subscribe_user.php

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

use \ExtraField as ExtraFieldModel;
use Chamilo\CoreBundle\Entity\ExtraField;

/**
* This script allows teachers to subscribe existing users
* to their course.
* @package chamilo.user
*/

require_once __DIR__.'/../inc/global.inc.php';
$current_course_tool  = TOOL_USER;

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

// notice for unauthorized people.
api_protect_course_script(true);

if (api_get_setting('allow_user_course_subscription_by_course_admin') === 'false') {
    if (!api_is_platform_admin()) {
        api_not_allowed(true);
    }
}

// Access restriction
if (!api_is_allowed_to_edit()) {
	 api_not_allowed(true);
}

$tool_name = get_lang("SubscribeUserToCourse");
$type = isset($_REQUEST['type']) ? intval($_REQUEST['type']) : STUDENT;
$keyword = isset($_REQUEST['keyword']) ? Security::remove_XSS($_REQUEST['keyword']) : null;

$courseInfo = api_get_course_info();

if ($type == COURSEMANAGER) {
	$tool_name = get_lang("SubscribeUserToCourseAsTeacher");
}

//extra entries in breadcrumb
$interbreadcrumb[] = array(
    "url" => "user.php?".api_get_cidreq(),
    "name" => get_lang("ToolUser")
);
if ($keyword) {
    $interbreadcrumb[] = array(
        "url" => "subscribe_user.php?type=".$type.'&'.api_get_cidreq(),
        "name" => $tool_name
    );
	$tool_name = get_lang('SearchResults');
}

$sessionId = api_get_session_id();
$list_register_user='';
$list_not_register_user='';

if (isset($_REQUEST['register'])) {
    $userInfo = api_get_user_info($_REQUEST['user_id']);
    $message = $userInfo['complete_name'].' '.get_lang('AddedToCourse');

    if ($type === COURSEMANAGER) {
        if (!empty($sessionId)) {
            $result_simple_sub = SessionManager::set_coach_to_course_session(
                $_REQUEST['user_id'],
                $sessionId,
                $courseInfo['real_id']
            );
            Display::addFlash(Display::return_message($message));
        } else {
            $result_simple_sub = CourseManager:: subscribe_user(
                $_REQUEST['user_id'],
                $courseInfo['code'],
                COURSEMANAGER
            );
            Display::addFlash(Display::return_message($message));
        }
    } else {
        $result_simple_sub = CourseManager:: subscribe_user(
            $_REQUEST['user_id'],
            $courseInfo['code']
        );
        Display::addFlash(Display::return_message($message));
    }
    header('Location:'.api_get_path(WEB_CODE_PATH).'user/user.php?'.api_get_cidreq().'&type='.$type);
    exit;
}

if (isset($_POST['action'])) {
    switch ($_POST['action']) {
        case 'subscribe':
            if (is_array($_POST['user'])) {
                foreach ($_POST['user'] as $index => $user_id) {
                    $userInfo = api_get_user_info($user_id);
                    if ($type === COURSEMANAGER) {
                        if (!empty($sessionId)) {
                            $is_suscribe[] = SessionManager::set_coach_to_course_session(
                                $user_id,
                                $sessionId,
                                $courseInfo['real_id']
                            );
                        } else {
                            $is_suscribe[] = CourseManager::subscribe_user(
                                $user_id,
                                $courseInfo['code'],
                                COURSEMANAGER
                            );
                        }
                    } else {
                        $is_suscribe[] = CourseManager::subscribe_user(
                            $user_id,
                            $courseInfo['code']
                        );
                    }
                    $message = $userInfo['complete_name'].' '.get_lang('AddedToCourse');
                    Display::addFlash(Display::return_message($message));
                }
            }

            header('Location:'.api_get_path(WEB_CODE_PATH).'user/user.php?'.api_get_cidreq().'&type='.$type);
            exit;
        break;
    }
}

$is_western_name_order = api_is_western_name_order();
$sort_by_first_name = api_sort_by_first_name();

// Build table
$table = new SortableTable(
	'subscribe_users',
	'get_number_of_users',
	'get_user_data',
	($is_western_name_order xor $sort_by_first_name) ? 3 : 2
);
$parameters['keyword'] = $keyword;
$parameters['type'] = $type;
$table->set_additional_parameters($parameters);
$col = 0;
$table->set_header($col++, '', false);
$table->set_header($col++, get_lang('OfficialCode'));
if (api_is_western_name_order()) {
    $table->set_header($col++, get_lang('FirstName'));
    $table->set_header($col++, get_lang('LastName'));
} else {
    $table->set_header($col++, get_lang('LastName'));
    $table->set_header($col++, get_lang('FirstName'));
}

if (api_get_setting('show_email_addresses') == 'true') {
    $table->set_header($col++, get_lang('Email'));
    $table->set_column_filter($col - 1, 'email_filter');
}
$table->set_header($col++, get_lang('Active'), false);
$table->set_column_filter($col -1, 'active_filter');
$table->set_header($col++, get_lang('Actions'), false);
$table->set_column_filter($col -1, 'reg_filter');
$table->set_form_actions(array ('subscribe' => get_lang('reg')), 'user');

if (!empty($_POST['keyword'])) {
    $keyword_name = Security::remove_XSS($_POST['keyword']);
    echo '<br/>'.get_lang('SearchResultsFor').' <span style="font-style: italic ;"> '.$keyword_name.' </span><br>';
}

Display :: display_header($tool_name, "User");

// Build search-form

switch ($type) {
    case STUDENT:
        $url = api_get_path(WEB_CODE_PATH).'user/user.php?'.api_get_cidreq().'';
        break;
    case COURSEMANAGER:
        $url = api_get_path(WEB_CODE_PATH).'user/user.php?'.api_get_cidreq().'&type='.COURSEMANAGER;
        break;
}
$actionsLeft = '';
$actionsLeft = Display::url(
    Display::return_icon('back.png', get_lang('Back'), '', ICON_SIZE_MEDIUM),
    $url
);

if (isset($_GET['subscribe_user_filter_value']) && !empty($_GET['subscribe_user_filter_value'])) {
    $actionsLeft .= '<a href="subscribe_user.php?type='.$type.'">'.
        Display::return_icon('clean_group.gif').' '.get_lang('ClearFilterResults').'</a>';
}
$extraForm = '';
if (api_get_setting('ProfilingFilterAddingUsers') === 'true') {
    $extraForm = display_extra_profile_fields_filter();
}

// Build search-form
$form = new FormValidator(
    'search_user',
    'get',
    api_get_self().'?'.api_get_cidreq(),
    '',
    null,
    FormValidator::LAYOUT_INLINE
);
$form->addText('keyword', '', false);
$form->addElement('hidden', 'type', $type);
$form->addElement('hidden', 'cidReq', api_get_course_id());
$form->addButtonSearch(get_lang('Search'));
echo Display::toolbarAction('toolbar-subscriber', [$actionsLeft.$extraForm, $form->returnForm()]);

$option = $type == COURSEMANAGER ? 2 : 1;
echo UserManager::getUserSubscriptionTab($option);

// Display table
$table->display();
Display::display_footer();

/*		SHOW LIST OF USERS  */

/**
 ** Get the users to display on the current page.
 */
function get_number_of_users()
{
	// Database table definition
	$user_table = Database::get_main_table(TABLE_MAIN_USER);
	$course_user_table = Database::get_main_table(TABLE_MAIN_COURSE_USER);
	$tbl_session_rel_course_user = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
	$table_user_field_values = Database::get_main_table(TABLE_EXTRA_FIELD_VALUES);

    $courseCode = api_get_course_id();
    $sessionId = api_get_session_id();

	if (isset($_REQUEST['type']) && $_REQUEST['type'] === 'teacher') {
		if (api_get_session_id() != 0) {
			$sql = "SELECT COUNT(u.id)
					FROM $user_table u
					LEFT JOIN $tbl_session_rel_course_user cu
					ON
						u.user_id = cu.user_id AND
						c_id = '".api_get_course_int_id()."' AND
						session_id ='".$sessionId."'
					WHERE
						cu.user_id IS NULL AND
						u.status = 1 AND
						(u.official_code <> 'ADMIN' OR u.official_code IS NULL) ";

            if (api_is_multiple_url_enabled()) {
                $url_access_id = api_get_current_access_url_id();
                if ($url_access_id !=-1) {
                    $tbl_url_rel_user = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
                    $sql = "SELECT COUNT(u.id)
                            FROM $user_table u
                            LEFT JOIN $tbl_session_rel_course_user cu
                            ON
                                u.user_id = cu.user_id AND cu.c_id = '".api_get_course_int_id()."' AND
                                session_id ='".$sessionId."'
                            INNER JOIN  $tbl_url_rel_user as url_rel_user
                            ON (url_rel_user.user_id = u.user_id)
                            WHERE
                                cu.user_id IS NULL AND
                                access_url_id= $url_access_id AND
                                u.status = 1 AND
                                (u.official_code <> 'ADMIN' OR u.official_code IS NULL)
                            ";
                }
            }
        } else {
            $sql = "SELECT COUNT(u.id)
                    FROM $user_table u
                    LEFT JOIN $course_user_table cu
                    ON u.user_id = cu.user_id and c_id='".api_get_course_int_id()."'
                    WHERE cu.user_id IS NULL AND u.status<>".DRH." ";

            if (api_is_multiple_url_enabled()) {
                $url_access_id = api_get_current_access_url_id();
                if ($url_access_id !=-1) {
                    $tbl_url_rel_user = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);

                    $sql = "SELECT COUNT(u.id)
                        FROM $user_table u
                        LEFT JOIN $course_user_table cu
                        ON u.user_id = cu.user_id AND c_id='".api_get_course_int_id()."'
                        INNER JOIN  $tbl_url_rel_user as url_rel_user
                        ON (url_rel_user.user_id = u.user_id)
                        WHERE cu.user_id IS NULL AND u.status<>".DRH." AND access_url_id= $url_access_id ";
                }
            }
        }
    } else {
        // students
        if ($sessionId != 0) {
            $sql = "SELECT COUNT(u.id)
                    FROM $user_table u
                    LEFT JOIN $tbl_session_rel_course_user cu
                    ON
                        u.user_id = cu.user_id AND
                        c_id='".api_get_course_int_id()."' AND
                        session_id ='".$sessionId."'
                    WHERE
                        cu.user_id IS NULL AND
                        u.status<>".DRH." AND
                        (u.official_code <> 'ADMIN' OR u.official_code IS NULL) ";

            if (api_is_multiple_url_enabled()) {
                $url_access_id = api_get_current_access_url_id();
                if ($url_access_id !=-1) {
                    $tbl_url_rel_user = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
                    $sql = "SELECT COUNT(u.id)
                            FROM $user_table u
                            LEFT JOIN $tbl_session_rel_course_user cu
                            ON
                                u.user_id = cu.user_id AND
                                c_id='".api_get_course_int_id()."' AND
                                session_id ='".$sessionId."'
                            INNER JOIN $tbl_url_rel_user as url_rel_user
                            ON (url_rel_user.user_id = u.id)
                            WHERE
                                cu.user_id IS NULL AND
                                u.status<>".DRH." AND
                                access_url_id= $url_access_id AND
                                (u.official_code <> 'ADMIN' OR u.official_code IS NULL) ";
                }
            }
        } else {
            $sql = "SELECT COUNT(u.id)
                    FROM $user_table u
                    LEFT JOIN $course_user_table cu
                    ON u.user_id = cu.user_id AND c_id='".api_get_course_int_id()."'";

            // we change the SQL when we have a filter
            if (isset($_GET['subscribe_user_filter_value']) &&
                !empty($_GET['subscribe_user_filter_value']) &&
                api_get_setting('ProfilingFilterAddingUsers') === 'true'
            ){
                $field_identification = explode('*',$_GET['subscribe_user_filter_value']);
                $sql .=	"
                    LEFT JOIN $table_user_field_values field_values
                    ON field_values.item_id = u.user_id
                    WHERE
                        cu.user_id IS NULL AND
                        u.status <> ".DRH." AND
                        field_values.field_id = '".intval($field_identification[0])."' AND
                        field_values.value = '".Database::escape_string($field_identification[1])."'
                    ";
            } else	{
                $sql .=	"WHERE cu.user_id IS NULL AND u.status <> ".DRH." ";
            }

            if (api_is_multiple_url_enabled()) {
                $url_access_id = api_get_current_access_url_id();

                if ($url_access_id !=-1) {
                    $tbl_url_rel_user = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
                    $sql = "SELECT COUNT(u.id)
                            FROM $user_table u
                            LEFT JOIN $course_user_table cu 
                            ON u.user_id = cu.user_id AND c_id='".api_get_course_int_id()."'
                            INNER JOIN $tbl_url_rel_user as url_rel_user
                            ON (url_rel_user.user_id = u.id)
                            WHERE cu.user_id IS NULL AND access_url_id= $url_access_id AND u.status <> ".DRH." ";
                }
            }
        }
    }

    // when there is a keyword then we are searching and we have to change the SQL statement
    if (isset($_GET['keyword']) && !empty($_GET['keyword'])) {
        $keyword = Database::escape_string(trim($_REQUEST['keyword']));
        $sql .= " AND (
            firstname LIKE '%".$keyword."%' OR
            lastname LIKE '%".$keyword."%' OR
            email LIKE '%".$keyword."%' OR
            username LIKE '%".$keyword."%' OR
            official_code LIKE '%".$keyword."%'
        )";

        // we also want to search for users who have something in their profile fields that matches the keyword
        if (api_get_setting('ProfilingFilterAddingUsers') === 'true') {
            $additional_users = search_additional_profile_fields($keyword);
        }

        // getting all the users of the course (to make sure that we do not display users that are already in the course)
        if (!empty($sessionId)) {
            $a_course_users = CourseManager:: get_user_list_from_course_code(
                $courseCode,
                $sessionId
            );
        } else {
            $a_course_users = CourseManager:: get_user_list_from_course_code(
                $courseCode,
                0
            );
        }
        foreach ($a_course_users as $user_id => $course_user) {
            $users_of_course[] = $course_user['user_id'];
        }
    }
    $sql .=" AND u.status <> ".ANONYMOUS." ";
    $res = Database::query($sql);
    $count_user = 0;

    if ($res) {
       $row = Database::fetch_row($res);
       $count_user = $row[0];
    }

	return $count_user;
}
/**
 * Get the users to display on the current page.
 */
function get_user_data($from, $number_of_items, $column, $direction)
{
    $url_access_id = api_get_current_access_url_id();
    $course_code = api_get_course_id();
    $sessionId = api_get_session_id();
	$courseId = api_get_course_int_id();

	// Database table definitions
	$user_table = Database::get_main_table(TABLE_MAIN_USER);
	$course_user_table = Database::get_main_table(TABLE_MAIN_COURSE_USER);
	$tbl_session_rel_course_user = Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
	$table_user_field_values = Database::get_main_table(TABLE_EXTRA_FIELD_VALUES);
    $tbl_url_rel_user = Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);

    // adding teachers
	$is_western_name_order = api_is_western_name_order();

    if (api_get_setting('show_email_addresses') === 'true') {
        $select_fields = "u.id              AS col0,
                u.official_code        AS col1,
                ".($is_western_name_order
                ? "u.firstname         AS col2,
                u.lastname             AS col3,"
                : "u.lastname          AS col2,
                u.firstname            AS col3,")."
                u.email 	           AS col4,
                u.active               AS col5,
                u.user_id              AS col6";
    } else {
        $select_fields = "u.user_id    AS col0,
                u.official_code        AS col1,
                ".($is_western_name_order
                ? "u.firstname         AS col2,
                u.lastname             AS col3,"
                : "u.lastname          AS col2,
                u.firstname            AS col3,")."
                u.active               AS col4,
                u.user_id              AS col5";
    }
	if (isset($_REQUEST['type']) && $_REQUEST['type'] == COURSEMANAGER) {
		// adding a teacher through a session
		if (!empty($sessionId)) {
			$sql = "SELECT $select_fields
					FROM $user_table u
					LEFT JOIN $tbl_session_rel_course_user cu
					ON
						u.user_id = cu.user_id AND
						c_id ='".$courseId."' AND
						session_id ='".$sessionId."'
                    INNER JOIN  $tbl_url_rel_user as url_rel_user
                    ON (url_rel_user.user_id = u.user_id) ";

			// applying the filter of the additional user profile fields
			if (isset($_GET['subscribe_user_filter_value']) &&
				!empty($_GET['subscribe_user_filter_value']) &&
				api_get_setting('ProfilingFilterAddingUsers') == 'true'
			) {
				$field_identification = explode('*',$_GET['subscribe_user_filter_value']);
				$sql .=	"
					LEFT JOIN $table_user_field_values field_values
						ON field_values.item_id = u.user_id
					WHERE
						cu.user_id IS NULL AND
						u.status = 1 AND
						(u.official_code <> 'ADMIN' OR u.official_code IS NULL) AND
						field_values.field_id = '".intval($field_identification[0])."' AND
						field_values.value = '".Database::escape_string($field_identification[1])."'";
            } else {
                $sql .=	"WHERE cu.user_id IS NULL AND u.status=1 AND (u.official_code <> 'ADMIN' OR u.official_code IS NULL) ";
            }

            $sql .=	" AND access_url_id = $url_access_id";
		} else {
		     // adding a teacher NOT through a session
			$sql = "SELECT $select_fields
                    FROM $user_table u
                    LEFT JOIN $course_user_table cu
                    ON u.user_id = cu.user_id AND c_id = '".$courseId."'";

				// applying the filter of the additional user profile fields
				if (isset($_GET['subscribe_user_filter_value']) &&
					!empty($_GET['subscribe_user_filter_value']) &&
					api_get_setting('ProfilingFilterAddingUsers') == 'true'
				) {
					$field_identification = explode('*',$_GET['subscribe_user_filter_value']);
					$sql .=	"
						LEFT JOIN $table_user_field_values field_values
							ON field_values.item_id = u.user_id
						WHERE
							cu.user_id IS NULL AND u.status<>".DRH." AND
							field_values.field_id = '".intval($field_identification[0])."' AND
							field_values.value = '".Database::escape_string($field_identification[1])."'";
				} else	{
					$sql .=	"WHERE cu.user_id IS NULL AND u.status<>".DRH." ";
				}

				// adding a teacher NOT trough a session on a portal with multiple URLs
				if (api_is_multiple_url_enabled()) {
					if ($url_access_id !=-1) {
						$sql = "SELECT $select_fields
						FROM $user_table u
						LEFT JOIN $course_user_table cu
						ON u.user_id = cu.user_id and c_id='".$courseId."'
						INNER JOIN  $tbl_url_rel_user as url_rel_user
						ON (url_rel_user.user_id = u.user_id) ";

					// applying the filter of the additional user profile fields
					if (isset($_GET['subscribe_user_filter_value']) &&
						!empty($_GET['subscribe_user_filter_value']) &&
						api_get_setting('ProfilingFilterAddingUsers') == 'true'
					){
						$field_identification = explode('*', $_GET['subscribe_user_filter_value']);
						$sql .=	"
							LEFT JOIN $table_user_field_values field_values
								ON field_values.item_id = u.user_id
							WHERE
							 	cu.user_id IS NULL AND
							 	u.status<>".DRH." AND
							 	field_values.field_id = '".intval($field_identification[0])."' AND
							 	field_values.value = '".Database::escape_string($field_identification[1])."'";
					} else	{
						$sql .=	"WHERE cu.user_id IS NULL AND u.status<>".DRH." AND access_url_id= $url_access_id ";
					}
				}
			}
		}
	} else {
		// adding a student
		if (!empty($sessionId)) {
			$sql = "SELECT $select_fields
                    FROM $user_table u
                    LEFT JOIN $tbl_session_rel_course_user cu
                    ON
                    	u.user_id = cu.user_id AND
                    	c_id ='".$courseId."' AND
                    	session_id ='".$sessionId."' ";

            if (api_is_multiple_url_enabled()) {
                $sql .= " INNER JOIN $tbl_url_rel_user as url_rel_user ON (url_rel_user.user_id = u.user_id) ";
            }

            // applying the filter of the additional user profile fields
            if (isset($_GET['subscribe_user_filter_value']) AND !empty($_GET['subscribe_user_filter_value'])){
                $field_identification = explode('*',$_GET['subscribe_user_filter_value']);
                $sql .=	"
                    LEFT JOIN $table_user_field_values field_values
                        ON field_values.item_id = u.user_id
                    WHERE
                    	cu.user_id IS NULL AND
                    	u.status<>".DRH." AND
                    	(u.official_code <> 'ADMIN' OR u.official_code IS NULL) AND
                    	field_values.field_id = '".intval($field_identification[0])."' AND
                    	field_values.value = '".Database::escape_string($field_identification[1])."'";
            } else	{
                $sql .=	"WHERE
                			cu.user_id IS NULL AND
                			u.status<>".DRH." AND
                			(u.official_code <> 'ADMIN' OR u.official_code IS NULL) ";
            }

            if (api_is_multiple_url_enabled()) {
                $sql .=  "AND access_url_id = $url_access_id";
            }

		} else {
            $sql = "SELECT $select_fields
                    FROM $user_table u
                    LEFT JOIN $course_user_table cu
                    ON
                    	u.user_id = cu.user_id AND
                    	c_id ='".$courseId."'";

			// applying the filter of the additional user profile fields
			if (isset($_GET['subscribe_user_filter_value']) && !empty($_GET['subscribe_user_filter_value'])) {
				$field_identification = explode('*',$_GET['subscribe_user_filter_value']);
				$sql .=	"
					LEFT JOIN $table_user_field_values field_values
						ON field_values.item_id = u.user_id
					WHERE
						cu.user_id IS NULL AND
						u.status<>".DRH." AND
						field_values.field_id = '".intval($field_identification[0])."' AND
						field_values.value = '".Database::escape_string($field_identification[1])."'";
			} else	{
				$sql .=	"WHERE cu.user_id IS NULL AND u.status<>".DRH." ";
			}

			//showing only the courses of the current Chamilo access_url_id

			if (api_is_multiple_url_enabled()) {
				if ($url_access_id !=-1) {
					$sql = "SELECT $select_fields
						FROM $user_table u
						LEFT JOIN $course_user_table cu
						ON u.user_id = cu.user_id AND c_id='".$courseId."'
						INNER JOIN  $tbl_url_rel_user as url_rel_user
						ON (url_rel_user.user_id = u.user_id) ";

					// applying the filter of the additional user profile fields
					if (isset($_GET['subscribe_user_filter_value']) &&
						!empty($_GET['subscribe_user_filter_value']) &&
						api_get_setting('ProfilingFilterAddingUsers') == 'true'
					){
						$field_identification = explode('*', $_GET['subscribe_user_filter_value']);
						$sql .=	"
							LEFT JOIN $table_user_field_values field_values
								ON field_values.item_id = u.user_id
							WHERE
								cu.user_id IS NULL AND
								u.status<>".DRH." AND
								field_values.field_id = '".intval($field_identification[0])."' AND
								field_values.value = '".Database::escape_string($field_identification[1])."' AND
								access_url_id = $url_access_id
                            ";
					} else	{
						$sql .=	"WHERE cu.user_id IS NULL AND u.status<>".DRH." AND access_url_id= $url_access_id ";
					}
				}
			}
		}
	}

	// adding additional WHERE statements to the SQL for the search functionality
	if (isset($_REQUEST['keyword'])) {
		$keyword = Database::escape_string(trim($_REQUEST['keyword']));
		$sql .= " AND (
					firstname LIKE '%".$keyword."%' OR
					lastname LIKE '%".$keyword."%' OR
					email LIKE '%".$keyword."%' OR
					username LIKE '%".$keyword."%' OR
					official_code LIKE '%".$keyword."%'
					)
				";

		if (api_get_setting('ProfilingFilterAddingUsers') === 'true') {
			// we also want to search for users who have something in
			// their profile fields that matches the keyword
			$additional_users = search_additional_profile_fields($keyword);
		}

		// getting all the users of the course (to make sure that we do not
		// display users that are already in the course)
		if (!empty($sessionId)) {
			$a_course_users = CourseManager :: get_user_list_from_course_code($course_code, $sessionId);
		} else {
			$a_course_users = CourseManager :: get_user_list_from_course_code($course_code, 0);
	    }
		foreach ($a_course_users as $user_id=>$course_user) {
			$users_of_course[] = $course_user['user_id'];
		}
	}

	$sql .=" AND u.status != ".ANONYMOUS." ";

	// Sorting and pagination (used by the sortable table)
	$sql .= " ORDER BY col$column $direction ";
    $from = (int) $from;
    $number_of_items = (int) $number_of_items;
	$sql .= " LIMIT $from, $number_of_items";

	$res = Database::query($sql);
	$users = array ();
	while ($user = Database::fetch_row($res)) {
		$users[] = $user;
	}

	return $users;
}
/**
* Returns a mailto-link
* @param string $email An email-address
* @return string HTML-code with a mailto-link
*/
function email_filter($email)
{
	return Display :: encrypted_mailto_link($email, $email);
}
/**
 * Build the reg-column of the table
 * @param int $user_id The user id
 * @return string Some HTML-code
 */
function reg_filter($user_id)
{
    if (isset($_REQUEST['type']) && $_REQUEST['type'] == COURSEMANAGER) {
        $type = COURSEMANAGER;
    } else {
        $type = STUDENT;
    }
    $user_id = (int) $user_id;

	$result = '<a class="btn btn-small btn-primary" href="'.api_get_self().'?'.api_get_cidreq().'&register=yes&type='.$type.'&user_id='.$user_id.'">'.
        get_lang("reg").'</a>';

	return $result;
}

/**
 * Build the active-column of the table to lock or unlock a certain user
 * lock = the user can no longer use this account
 * @author Patrick Cool <patrick.cool@UGent.be>, Ghent University
 * @param int $active the current state of the account
 * @param int $user_id The user id
 * @param string $url_params
 * @return string Some HTML-code with the lock/unlock button
 */
function active_filter($active, $url_params, $row)
{
	$_user = api_get_user_info();
    if ($active == '1') {
        $action = 'AccountActive';
        $image = 'accept';
    }

    if ($active == '0') {
        $action = 'AccountInactive';
        $image = 'error';
	}
    $result = '';
    if ($row['0'] <> $_user['user_id']) {
	// you cannot lock yourself out otherwise you could disable all the accounts
	// including your own => everybody is locked out and nobody can change it anymore.
		$result = Display::return_icon($image.'.png',  get_lang(ucfirst($action)), array() , ICON_SIZE_TINY);
	}

	return $result;
}

/**
 * Search the additional user profile fields defined by the platform administrator in
 * platform administration > profiling for a given keyword.
 * We not only search in the predefined options but also in the input fields wherer
 * the user can enter some text.
 *
 * For this we get the additional profile field options that match the (search) keyword,
 * then we find all the users who have entered the (search)keyword in a input field of the
 * additional profile fields or have chosen one of the matching predefined options
 *
 * @param string $keyword a keyword we are looking for in the additional profile fields
 * @return array $additional_users an array with the users who have an additional profile field that matches the keyword
 */
function search_additional_profile_fields($keyword)
{
	// database table definitions
	$table_user_field_options = Database :: get_main_table(TABLE_EXTRA_FIELD_OPTIONS);
	$table_user_field_values = Database::get_main_table(TABLE_EXTRA_FIELD_VALUES);
    $tableExtraField = Database::get_main_table(TABLE_EXTRA_FIELD);
	$table_user = Database::get_main_table(TABLE_MAIN_USER);

    $keyword = Database::escape_string($keyword);
	// getting the field option text that match this keyword (for radio buttons and checkboxes)
	$sql = "SELECT * FROM $table_user_field_options
	        WHERE display_text LIKE '%".$keyword."%'";
	$result_profiling = Database::query($sql);
	while ($profiling_field_options = Database::fetch_array($result_profiling)) {
		$profiling_field_options_exact_values[] = $profiling_field_options;
	}
    $profiling_field_options_exact_values_sql = '';
	foreach ($profiling_field_options_exact_values as $profilingkey => $profilingvalue) {
		$profiling_field_options_exact_values_sql .= " OR (field_id = '".$profilingvalue['field_id']."' AND value='".$profilingvalue['option_value']."') ";
	}

    $extraFieldType = ExtraField::USER_FIELD_TYPE;

	// getting all the user ids of the users who have chosen on of the predefined fields that contain the keyword
	// or all the users who have entered the keyword in a free-form field
	$sql = "SELECT
	            user.user_id as col0,
	            user.official_code as col1,
	            user.lastname as col2,
	            user.firstname as col3,
	            user.email as col4,
	            user.active as col5,
	            user.user_id as col6
            FROM $table_user user, $table_user_field_values user_values, $tableExtraField e
            WHERE
                user.user_id = user_values.item_id AND
                user_values.field_id = e.id AND
                e.extra_field_type = $extraFieldType AND
                (value LIKE '%".$keyword."%'".$profiling_field_options_exact_values_sql.")";
	$result = Database::query($sql);
    $additional_users = array();
	while ($profiled_users = Database::fetch_array($result)) {
		$additional_users[$profiled_users['col0']] = $profiled_users;
	}

	return $additional_users;
}

/**
 * This function displays a dropdown list with all the additional user
 * profile fields defined by the platform administrator in
 * platform administration > profiling.
 * Only the fields that have predefined fields are usefull for such a filter.
 *
 */
function display_extra_profile_fields_filter()
{
	// getting all the additional user profile fields
    $extra = UserManager::get_extra_fields(0, 50, 5, 'ASC');
	$return = '<option value="">'.get_lang('SelectFilter').'</option>';

	// looping through the additional user profile fields
	foreach ($extra as $id => $field_details) {
		// $field_details[2] contains the type of the additional user profile field
		switch ($field_details[2]) {
			// text fields cannot be used as a filter
			case ExtraFieldModel::FIELD_TYPE_TEXT:
				break;
			// text area fields cannot be used as a filter
			case ExtraFieldModel::FIELD_TYPE_TEXTAREA:
				break;
			case ExtraFieldModel::FIELD_TYPE_RADIO:
			case ExtraFieldModel::FIELD_TYPE_SELECT:
			case ExtraFieldModel::FIELD_TYPE_SELECT_MULTIPLE:
				$return .= '<optgroup label="'.$field_details[3].'">';
				foreach ($field_details[9] as $option_id => $option_details) {
					if (isset($_GET['subscribe_user_filter_value']) &&
                        $_GET['subscribe_user_filter_value'] == $field_details[0].'*'.$option_details[1]
                    ) {
						$selected = 'selected="selected"';
					} else {
						$selected = false;
					}
					$return .= '<option value="'.$field_details[0].'*'.$option_details[1].'" '.$selected.'>'.$option_details[2].'</option>';
				}
				$return .= '</optgroup>';
				break;
		}
	}

	$html = '<form class="form-inline" id="subscribe_user_filter" name="subscribe_user_filter" method="get" action="'.api_get_self().'?'.api_get_cidreq().'">';
	$html .= '<input type="hidden" name="type" id="type" value="'.Security::remove_XSS($_REQUEST['type']).'" />';
	$html .= '<select name="subscribe_user_filter_value" id="subscribe_user_filter_value">'.$return.'</select>';
	$html .= '<button type="submit" name="submit_filter" id="submit_filter" value="" class="search">'.get_lang('Filter').'</button>';
	$html .= '</form>';

    return $html;
}