groupmanager.lib.php

完美的在线教育系统

	}
	/**
	 * Unsubscribe all tutors from one or more groups
	 * @param mixed $group_id Can be an array with group-id's or a single group-id
	 * @see unsubscribe_all_users. This function is almost an exact copy of that function.
	 * @return bool TRUE if successfull
	 * @author Patrick Cool <[e-mail]>, Ghent University
	 */
	function unsubscribe_all_tutors($group_ids)
	{
		$group_ids = is_array($group_ids) ? $group_ids : array ($group_ids);
		if( count($group_ids) > 0)
		{
			$table_group_tutor = Database :: get_course_table(TABLE_GROUP_TUTOR);
			$sql = 'DELETE FROM '.$table_group_tutor.' WHERE group_id IN ('.implode(',', $group_ids).')';
			$result = api_sql_query($sql,__FILE__,__LINE__);
			return $result;
		}
		return true;
	}

	/**
	 * Is the user a tutor of this group?
	 * @param $user_id the id of the user
	 * @param $group_id the id of the group
	 * @return boolean true/false
	 * @author Patrick Cool <[e-mail]>, Ghent University
	 */
	function is_tutor_of_group($user_id,$group_id)
	{
		global $_course;

		$table_group_tutor = Database :: get_course_table(TABLE_GROUP_TUTOR);
		$sql = "SELECT * FROM ".$table_group_tutor." WHERE user_id='".$user_id."' AND group_id='".$group_id."'";
		$result = api_sql_query($sql,__FILE__,__LINE__);
		if (mysql_num_rows($result)>0)
		{
			return true;
		}
		else
		{
			return false;
		}
	}

	/**
	 * Is the user part of this group? This can be a tutor or a normal member
	 * you should use this function if the access to a tool or functionality is restricted to the people who are actually in the group
	 * before you had to check if the user was 1. a member of the group OR 2. a tutor of the group. This function combines both
	 * @param $user_id the id of the user
	 * @param $group_id the id of the group
	 * @return boolean true/false
	 * @author Patrick Cool <[e-mail]>, Ghent University
	*/
	function is_user_in_group($user_id, $group_id)
	{
		$member = GroupManager :: is_subscribed($user_id,$group_id);
		$tutor  = GroupManager :: is_tutor_of_group($user_id,$group_id);

		if ($member OR $tutor)
		{
			return true;
		}
		else
		{
			return false;
		}
	}



	/**
	 * Get all tutors for the current course.
	 * @return array An array with firstname, lastname and user_id for all
	 *               tutors in the current course.
	 * @deprecated this function uses the old tutor implementation
	 */
	function get_all_tutors()
	{
		global $_course;
		$course_user_table = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
		$user_table = Database :: get_main_table(TABLE_MAIN_USER);
		$sql = "SELECT user.user_id AS user_id, user.lastname AS lastname, user.firstname AS firstname
				FROM ".$user_table." user, ".$course_user_table." cu
				WHERE cu.user_id=user.user_id
				AND cu.tutor_id='1'
				AND cu.course_code='".$_course['sysCode']."'";
		$resultTutor = api_sql_query($sql,__FILE__,__LINE__);
		$tutors = array ();
		while ($tutor = mysql_fetch_array($resultTutor))
		{
			$tutors[] = $tutor;
		}
		return $tutors;
	}


	/**
	 * Is user a tutor in current course
	 * @param int $user_id
	 * @return bool TRUE if given user is a tutor in the current course.
	 * @deprecated this function uses the old tutor implementation
	 */
	function is_tutor($user_id)
	{
		global $_course;
		$course_user_table = Database :: get_main_table(TABLE_MAIN_COURSE_USER);
		$sql = "SELECT tutor_id FROM ".$course_user_table."
		             WHERE `user_id`='".$user_id."'
		             AND `course_code`='".$_course['sysCode']."'"."AND tutor_id=1";
		$db_result = api_sql_query($sql,__FILE__,__LINE__);
		$result = (mysql_num_rows($db_result) > 0);
		return $result;
	}

	/**
	 * Get all group's from a given course in which a given user is ubscribed
	 * @author  Patrick Cool
	 * @param	 string $course_db: the database of the course you want to
	 * retrieve the groups for
	 * @param integer $user_id: the ID of the user you want to know all its
	 * group memberships
	 */
	function get_group_ids($course_db,$user_id)
	{
	$groups = array();
	$tbl_group = Database::get_course_table(TABLE_GROUP_USER,$course_db);

	$sql = "SELECT group_id FROM $tbl_group WHERE user_id = '$user_id'";
	$groupres = api_sql_query($sql);

	// uncommenting causes a bug in Agenda AND announcements because there we check if the return value of this function is an array or not
	//$groups=array();

	if($groupres)
	{
		while ($myrow= mysql_fetch_array($groupres))
			$groups[]=$myrow['group_id'];
	}

	return $groups;
	}
	/*
	-----------------------------------------------------------
	Group functions
	these take virtual/linked courses into account when necessary
	-----------------------------------------------------------
	*/
	/**
	*	Get a combined list of all users of the real course $course_code
	*		and all users in virtual courses linked to this course $course_code
	*	Filter user list: remove duplicate users; plus
	*		remove users that
	*		- are already in the current group $group_id;
	*		- do not have student status in these courses;
	*		- are not appointed as tutor (group assistent) for this group;
	*		- have already reached their maximum # of groups in this course.
	*
	*	Originally to get the correct list of users a big SQL statement was used,
	*	but this has become more complicated now there is not just one real course but many virtual courses.
	*	Still, that could have worked as well.
	*
	*	@version 1.1.3
	*	@author Roan Embrechts
	*/
	function get_complete_list_of_users_that_can_be_added_to_group($course_code, $group_id)
	{
		global $_course, $_user;
		$category = GroupManager :: get_category_from_group($group_id, $course_code);
		$number_of_groups_limit = $category['groups_per_user'] == GROUP_PER_MEMBER_NO_LIMIT ? INFINITE : $category['groups_per_user'];
		$real_course_code = $_course['sysCode'];
		$real_course_info = Database :: get_course_info($real_course_code);
		$real_course_user_list = CourseManager :: get_user_list_from_course_code($virtual_course_code);
		//get list of all virtual courses
		$user_subscribed_course_list = CourseManager :: get_list_of_virtual_courses_for_specific_user_and_real_course($_user['user_id'], $real_course_code);
		//add real course to the list
		$user_subscribed_course_list[] = $real_course_info;
		if (!is_array($user_subscribed_course_list))
			return;
		//for all courses...
		foreach ($user_subscribed_course_list as $this_course)
		{
			$this_course_code = $this_course["code"];
			$course_user_list = CourseManager :: get_user_list_from_course_code($this_course_code);
			//for all users in the course
			foreach ($course_user_list as $this_user)
			{
				$user_id = $this_user["user_id"];
				$loginname = $this_user["username"];
				$lastname = $this_user["lastname"];
				$firstname = $this_user["firstname"];
				$status = $this_user["status"];
				//$role =  $this_user["role"];
				$tutor_id = $this_user["tutor_id"];
				$full_name = $lastname.", ".$firstname;
				if ($lastname == "" || $firstname == '')
					$full_name = $loginname;
				$complete_user["user_id"] = $user_id;
				$complete_user["full_name"] = $full_name;
				$complete_user['firstname'] = $firstname;
				$complete_user['lastname'] = $lastname;
				$complete_user["status"] = $status;
				$complete_user["tutor_id"] = $tutor_id;
				$student_number_of_groups = GroupManager :: user_in_number_of_groups($user_id, $category['id']);
				//filter: only add users that have not exceeded their maximum amount of groups
				if ($student_number_of_groups < $number_of_groups_limit)
				{
					$complete_user_list[] = $complete_user;
				}
			}
		}
		if (is_array($complete_user_list))
		{
			//sort once, on array field "full_name"
			$complete_user_list = TableSort :: sort_table($complete_user_list, "full_name");
			//filter out duplicates, based on field "user_id"
			$complete_user_list = GroupManager :: filter_duplicates($complete_user_list, "user_id");
			$complete_user_list = GroupManager :: filter_users_already_in_group($complete_user_list, $group_id);
			//$complete_user_list = GroupManager :: filter_only_students($complete_user_list);
		}
		return $complete_user_list;
	}
	/**
	*	Filter out duplicates in a multidimensional array
	*	by comparing field $compare_field.
	*
	*	@param $user_array_in list of users (must be sorted).
	*	@param string $compare_field, the field to be compared
	*/
	function filter_duplicates($user_array_in, $compare_field)
	{
		$total_number = count($user_array_in);
		$user_array_out[0] = $user_array_in[0];
		$count_out = 0;
		for ($count_in = 1; $count_in < $total_number; $count_in ++)
		{
			if ($user_array_in[$count_in][$compare_field] != $user_array_out[$count_out][$compare_field])
			{
				$count_out ++;
				$user_array_out[$count_out] = $user_array_in[$count_in];
			}
		}
		return $user_array_out;
	}
	/**
	*	Filters from the array $user_array_in the users already in the group $group_id.
	*/
	function filter_users_already_in_group($user_array_in, $group_id)
	{
		foreach ($user_array_in as $this_user)
		{
			if (!GroupManager :: is_subscribed($this_user['user_id'], $group_id))
			{
				$user_array_out[] = $this_user;
			}
		}
		return $user_array_out;
	}
	/**
	* Remove all users that are not students and all users who have tutor status
	* from  the list.
	*/
	function filter_only_students($user_array_in)
	{
		$user_array_out = array ();
		foreach ($user_array_in as $this_user)
		{
			if ($this_user['status'] == STUDENT && $this_user['tutor_id'] == 0)
			{
				$user_array_out[] = $this_user;
			}
		}
		return $user_array_out;
	}
	/**
	 * Check if a user has access to a certain group tool
	 * @param int $user_id The user id
	 * @param int $group_id The group id
	 * @param constant $tool The tool to check the access rights. This should be
	 * one of constants: GROUP_TOOL_DOCUMENTS
	 * @return bool True if the given user has access to the given tool in the
	 * given course.
	 */
	function user_has_access($user_id, $group_id, $tool)
	{
		switch ($tool)
		{
			case GROUP_TOOL_DOCUMENTS :
				$state_key = 'doc_state';
				break;
			case GROUP_TOOL_CALENDAR :
				$state_key = 'calendar_state';
				break;
			case GROUP_TOOL_ANNOUNCEMENT :
				$state_key = 'announcements_state';
				break;
			case GROUP_TOOL_WORK :
				$state_key = 'work_state';
				break;	
			default:
				return false;
		}
		$group = GroupManager :: get_group_properties($group_id);
		if ($group[$state_key] == TOOL_NOT_AVAILABLE)
		{
			return false;
		}
		elseif ($group[$state_key] == TOOL_PUBLIC)
		{
			return true;
		}
		elseif (api_is_allowed_to_edit())
		{
			return true;
		}
		elseif($group['tutor_id'] == $user_id)
		{
			return true;
		}
		else
		{
			return GroupManager :: is_subscribed($user_id, $group_id);
		}
	}
	/**
	 * Get all groups where a specific user is subscribed
	 */
	function get_user_group_name($user_id){
		
		$table_group_user=Database::get_course_table(TABLE_GROUP_USER);
		$table_group=Database::get_course_table(TABLE_GROUP);
		
		$sql_groups = 'SELECT name FROM '.$table_group.' g,'.$table_group_user.' gu WHERE gu.user_id="'.$user_id.'" AND gu.group_id=g.id';
		$res = api_sql_query($sql_groups,__FILE__,__LINE__);
		
		$groups=array();
	    while($group = mysql_fetch_array($res))
	    {
	    	$groups[] .= $group['name'];
	    }
	    return $groups;
	}
}
?>