
		if (api_get_setting('allow_social_tool') == 'true') {
			unset($menu_navigation['myprofile']);
		}

		if (!empty($menu_navigation)) {
			echo '<div class="menusection">';
			echo '<span class="menusectioncaption">'.get_lang('MainNavigation').'</span>';
			echo '<ul class="menulist">';
			foreach ($menu_navigation as $section => $navigation_info) {
				$current = $section == $GLOBALS['this_section'] ? ' id="current"' : '';
				echo '<li'.$current.'><a href="'.$navigation_info['url'].'" target="_self">'.$navigation_info['title'].'</a></li>', "\n";
			}
			echo '</ul></div>';
		}
	}

	// Help section
	/*** Hide right menu "general" and other parts on anonymous right menu *****/

	$user_selected_language = api_get_interface_language();
	global $home, $home_old;
	if (!isset($user_selected_language)) {
		$user_selected_language = $platformLanguage;
	}

	$home_menu = @(string)file_get_contents($sys_path.$home.'home_menu_'.$user_selected_language.'.html');
	if (empty($home_menu)) {
		$home_menu = @(string)file_get_contents($sys_path.$home_old.'home_menu_'.$user_selected_language.'.html');
	}
	if (empty($home_menu)) {
		$home_menu = @(string)file_get_contents($sys_path.$home.'home_menu.html');
	}
	if (empty($home_menu)) {
		$home_menu = @(string)file_get_contents($sys_path.$home_old.'home_menu.html');
	}
	if (!empty($home_menu)) {
		echo '<div class="menusection">', '<span class="menusectioncaption">'.get_lang('MenuGeneral').'</span>';
	 	echo '<ul class="menulist">';
	 	$home_menu = api_to_system_encoding($home_menu, api_detect_encoding(strip_tags($home_menu)));
	 	echo $home_menu;
		echo '</ul></div>';
	}

	if ($_user['user_id'] && api_number_of_plugins('campushomepage_menu') > 0) {
		echo '<div class="note" style="background: none">';
		api_plugin('campushomepage_menu');
		echo '</div>';
	}

	// includes for any files to be displayed below anonymous right menu

	$home_notice = @(string)file_get_contents($sys_path.$home.'home_notice_'.$user_selected_language.'.html');
	if (empty($home_notice)) {
		$home_notice = @(string)file_get_contents($sys_path.$home.'home_notice.html');
	}
	if (!empty($home_notice)) {
		echo '<div class="note">';
		$home_notice = api_to_system_encoding($home_notice, api_detect_encoding(strip_tags($home_notice)));
	 	echo $home_notice;
		echo '</div>';
	}
}

/**
*	Reacts on a failed login:
*	Displays an explanation with a link to the registration form.
*
*	@version 1.0.1
*/
function handle_login_failed() {
	if (!isset($_GET['error'])) {
		$message = get_lang('InvalidId');
		if (api_is_self_registration_allowed()) {
			$message = get_lang('InvalidForSelfRegistration');
		}
	} else {
		switch ($_GET['error']) {
			case '':
				$message = get_lang('InvalidId');
				if (api_is_self_registration_allowed()) {
					$message = get_lang('InvalidForSelfRegistration');
				}
				break;
			case 'account_expired':
				$message = get_lang('AccountExpired');
				break;
			case 'account_inactive':
				$message = get_lang('AccountInactive');
				break;
			case 'user_password_incorrect':
				$message = get_lang('InvalidId');
				break;
			case 'access_url_inactive':
				$message = get_lang('AccountURLInactive');
				break;
		}
	}
	echo '<div id="login_fail">'.$message.'</div>';
}

/**
*	Adds a form to let users login
*	@version 1.1
*/
function display_login_form() {
	$form = new FormValidator('formLogin');
	$form->addElement('text', 'login', get_lang('UserName'), array('size' => 17));
	$form->addElement('password', 'password', get_lang('Pass'), array('size' => 17));
	$form->addElement('style_submit_button','submitAuth', get_lang('LoginEnter'), array('class' => 'login'));
	$renderer =& $form->defaultRenderer();
	$renderer->setElementTemplate('<div><label>{label}</label></div><div>{element}</div>');
	$form->display();
	if (api_get_setting('openid_authentication') == 'true') {
		include_once 'main/auth/openid/login.php';
		echo '<div>'.openid_form().'</div>';
	}
}

/**
 * Displays a link to the lost password section
 */
function display_lost_password_info() {
	echo '<li><a href="main/auth/lostPassword.php">'.get_lang('LostPassword').'</a></li>';
}

/**
* Display list of courses in a category.
* (for anonymous users)
*
* @version 1.1
* @author Patrick Cool <patrick.cool@UGent.be>, Ghent University - refactoring and code cleaning
*/
function display_anonymous_course_list() {
	$ctok = $_SESSION['sec_token'];
	$stok = Security::get_token();

	//init
	$user_identified = (api_get_user_id() > 0 && !api_is_anonymous());
	$web_course_path = api_get_path(WEB_COURSE_PATH);
	$category = Database::escape_string($_GET['category']);
	global $setting_show_also_closed_courses;

	// Database table definitions
	$main_course_table 		= Database :: get_main_table(TABLE_MAIN_COURSE);
	$main_category_table 	= Database :: get_main_table(TABLE_MAIN_CATEGORY);

	$platformLanguage = api_get_setting('platformLanguage');

	//get list of courses in category $category
	$sql_get_course_list = "SELECT * FROM $main_course_table cours
								WHERE category_code = '".Database::escape_string($_GET['category'])."'
								ORDER BY title, UPPER(visual_code)";

	//showing only the courses of the current access_url_id
	global $_configuration;
	if ($_configuration['multiple_access_urls']) {
		$url_access_id = api_get_current_access_url_id();
		if ($url_access_id != -1) {
			$tbl_url_rel_course = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
			$sql_get_course_list = "SELECT * FROM $main_course_table as course INNER JOIN $tbl_url_rel_course as url_rel_course
					ON (url_rel_course.course_code=course.code)
					WHERE access_url_id = $url_access_id AND category_code = '".Database::escape_string($_GET['category'])."' ORDER BY title, UPPER(visual_code)";
		}
	}

	// Removed: AND cours.visibility='".COURSE_VISIBILITY_OPEN_WORLD."'
	$sql_result_courses = Database::query($sql_get_course_list);

	while ($course_result = Database::fetch_array($sql_result_courses)) {
		$course_list[] = $course_result;
	}

	$platform_visible_courses = '';
	// $setting_show_also_closed_courses
	if($user_identified) {
		if ($setting_show_also_closed_courses) {
			$platform_visible_courses = '';
		} else {
			$platform_visible_courses = "  AND (t3.visibility='".COURSE_VISIBILITY_OPEN_WORLD."' OR t3.visibility='".COURSE_VISIBILITY_OPEN_PLATFORM."' )";
		}
	} else {
		if ($setting_show_also_closed_courses) {
			$platform_visible_courses = '';
		} else {
			$platform_visible_courses = "  AND (t3.visibility='".COURSE_VISIBILITY_OPEN_WORLD."' )";
		}
	}
	$sqlGetSubCatList = "
				SELECT t1.name,t1.code,t1.parent_id,t1.children_count,COUNT(DISTINCT t3.code) AS nbCourse
				FROM $main_category_table t1
				LEFT JOIN $main_category_table t2 ON t1.code=t2.parent_id
				LEFT JOIN $main_course_table t3 ON (t3.category_code=t1.code $platform_visible_courses)
				WHERE t1.parent_id ". (empty ($category) ? "IS NULL" : "='$category'")."
				GROUP BY t1.name,t1.code,t1.parent_id,t1.children_count ORDER BY t1.tree_pos, t1.name";


	// Showing only the category of courses of the current access_url_id
	global $_configuration;
	if ($_configuration['multiple_access_urls']) {
		$url_access_id = api_get_current_access_url_id();
		if ($url_access_id != -1) {
			$tbl_url_rel_course = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_COURSE);
			$sqlGetSubCatList = "
				SELECT t1.name,t1.code,t1.parent_id,t1.children_count,COUNT(DISTINCT t3.code) AS nbCourse
				FROM $main_category_table t1
				LEFT JOIN $main_category_table t2 ON t1.code=t2.parent_id
				LEFT JOIN $main_course_table t3 ON (t3.category_code=t1.code $platform_visible_courses)
				INNER JOIN $tbl_url_rel_course as url_rel_course
					ON (url_rel_course.course_code=t3.code)
				WHERE access_url_id = $url_access_id AND t1.parent_id ".(empty($category) ? "IS NULL" : "='$category'")."
				GROUP BY t1.name,t1.code,t1.parent_id,t1.children_count ORDER BY t1.tree_pos, t1.name";
		}
	}

	$resCats = Database::query($sqlGetSubCatList);
	$thereIsSubCat = false;
	if (Database::num_rows($resCats) > 0) {
		$htmlListCat = '<h4 style="margin-top: 0px;">'.get_lang('CatList').'</h4><ul>';
		while ($catLine = Database::fetch_array($resCats)) {
			if ($catLine['code'] != $category) {

				$category_has_open_courses = category_has_open_courses($catLine['code']);
				if ($category_has_open_courses) {
					// The category contains courses accessible to anonymous visitors
					$htmlListCat .= '<li>';
					$htmlListCat .= '<a href="'.api_get_self().'?category='.$catLine['code'].'">'.$catLine['name'].'</a>';
					if (api_get_setting('show_number_of_courses') == 'true') {
						$htmlListCat .= ' ('.$catLine['nbCourse'].' '.get_lang('Courses').')';
					}
					$htmlListCat .= "</li>\n";
					$thereIsSubCat = true;
				} elseif ($catLine['children_count'] > 0) {
					// The category has children, subcategories
					$htmlListCat .= '<li>';
					$htmlListCat .= '<a href="'.api_get_self().'?category='.$catLine['code'].'">'.$catLine['name'].'</a>';
					$htmlListCat .= "</li>\n";
					$thereIsSubCat = true;
				}
				/************************************************************************
				 end changed code to eliminate the (0 courses) after empty categories
				 ************************************************************************/
				elseif (api_get_setting('show_empty_course_categories') == 'true') {
					$htmlListCat .= '<li>';
					$htmlListCat .= $catLine['name'];
					$htmlListCat .= "</li>\n";
					$thereIsSubCat = true;
				} //else don't set thereIsSubCat to true to avoid printing things if not requested
			} else {
				$htmlTitre = '<p>';
				if (api_get_setting('show_back_link_on_top_of_tree') == 'true') {
					$htmlTitre .= '<a href="'.api_get_self().'">&lt;&lt; '.get_lang('BackToHomePage').'</a>';
				}
				if (!is_null($catLine['parent_id']) || (api_get_setting('show_back_link_on_top_of_tree') != 'true' && !is_null($catLine['code']))) {
					$htmlTitre .= '<a href="'.api_get_self().'?category='.$catLine['parent_id'].'">&lt;&lt; '.get_lang('Up').'</a>';
				}
				$htmlTitre .= "</p>\n";
				if ($category != "" && !is_null($catLine['code'])) {
					$htmlTitre .= '<h3>'.$catLine['name']."</h3>\n";
				} else {
					$htmlTitre .= '<h3>'.get_lang('Categories')."</h3>\n";
				}
			}
		}
		$htmlListCat .= "</ul>\n";
	}
	echo $htmlTitre;
	if ($thereIsSubCat) {
		echo $htmlListCat;
	}
	while ($categoryName = Database::fetch_array($resCats)) {
		echo '<h3>', $categoryName['name'], "</h3>\n";
	}
	$numrows = Database::num_rows($sql_result_courses);
	$courses_list_string = '';
	$courses_shown = 0;
	if ($numrows > 0) {
		if ($thereIsSubCat) {
			$courses_list_string .= "<hr size=\"1\" noshade=\"noshade\">\n";
		}
		$courses_list_string .= '<h4 style="margin-top: 0px;">'.get_lang('CourseList')."</h4>\n<ul>\n";

		if (api_get_user_id()) {
			$courses_of_user = get_courses_of_user(api_get_user_id());
		}

		foreach ($course_list as $course) {
			// $setting_show_also_closed_courses

			if (!$setting_show_also_closed_courses) {
				// If we do not show the closed courses
				// we only show the courses that are open to the world (to everybody)
				// and the courses that are open to the platform (if the current user is a registered user
				if( ($user_identified && $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM) || ($course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD)) {
					$courses_shown++;
					$courses_list_string .= "<li>\n";
					$courses_list_string .= '<a href="'.$web_course_path.$course['directory'].'/">'.$course['title'].'</a><br />';
					if (api_get_setting('display_coursecode_in_courselist') == 'true') {
						$courses_list_string .= $course['visual_code'];
					}
					if (api_get_setting('display_coursecode_in_courselist') == 'true' && api_get_setting('display_teacher_in_courselist') == 'true') {
						$courses_list_string .= ' - ';
					}
					if (api_get_setting('display_teacher_in_courselist') == 'true') {
						$courses_list_string .= $course['tutor_name'];
					}
					if (api_get_setting('show_different_course_language') == 'true' && $course['course_language'] != api_get_setting('platformLanguage')) {
						$courses_list_string .= ' - '.$course['course_language'];
					}
					$courses_list_string .= "</li>\n";
				}
			}
			// We DO show the closed courses.
			// The course is accessible if (link to the course homepage)
			// 1. the course is open to the world (doesn't matter if the user is logged in or not): $course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD)
			// 2. the user is logged in and the course is open to the world or open to the platform: ($user_identified && $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM)
			// 3. the user is logged in and the user is subscribed to the course and the course visibility is not COURSE_VISIBILITY_CLOSED
			// 4. the user is logged in and the user is course admin of te course (regardless of the course visibility setting)
			// 5. the user is the platform admin api_is_platform_admin()
			//
			else {
				$courses_shown++;
				$courses_list_string .= "<li>\n";
				if ($course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD
						|| ($user_identified && $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM)
						|| ($user_identified && key_exists($course['code'], $courses_of_user) && $course['visibility'] != COURSE_VISIBILITY_CLOSED)
						|| $courses_of_user[$course['code']]['status'] == '1'
						|| api_is_platform_admin()) {
					$courses_list_string .= '<a href="'.$web_course_path.$course['directory'].'/">';
				}
				$courses_list_string .= $course['title'];
				if ($course['visibility'] == COURSE_VISIBILITY_OPEN_WORLD
						|| ($user_identified && $course['visibility'] == COURSE_VISIBILITY_OPEN_PLATFORM)
						|| ($user_identified && key_exists($course['code'], $courses_of_user) && $course['visibility'] != COURSE_VISIBILITY_CLOSED)
						|| $courses_of_user[$course['code']]['status'] == '1'
						|| api_is_platform_admin()) {
					$courses_list_string .= '</a><br />';
				}
				if (api_get_setting('display_coursecode_in_courselist') == 'true') {
					$courses_list_string .= ' '.$course['visual_code'];
				}
				if (api_get_setting('display_coursecode_in_courselist') == 'true' && api_get_setting('display_teacher_in_courselist') == 'true') {
					$courses_list_string .= ' - ';
				}
				if (api_get_setting('display_teacher_in_courselist') == 'true') {
					$courses_list_string .= $course['tutor_name'];
				}
				if (api_get_setting('show_different_course_language') == 'true' && $course['course_language'] != api_get_setting('platformLanguage')) {
					$courses_list_string .= ' - '.$course['course_language'];
				}
				if (api_get_setting('show_different_course_language') == 'true' && $course['course_language'] != api_get_setting('platformLanguage')) {
					$courses_list_string .= ' - '.$course['course_language'];
				}
				// We display a subscription link if
				// 1. it is allowed to register for the course and if the course is not already in the courselist of the user and if the user is identiefied
				// 2
				if ($user_identified && !key_exists($course['code'], $courses_of_user)) {
					if ($course['subscribe'] == '1') {
						$courses_list_string .= '<form action="main/auth/courses.php?action=subscribe&category='.Security::remove_XSS($_GET['category']).'" method="post">';
						$courses_list_string .= '<input type="hidden" name="sec_token" value="'.$stok.'">';
						$courses_list_string .= '<input type="hidden" name="subscribe" value="'.$course['code'].'" />';
						$courses_list_string .= '<input type="image" name="unsub" src="main/img/enroll.gif" alt="'.get_lang('Subscribe').'" />'.get_lang('Subscribe').'</form>';
					} else {
						$courses_list_string .= '<br />'.get_lang('SubscribingNotAllowed');
					}
				}
				$courses_list_string .= "</li>\n";
			}
		}
		$courses_list_string .= "</ul>\n";
	} else {
		// echo '<blockquote>', get_lang('_No_course_publicly_available'), "</blockquote>\n";
	}
	if ($courses_shown > 0) { //only display the list of courses and categories if there was more than
		// 0 courses visible to the world (we're in the anonymous list here)
		echo $courses_list_string;
	}
	if ($category != '') {
		echo '<p><a href="'.api_get_self().'"> ', Display :: return_icon('back.png', get_lang('BackToHomePage')), get_lang('BackToHomePage'), '</a></p>', "\n";
	}
}

/**
 * retrieves all the courses that the user has already subscribed to
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University, Belgium
 * @param int $user_id: the id of the user
 * @return array an array containing all the information of the courses of the given user
*/
function get_courses_of_user($user_id) {
	$table_course		= Database::get_main_table(TABLE_MAIN_COURSE);
	$table_course_user	= Database::get_main_table(TABLE_MAIN_COURSE_USER);
	// Secondly we select the courses that are in a category (user_course_cat <> 0) and sort these according to the sort of the category
	$user_id = intval($user_id);
	$sql_select_courses = "SELECT course.code k, course.visual_code  vc, course.subscribe subscr, course.unsubscribe unsubscr,
								course.title i, course.tutor_name t, course.db_name db, course.directory dir, course_rel_user.status status,
								course_rel_user.sort sort, course_rel_user.user_course_cat user_course_cat
								FROM    $table_course       course,
										$table_course_user  course_rel_user
								WHERE course.code = course_rel_user.course_code
								AND   course_rel_user.user_id = '".$user_id."'
								AND course_rel_user.relation_type<>".COURSE_RELATION_TYPE_RRHH."
								ORDER BY course_rel_user.sort ASC";
	$result = Database::query($sql_select_courses);
	$courses = array();
	while ($row = Database::fetch_array($result)) {
		// We only need the database name of the course
		$courses[$row['k']] = array('db' => $row['db'], 'code' => $row['k'], 'visual_code' => $row['vc'], 'title' => $row['i'], 'directory' => $row['dir'], 'status' => $row['status'], 'tutor' => $row['t'], 'subscribe' => $row['subscr'], 'unsubscribe' => $row['unsubscr'], 'sort' => $row['sort'], 'user_course_category' => $row['user_course_cat']);
	}
	return $courses;
}