Browse Source

[svn r18798] Create library sessionmanager with functions add, edit, delete sessions and add_users_to_session see FS#3749

Carlos Vargas 16 years ago
parent
commit
16536d521d

+ 2 - 1
main/admin/add_users_to_session.php

@@ -82,6 +82,7 @@ if(!api_is_platform_admin()) {
 
 //checking for extra field with filter on
 include_once (api_get_path(LIBRARY_PATH).'usermanager.lib.php');
+include_once (api_get_path(LIBRARY_PATH).'sessionmanager.lib.php');
 $extra_field_list= UserManager::get_extra_fields();
 $new_field_list = array();
 if (is_array($extra_field_list)) {
@@ -211,7 +212,7 @@ if($_POST['form_sent']) {
 
 	if ($form_sent == 1) {
 		
-		UserManager::suscribe_users_to_session($id_session,$UserList,true);
+		SessionManager::suscribe_users_to_session($id_session,$UserList,true);
 		
 		//adding the session to the access_url_rel_session table
 		global $_configuration;

+ 26 - 72
main/admin/session_add.php

@@ -24,9 +24,9 @@ $language_file='admin';
 
 $cidReset=true;
 
-include('../inc/global.inc.php');
-
-require_once ('../inc/lib/xajax/xajax.inc.php');
+require_once('../inc/global.inc.php');
+require_once(api_get_path(LIBRARY_PATH).'sessionmanager.lib.php');
+require_once('../inc/lib/xajax/xajax.inc.php');
 $xajax = new xajax();
 //$xajax->debugOn();
 $xajax -> registerFunction ('search_coachs');
@@ -39,6 +39,10 @@ api_protect_admin_script(true);
 $formSent=0;
 $errorMsg='';
 
+$tool_name = get_lang('AddSession');
+$interbreadcrumb[]=array('url' => 'index.php',"name" => get_lang('PlatformAdmin'));
+$interbreadcrumb[]=array('url' => "session_list.php","name" => get_lang('SessionList'));
+
 // Database Table Definitions
 $tbl_user		= Database::get_main_table(TABLE_MAIN_USER);
 $tbl_session	= Database::get_main_table(TABLE_MAIN_SESSION);
@@ -105,90 +109,40 @@ function fill_coach_field (username) {
 }
 </script>';
 
-$tool_name = get_lang('AddSession');
-
-$interbreadcrumb[]=array('url' => 'index.php',"name" => get_lang('PlatformAdmin'));
-$interbreadcrumb[]=array('url' => "session_list.php","name" => get_lang('SessionList'));
-
-$nb_days_acess_before = 0;
-$nb_days_acess_after = 0;
 
 if ($_POST['formSent']) {
 	$formSent=1;
-
-	$name=trim(stripslashes($_POST['name']));
-	$year_start=intval($_POST['year_start']);
-	$month_start=intval($_POST['month_start']);
-	$day_start=intval($_POST['day_start']);
-	$year_end=intval($_POST['year_end']);
-	$month_end=intval($_POST['month_end']);
-	$day_end=intval($_POST['day_end']);
-	$nb_days_acess_before = intval($_POST['nb_days_acess_before']);
-	$nb_days_acess_after = intval($_POST['nb_days_acess_after']);
-	
-	$sql = 'SELECT user_id FROM '.$tbl_user.' WHERE username="'.Database::escape_string($_POST['coach_username']).'"';
-	$rs = api_sql_query($sql, __FILE__, __LINE__);
-	$id_coach = Database::result($rs,0,'user_id');
-
-	if (empty($_POST['nolimit'])){
-		$date_start="$year_start-".(($month_start < 10)?"0$month_start":$month_start)."-".(($day_start < 10)?"0$day_start":$day_start);
-		$date_end="$year_end-".(($month_end < 10)?"0$month_end":$month_end)."-".(($day_end < 10)?"0$day_end":$day_end);
-	} else {
-		$date_start="000-00-00";
-		$date_end="000-00-00";
-	}
+	$name= trim($_POST['name']);
+	$year_start= intval($_POST['year_start']); 
+	$month_start=intval($_POST['month_start']); 
+	$day_start=intval($_POST['day_start']); 
+	$year_end=intval($_POST['year_end']); 
+	$month_end=intval($_POST['month_end']); 
+	$day_end=intval($_POST['day_end']); 
+	$nb_days_acess_before = intval($_POST['nb_days_acess_before']); 
+	$nb_days_acess_after = intval($_POST['nb_days_acess_after']); 
+	$nolimit=$_POST['nolimit'];
+	$coach_username=$_POST['coach_username'];
 	
-	if(empty($name)) $errorMsg=get_lang('SessionNameIsRequired');
-	elseif(empty($_POST['nolimit']) && (!$month_start || !$day_start || !$year_start || !checkdate($month_start,$day_start,$year_start))) $errorMsg=get_lang('InvalidStartDate');
-	elseif(empty($_POST['nolimit']) && (!$month_end || !$day_end || !$year_end || !checkdate($month_end,$day_end,$year_end))) $errorMsg=get_lang('InvalidEndDate');
-	elseif(empty($_POST['nolimit']) && $date_start >= $date_end) $errorMsg=get_lang('StartDateShouldBeBeforeEndDate');
-	else
-	{
-		$rs = api_sql_query("SELECT 1 FROM $tbl_session WHERE name='".addslashes($name)."'");
-		if(Database::num_rows($rs)){
-			$errorMsg = get_lang('SessionNameSoonExists');
-		} else {
-			api_sql_query("INSERT INTO $tbl_session(name,date_start,date_end,id_coach,session_admin_id, nb_days_access_before_beginning, nb_days_access_after_end) VALUES('".addslashes($name)."','$date_start','$date_end','$id_coach',".intval($_user['user_id']).",".$nb_days_acess_before.", ".$nb_days_acess_after.")",__FILE__,__LINE__);
-			$id_session=Database::get_last_insert_id();
-			header('Location: add_courses_to_session.php?id_session='.$id_session.'&add=true');
-			exit();
-		}
-	}
+	$id_session=SessionManager::AddSession($name,$year_start,$month_start,$day_start,$year_end,$month_end,$day_end,$nb_days_acess_before,$nb_days_acess_after,$nolimit,$coach_username);
+	header('Location: add_courses_to_session.php?id_session='.$id_session.'&add=true');
+	exit();
 }
 
+Display::display_header($tool_name);
+api_display_tool_title($tool_name);
+
+$nb_days_acess_before = 0;
+$nb_days_acess_after = 0;
 
 $thisYear=date('Y');
 $thisMonth=date('m');
 $thisDay=date('d');
-
-Display::display_header($tool_name);
-api_display_tool_title($tool_name);
 ?>
-
 <form method="post" name="form" action="<?php echo api_get_self(); ?>" style="margin:0px;">
 <input type="hidden" name="formSent" value="1">
 
 <table border="0" cellpadding="5" cellspacing="0" width="550">
-
-<?php
-if(!empty($errorMsg))
-{
-?>
-
-<tr>
-  <td colspan="2">
-
-<?php
-	Display::display_normal_message($errorMsg);
-?>
-
-  </td>
-</tr>
-
-<?php
-}
-?>
-
 <tr>
   <td width="30%"><?php echo get_lang('SessionName') ?>&nbsp;&nbsp;</td>
   <td width="70%"><input type="text" name="name" size="50" maxlength="50" value="<?php if($formSent) echo htmlentities($name,ENT_QUOTES,$charset); ?>"></td>

+ 6 - 57
main/admin/session_edit.php

@@ -23,6 +23,7 @@
 $language_file ='admin';
 $cidReset=true;
 include('../inc/global.inc.php');
+require_once (api_get_path(LIBRARY_PATH).'sessionmanager.lib.php');
 
 // setting the section (for the tabs)
 $this_section=SECTION_PLATFORM_ADMIN;
@@ -67,46 +68,12 @@ if ($_POST['formSent']) {
 	$month_end=intval($_POST['month_end']);
 	$day_end=intval($_POST['day_end']);
 	$id_coach=intval($_POST['id_coach']);
-	$nb_days_access_before = intval($_POST['nb_days_access_before']);
-	$nb_days_access_after = intval($_POST['nb_days_access_after']);
+	$nb_days_acess_before = intval($_POST['nb_days_access_before']);
+	$nb_days_acess_after = intval($_POST['nb_days_access_after']);
 	
-	if (empty($_POST['nolimit'])) {
-		$date_start="$year_start-".(($month_start < 10)?"0$month_start":$month_start)."-".(($day_start < 10)?"0$day_start":$day_start);
-		$date_end="$year_end-".(($month_end < 10)?"0$month_end":$month_end)."-".(($day_end < 10)?"0$day_end":$day_end);
-	} else {
-		$date_start="000-00-00";
-		$date_end="000-00-00";
-	}
-	if(empty($name)) $errorMsg=get_lang('SessionNameIsRequired');
-	elseif(empty($_POST['nolimit']) && (!$month_start || !$day_start || !$year_start || !checkdate($month_start,$day_start,$year_start))) $errorMsg=get_lang('InvalidStartDate');
-	elseif(empty($_POST['nolimit']) && (!$month_end || !$day_end || !$year_end || !checkdate($month_end,$day_end,$year_end))) $errorMsg=get_lang('InvalidEndDate');
-	elseif(empty($_POST['nolimit']) && $date_start >= $date_end) $errorMsg=get_lang('StartDateShouldBeBeforeEndDate');
-	else {		
-		$rs = api_sql_query("SELECT id FROM $tbl_session WHERE name='".addslashes($name)."'");
-		$exists = false;
-		while($row = mysql_fetch_array($rs)) {
-			if($row['id']!=$id)
-				$exists = true;
-		}
-		if ($exists) {
-			$errorMsg = get_lang('SessionNameSoonExists');
-		} else {
-			api_sql_query("UPDATE $tbl_session
-					   SET name='".addslashes($name)."',
-						   date_start='$date_start',
-						   date_end='$date_end',
-						   id_coach='$id_coach',
-						   nb_days_access_before_beginning = ".$nb_days_access_before.",
-						   nb_days_access_after_end = ".$nb_days_access_after." 
-					   WHERE id='$id'",__FILE__,__LINE__);
-			$sqlu = "UPDATE $tbl_session_rel_course
-					   SET id_coach='$id_coach'						   
-					   WHERE id_session='$id'";
-			api_sql_query($sqlu,__FILE__,__LINE__);
-			header('Location: resume_session.php?id_session='.$id);
-			exit();
-		}
-	}
+	SessionManager::EditSession($name,$year_start,$month_start,$day_start,$year_end,$month_end,$day_end,$nb_days_acess_before,$nb_days_acess_after,$nolimit,$id_coach,$id);
+	header('Location: resume_session.php?id_session='.$id);
+	exit();
 }
 
 $sql="SELECT user_id,lastname,firstname,username FROM $tbl_user WHERE status='1' ORDER BY lastname,firstname,username";
@@ -136,24 +103,6 @@ api_display_tool_title($tool_name);
 
 <table border="0" cellpadding="5" cellspacing="0" width="550">
 
-<?php
-if(!empty($errorMsg)) {
-?>
-
-<tr>
-  <td colspan="2">
-
-<?php
-	Display::display_normal_message($errorMsg);
-?>
-
-  </td>
-</tr>
-
-<?php
-}
-?>
-
 <tr>
   <td width="30%"><?php echo get_lang('SessionName') ?>&nbsp;&nbsp;</td>
   <td width="70%"><input type="text" name="name" size="50" maxlength="50" value="<?php if($formSent) echo htmlentities($name,ENT_QUOTES,$charset); else echo htmlentities($infos['name'],ENT_QUOTES,$charset); ?>"></td>

+ 3 - 21
main/admin/session_list.php

@@ -24,6 +24,7 @@ $cidReset=true;
 
 include('../inc/global.inc.php');
 require_once (api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php');
+require_once (api_get_path(LIBRARY_PATH).'sessionmanager.lib.php');
 
 api_protect_admin_script(true);
 
@@ -39,33 +40,14 @@ $sort=in_array($_GET['sort'],array('name','nbr_courses','date_start','date_end')
 $idChecked = $_REQUEST['idChecked'];
 
 if ($action == 'delete') {
-	if(is_array($idChecked)) {
-		$idChecked=Database::escape_string(implode(',',$idChecked));
-	} else {
-		$idChecked=intval($idChecked);
-	}
-	
-	if (!api_is_platform_admin()) {
-		$sql = 'SELECT session_admin_id FROM '.Database :: get_main_table(TABLE_MAIN_SESSION).' WHERE id='.$idChecked;
-		$rs = api_sql_query($sql,__FILE__,__LINE__);
-		if (Database::result($rs,0,0)!=$_user['user_id']) {
-			api_not_allowed(true);
-		}
-	}
-
-	api_sql_query("DELETE FROM $tbl_session WHERE id IN($idChecked)",__FILE__,__LINE__);
-	api_sql_query("DELETE FROM $tbl_session_rel_course WHERE id_session IN($idChecked)",__FILE__,__LINE__);
-	api_sql_query("DELETE FROM $tbl_session_rel_course_rel_user WHERE id_session IN($idChecked)",__FILE__,__LINE__);	
-	api_sql_query("DELETE FROM $tbl_session_rel_user WHERE id_session IN($idChecked)",__FILE__,__LINE__);
-
+	SessionManager::DeleteSession($idChecked);
 	header('Location: '.api_get_self().'?sort='.$sort);
 	exit();
 }
 
 $interbreadcrumb[]=array("url" => "index.php","name" => get_lang('PlatformAdmin'));
 
-if (isset ($_GET['search']) && $_GET['search'] == 'advanced')
-{
+if (isset ($_GET['search']) && $_GET['search'] == 'advanced') {
 	
 	$interbreadcrumb[] = array ("url" => 'session_list.php', "name" => get_lang('SessionList'));
 	$tool_name = get_lang('SearchASession');

+ 321 - 0
main/inc/lib/sessionmanager.lib.php

@@ -0,0 +1,321 @@
+<?php
+/*
+==============================================================================
+	Dokeos - elearning and course management software
+
+	Copyright (c) 2004-2009 Dokeos SPRL
+	Copyright (c) 2003 Ghent University (UGent)
+	Copyright (c) 2001 Universite catholique de Louvain (UCL)
+	Copyright (c) various contributors
+	Copyright (c) Bart Mollet, Hogeschool Gent
+
+	For a full list of contributors, see "credits.txt".
+	The full license can be read in "license.txt".
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	See the GNU General Public License for more details.
+
+	Contact: Dokeos, rue du Corbeau, 108, B-1030 Brussels, Belgium, info@dokeos.com
+==============================================================================
+*/
+/**
+==============================================================================
+*	This library provides functions for user management.
+*	Include/require it in your code to use its functionality.
+*
+*	@package dokeos.library
+==============================================================================
+*/
+require_once('display.lib.php');
+class SessionManager{
+	
+	 /** Create a session 
+	  * @author Carlos Vargas <carlos.vargas@dokeos.com>,
+	  * @param	array	name, year_start,month_start, day_start,year_end,month_end,day_end,nb_days_acess_before,nb_days_acess_after
+	  **/
+	function AddSession($name,$year_start,$month_start,$day_start,$year_end,$month_end,$day_end,$nb_days_acess_before,$nb_days_acess_after,$nolimit,$coach_username) {
+		$tbl_user		= Database::get_main_table(TABLE_MAIN_USER);
+		$tbl_session	= Database::get_main_table(TABLE_MAIN_SESSION);
+		global $_user;	
+		
+		$sql = 'SELECT user_id FROM '.$tbl_user.' WHERE username="'.Database::escape_string($coach_username).'"';
+		$rs = api_sql_query($sql, __FILE__, __LINE__);
+		$id_coach = Database::result($rs,0,'user_id');
+	
+		if (empty($nolimit)){
+			$date_start="$year_start-".(($month_start < 10)?"0$month_start":$month_start)."-".(($day_start < 10)?"0$day_start":$day_start);
+			$date_end="$year_end-".(($month_end < 10)?"0$month_end":$month_end)."-".(($day_end < 10)?"0$day_end":$day_end);
+		} else {
+			$date_start="000-00-00";
+			$date_end="000-00-00";
+		}
+		if(empty($name)) {
+			Display::display_normal_message(get_lang('SessionNameIsRequired'));
+		} elseif (empty($coach_username))   {
+			Display::display_normal_message(get_lang('CoachIsRequired'));
+		} elseif (empty($nolimit) && (!$month_start || !$day_start || !$year_start || !checkdate($month_start,$day_start,$year_start))) {
+			Display::display_normal_message(get_lang('InvalidStartDate'));
+		} elseif (empty($nolimit) && (!$month_end || !$day_end || !$year_end || !checkdate($month_end,$day_end,$year_end))) {
+			Display::display_normal_message(get_lang('InvalidEndDate'));
+		} elseif(empty($nolimit) && $date_start >= $date_end) {
+			Display::display_normal_message(get_lang('StartDateShouldBeBeforeEndDate'));
+		} else {
+			$rs = api_sql_query("SELECT 1 FROM $tbl_session WHERE name='".addslashes($name)."'");
+			if(Database::num_rows($rs)) {
+				Display::display_normal_message(get_lang('SessionNameSoonExists'));
+			} else {
+				api_sql_query("INSERT INTO $tbl_session(name,date_start,date_end,id_coach,session_admin_id, nb_days_access_before_beginning, nb_days_access_after_end) VALUES('".addslashes($name)."','$date_start','$date_end','$id_coach',".intval($_user['user_id']).",".$nb_days_acess_before.", ".$nb_days_acess_after.")",__FILE__,__LINE__);
+				$id_session=Database::get_last_insert_id();	
+				return $id_session; 
+			}
+		}
+	}	
+	/** Edit a session 
+	 * @author Carlos Vargas <carlos.vargas@dokeos.com>,
+	 * @param	array	name, year_start,month_start, day_start,year_end,month_end,day_end,nb_days_acess_before,nb_days_acess_after,id
+	 * The parameter id is a primary key
+	**/
+	function EditSession($name,$year_start,$month_start,$day_start,$year_end,$month_end,$day_end,$nb_days_acess_before,$nb_days_acess_after,$nolimit,$id_coach,$id) {
+			
+		$tbl_user		= Database::get_main_table(TABLE_MAIN_USER);
+		$tbl_session	= Database::get_main_table(TABLE_MAIN_SESSION);
+		$tbl_session_rel_course = Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
+		global $_user;
+			
+		if (empty($nolimit)) {
+			$date_start="$year_start-".(($month_start < 10)?"0$month_start":$month_start)."-".(($day_start < 10)?"0$day_start":$day_start);
+			$date_end="$year_end-".(($month_end < 10)?"0$month_end":$month_end)."-".(($day_end < 10)?"0$day_end":$day_end);
+		} else {
+			$date_start="000-00-00";
+			$date_end="000-00-00";
+		}
+		if(empty($name)){
+			Display::display_normal_message(get_lang('SessionNameIsRequired'));
+		} elseif(!empty($nolimit) && (!$month_start || !$day_start || !$year_start || !checkdate($month_start,$day_start,$year_start))) {
+			Display::display_normal_message(get_lang('InvalidStartDate'));
+		} elseif(!empty($nolimit) && (!$month_end || !$day_end || !$year_end || !checkdate($month_end,$day_end,$year_end))) {
+			Display::display_normal_message(get_lang('InvalidEndDate'));
+		} elseif(!empty($nolimit) && $date_start >= $date_end) {
+			Display::display_normal_message(get_lang('StartDateShouldBeBeforeEndDate'));
+		} else {		
+			$rs = api_sql_query("SELECT id FROM $tbl_session WHERE name='".addslashes($name)."'");
+			$exists = false;
+			while($row = mysql_fetch_array($rs)) {
+				if($row['id']!=$id)
+					$exists = true;
+			}
+			if ($exists) {
+				Display::display_normal_message(get_lang('SessionNameSoonExists'));
+			} else {
+				$sql="UPDATE $tbl_session " .
+					"SET name='".addslashes($name)."',
+						date_start='".$date_start."',
+						date_end='".$date_end."',
+						id_coach='".$id_coach."',
+						nb_days_access_before_beginning = ".$nb_days_acess_before.",
+						nb_days_access_after_end = ".$nb_days_acess_after." 
+					  WHERE id='$id'";
+				api_sql_query($sql,__FILE__,__LINE__);
+				$sqlu = "UPDATE $tbl_session_rel_course " .
+						  " SET id_coach='$id_coach'" .
+						  " WHERE id_session='$id'";
+				api_sql_query($sqlu,__FILE__,__LINE__);
+				return $id;
+			}
+		}
+	}
+	  /** Delete session 
+	  * @author Carlos Vargas <carlos.vargas@dokeos.com>,
+	  * @param	array	idChecked
+	  * The parameters is a array to delete sessions 
+	  **/
+	
+	function DeleteSession($idChecked) {
+		$tbl_session=Database::get_main_table(TABLE_MAIN_SESSION);
+		$tbl_session_rel_course=Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
+		$tbl_session_rel_course_rel_user=Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
+		$tbl_session_rel_user=Database::get_main_table(TABLE_MAIN_SESSION_USER);
+		$tbl_user = Database::get_main_table(TABLE_MAIN_USER);
+		global $_user;
+		if(is_array($idChecked)) {
+			$idChecked=Database::escape_string(implode(',',$idChecked));
+		} else {
+			$idChecked=intval($idChecked);
+		}
+		
+		if (!api_is_platform_admin()) {
+			$sql = 'SELECT session_admin_id FROM '.Database :: get_main_table(TABLE_MAIN_SESSION).' WHERE id='.$idChecked;
+			$rs = api_sql_query($sql,__FILE__,__LINE__);
+			if (Database::result($rs,0,0)!=$_user['user_id']) {
+				api_not_allowed(true);
+			}
+		}
+	
+		api_sql_query("DELETE FROM $tbl_session WHERE id IN($idChecked)",__FILE__,__LINE__);
+		api_sql_query("DELETE FROM $tbl_session_rel_course WHERE id_session IN($idChecked)",__FILE__,__LINE__);
+		api_sql_query("DELETE FROM $tbl_session_rel_course_rel_user WHERE id_session IN($idChecked)",__FILE__,__LINE__);	
+		api_sql_query("DELETE FROM $tbl_session_rel_user WHERE id_session IN($idChecked)",__FILE__,__LINE__);
+	}	
+	
+	 /**Subscribes users to the given session and optionally (default) unsubscribes previous users
+	 * @author Carlos Vargas <carlos.vargas@dokeos.com>,
+     * @param	int		Session ID
+     * @param	array	List of user IDs
+     * @param	bool	Whether to unsubscribe existing users (true, default) or not (false)
+     * @return	void	Nothing, or false on error  
+     */
+	function suscribe_users_to_session($id_session,$UserList,$empty_users=true){
+	 	
+	  	if ($id_session!= strval(intval($id_session))) return false;
+	   	foreach($UserList as $intUser){
+	   		if ($intUser!= strval(intval($intUser))) return false;
+	   	}
+	   	$tbl_session_rel_course				= Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
+		$tbl_session_rel_course_rel_user	= Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
+	   	$tbl_session_rel_user = Database::get_main_table(TABLE_MAIN_SESSION_USER);
+	   	$tbl_session						= Database::get_main_table(TABLE_MAIN_SESSION);
+	   	
+	   	$sql = "SELECT id_user FROM $tbl_session_rel_user WHERE id_session='$id_session'";
+		$result = api_sql_query($sql,__FILE__,__LINE__);
+		$existingUsers = array();
+		while($row = Database::fetch_array($result)){
+			$existingUsers[] = $row['id_user'];
+		}
+		$sql = "SELECT course_code FROM $tbl_session_rel_course WHERE id_session='$id_session'";
+		$result=api_sql_query($sql,__FILE__,__LINE__);
+		$CourseList=array();
+	
+		while($row=Database::fetch_array($result)) {
+			$CourseList[]=$row['course_code'];
+		}
+	
+		foreach ($CourseList as $enreg_course) {
+			// for each course in the session
+			$nbr_users=0;
+	        $enreg_course = Database::escape_string($enreg_course);
+				// delete existing users
+			if ($empty_users!==false) {
+				foreach ($existingUsers as $existing_user) {
+					if(!in_array($existing_user, $UserList)) {
+						$sql = "DELETE FROM $tbl_session_rel_course_rel_user WHERE id_session='$id_session' AND course_code='$enreg_course' AND id_user='$existing_user'";
+						api_sql_query($sql,__FILE__,__LINE__);
+	
+						if(Database::affected_rows()) {
+							$nbr_users--;
+						}
+					}
+				}
+			}
+			// insert new users into session_rel_course_rel_user and ignore if they already exist
+			foreach ($UserList as $enreg_user) {
+				if(!in_array($enreg_user, $existingUsers)) {
+	                   $enreg_user = Database::escape_string($enreg_user);
+					$insert_sql = "INSERT IGNORE INTO $tbl_session_rel_course_rel_user(id_session,course_code,id_user) VALUES('$id_session','$enreg_course','$enreg_user')";
+					api_sql_query($insert_sql,__FILE__,__LINE__);
+						if(Database::affected_rows()) {
+						$nbr_users++;
+					}
+				}
+			}
+			// count users in this session-course relation
+			$sql = "SELECT COUNT(id_user) as nbUsers FROM $tbl_session_rel_course_rel_user WHERE id_session='$id_session' AND course_code='$enreg_course'";
+			$rs = api_sql_query($sql, __FILE__, __LINE__);
+			list($nbr_users) = Database::fetch_array($rs);
+			// update the session-course relation to add the users total
+			$update_sql = "UPDATE $tbl_session_rel_course SET nbr_users=$nbr_users WHERE id_session='$id_session' AND course_code='$enreg_course'";
+			api_sql_query($update_sql,__FILE__,__LINE__);
+			}
+			// delete users from the session
+		if ($empty_users!==false){
+			api_sql_query("DELETE FROM $tbl_session_rel_user WHERE id_session = $id_session",__FILE__,__LINE__);
+		}
+			// insert missing users into session
+		$nbr_users = 0;
+		foreach ($UserList as $enreg_user) {
+	        $enreg_user = Database::escape_string($enreg_user);
+			$nbr_users++;
+			$insert_sql = "INSERT IGNORE INTO $tbl_session_rel_user(id_session, id_user) VALUES('$id_session','$enreg_user')";
+			api_sql_query($insert_sql,__FILE__,__LINE__);
+		}
+		// update number of users in the session
+		$nbr_users = count($UserList);
+		$update_sql = "UPDATE $tbl_session SET nbr_users= $nbr_users WHERE id='$id_session' ";
+		api_sql_query($update_sql,__FILE__,__LINE__);
+	}
+	 /**Subscribes courses to the given session and optionally (default) unsubscribes previous users
+	 * @author Carlos Vargas <carlos.vargas@dokeos.com>,
+     * @param	int		Session ID
+     * @param	array	List of courses IDs
+     * @param	bool	Whether to unsubscribe existing users (true, default) or not (false)
+     * @return	void	Nothing, or false on error  
+     */
+     function add_courses_to_session($id_session, $CourseList, $empty_courses=true){
+     	
+     	if ($id_session!= strval(intval($id_session))) return false;
+	   	foreach($CourseList as $intCourse){
+	   		if ($intCourse!= strval(intval($intCourse))) return false;
+	   	}
+		$tbl_session_rel_course_rel_user	= Database::get_main_table(TABLE_MAIN_SESSION_COURSE_USER);
+		$tbl_session						= Database::get_main_table(TABLE_MAIN_SESSION);
+		$tbl_session_rel_user				= Database::get_main_table(TABLE_MAIN_SESSION_USER);
+		$tbl_session_rel_course				= Database::get_main_table(TABLE_MAIN_SESSION_COURSE);
+		$tbl_course							= Database::get_main_table(TABLE_MAIN_COURSE);
+     	
+		$id_coach = api_sql_query("SELECT id_coach FROM $tbl_session WHERE id=$id_session");
+		$id_coach = Database::fetch_array($id_coach);
+		$id_coach = $id_coach[0];
+	
+		$rs = api_sql_query("SELECT course_code FROM $tbl_session_rel_course WHERE id_session=$id_session");
+		$existingCourses = api_store_result($rs);
+	
+		$sql="SELECT id_user
+			FROM $tbl_session_rel_user
+			WHERE id_session = $id_session";
+		$result=api_sql_query($sql,__FILE__,__LINE__);
+		$UserList=api_store_result($result);
+	
+	
+		foreach($CourseList as $enreg_course) {
+			$enreg_course = Database::escape_string($enreg_course);
+			$exists = false;
+			foreach($existingCourses as $existingCourse) {
+				if($enreg_course == $existingCourse['course_code']) {
+					$exists=true;
+				}
+			}
+			if(!$exists) {			
+				$sql_insert_rel_course= "INSERT INTO $tbl_session_rel_course(id_session,course_code, id_coach) VALUES('$id_session','$enreg_course','$id_coach')";
+				api_sql_query($sql_insert_rel_course ,__FILE__,__LINE__);			
+				//We add in the existing courses table the current course, to not try to add another time the current course
+				$existingCourses[]=array('course_code'=>$enreg_course);
+				$nbr_users=0;
+				foreach ($UserList as $enreg_user) {				
+					$enreg_user = Database::escape_string($enreg_user['id_user']);
+					$sql_insert = "INSERT IGNORE INTO $tbl_session_rel_course_rel_user(id_session,course_code,id_user) VALUES('$id_session','$enreg_course','$enreg_user')";
+					api_sql_query($sql_insert,__FILE__,__LINE__);
+					if(Database::affected_rows()) {
+						$nbr_users++;
+					}
+				}
+				api_sql_query("UPDATE $tbl_session_rel_course SET nbr_users=$nbr_users WHERE id_session='$id_session' AND course_code='$enreg_course'",__FILE__,__LINE__);
+			}
+	
+		}
+		if ($empty_courses!==false) {
+			foreach($existingCourses as $existingCourse) {
+				if(!in_array($existingCourse['course_code'], $CourseList)){
+					api_sql_query("DELETE FROM $tbl_session_rel_course WHERE course_code='".$existingCourse['course_code']."' AND id_session=$id_session");
+					api_sql_query("DELETE FROM $tbl_session_rel_course_rel_user WHERE course_code='".$existingCourse['course_code']."' AND id_session=$id_session");
+		
+				}
+			}
+		}
+		$nbr_courses=count($CourseList);
+		api_sql_query("UPDATE $tbl_session SET nbr_courses=$nbr_courses WHERE id='$id_session'",__FILE__,__LINE__);
+     }
+}
+?>