main_api.lib.php

完美的在线教育系统

			break;
	}
}

/**
* This function returns the id of the user which is stored in the $_user array.
*
* @example The function can be used to check if a user is logged in
* 			if (api_get_user_id())
* @return integer the id of the current user
*/
function api_get_user_id()
{
	if(empty($GLOBALS['_user']['user_id']))
	{
		return 0;
	}
	return $GLOBALS['_user']['user_id'];
}
/**
 * @param $user_id (integer): the id of the user
 * @return $user_info (array): user_id, lastname, firstname, username, email, ...
 * @author Patrick Cool <[e-mail]>
 * @version 21 September 2004
 * @desc find all the information about a user. If no paramater is passed you find all the information about the current user.
*/
function api_get_user_info($user_id = '')
{
	global $tbl_user;
	if ($user_id == '')
	{
		return $GLOBALS["_user"];
	}
	else
	{
		$sql = "SELECT * FROM ".Database :: get_main_table(TABLE_MAIN_USER)." WHERE user_id='".mysql_real_escape_string($user_id)."'";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		if(mysql_num_rows($result) > 0)
		{
			$result_array = mysql_fetch_array($result);
			// this is done so that it returns the same array-index-names
			// ideally the names of the fields of the user table are renamed so that they match $_user (or vice versa)
			// $_user should also contain every field of the user table (except password maybe). This would make the
			// following lines obsolete (and the code cleaner and slimmer !!!
			$user_info['firstName'] = $result_array['firstname'];
			$user_info['lastName'] = $result_array['lastname'];
			$user_info['mail'] = $result_array['email'];
			$user_info['picture_uri'] = $result_array['picture_uri'];
			$user_info['user_id'] = $result_array['user_id'];
			$user_info['official_code'] = $result_array['official_code'];
			$user_info['status'] = $result_array['status'];
			$user_info['auth_source'] = $result_array['auth_source'];
			$user_info['username'] = $result_array['username'];
			$user_info['theme'] = $result_array['theme'];
			return $user_info;
		}
		return false;
	}
}
/**
 * Returns the current course id (integer)
*/
function api_get_course_id()
{
	return $GLOBALS["_cid"];
}
/**
 * Returns the current course directory
 *
 * This function relies on api_get_course_info()
 * @param	string	The course code - optional (takes it from session if not given)
 * @return	string	The directory where the course is located inside the Dokeos "courses" directory
 * @author	Yannick Warnier <[e-mail]>
*/
function api_get_course_path($course_code=null)
{
	if(!empty($course_code))
	{
		$info = api_get_course_info($course_code);
	}
	else
	{
		$info = api_get_course_info();
	}
	return $info['path'];
}
/**
 * Gets a course setting from the current course_setting table. Try always using integer values.
 * @param	string	The name of the setting we want from the table
 * @return	mixed	The value of that setting in that table. Return -1 if not found.
 */
function api_get_course_setting($setting_name)
{
	$table = Database::get_course_table(TABLE_COURSE_SETTING);
	$setting_name = mysql_real_escape_string($setting_name);
	$sql = "SELECT * FROM $table WHERE variable = '$setting_name'";
	$res = api_sql_query($sql,__FILE__,__LINE__);
	if(Database::num_rows($res)>0){
		$row = Database::fetch_array($res);
		return $row['value'];
	}
	return -1;
}
/**
 * Gets an anonymous user ID
 * 
 * For some tools that need tracking, like the learnpath tool, it is necessary
 * to have a usable user-id to enable some kind of tracking, even if not
 * perfect. An anonymous ID is taken from the users table by looking for a
 * status of "6" (anonymous).
 * @return	int	User ID of the anonymous user, or O if no anonymous user found
 */
function api_get_anonymous_id()
{
	$table = Database::get_main_table(TABLE_MAIN_USER);
	$sql = "SELECT user_id FROM $table WHERE status = 6";
	$res = api_sql_query($sql,__FILE__,__LINE__);
	if(Database::num_rows($res)>0)
	{
		$row = Database::fetch_array($res);
		//error_log('api_get_anonymous_id() returns '.$row['user_id'],0);
		return $row['user_id'];
	}
	else //no anonymous user was found
	{
		return 0;
	}
}

/**
 * Returns the cidreq parameter name + current course id
*/
function api_get_cidreq()
{
	if (!empty ($GLOBALS["_cid"]))
	{
		return 'cidReq='.htmlspecialchars($GLOBALS["_cid"]);
	}
	return '';
}
/**
*	Returns the current course info array.
*	Note: this array is only defined if the user is inside a course.
*	Array elements:
*	['name']
*	['official_code']
*	['sysCode']
*	['path']
*	['dbName']
*	['dbNameGlu']
*	['titular']
*	['language']
*	['extLink']['url' ]
*	['extLink']['name']
*	['categoryCode']
*	['categoryName']
*	Now if the course_code is given, the returned array gives info about that
*   particular course, not specially the current one.
* @todo	same behaviour as api_get_user_info so that api_get_course_id becomes absolete too
*/
function api_get_course_info($course_code=null)
{
	if(!empty($course_code))
	{
		$course_code = Database::escape_string($course_code);
		$course_table = Database::get_main_table(TABLE_MAIN_COURSE);
    	$course_cat_table = Database::get_main_table(TABLE_MAIN_CATEGORY);
        $sql =    "SELECT `course`.*, `course_category`.`code` `faCode`, `course_category`.`name` `faName`
                 FROM $course_table
                 LEFT JOIN $course_cat_table
                 ON `course`.`category_code` =  `course_category`.`code`
                 WHERE `course`.`code` = '$course_code'";
        $result = api_sql_query($sql,__FILE__,__LINE__);
        $_course = array();
        if (Database::num_rows($result)>0)
        {
        	global $_configuration;
            $cData = Database::fetch_array($result);
			$_course['id'          ]         = $cData['code'             ]; //auto-assigned integer
			$_course['name'        ]         = $cData['title'         ];
            $_course['official_code']         = $cData['visual_code'        ]; // use in echo
            $_course['sysCode'     ]         = $cData['code'             ]; // use as key in db
            $_course['path'        ]         = $cData['directory'        ]; // use as key in path
            $_course['dbName'      ]         = $cData['db_name'           ]; // use as key in db list
            $_course['dbNameGlu'   ]         = $_configuration['table_prefix'] . $cData['db_name'] . $_configuration['db_glue']; // use in all queries
            $_course['titular'     ]         = $cData['tutor_name'       ];
            $_course['language'    ]         = $cData['course_language'   ];
            $_course['extLink'     ]['url' ] = $cData['department_url'    ];
            $_course['extLink'     ]['name'] = $cData['department_name'];
            $_course['categoryCode']         = $cData['faCode'           ];
            $_course['categoryName']         = $cData['faName'           ];

            $_course['visibility'  ]         = $cData['visibility'];
            $_course['subscribe_allowed']    = $cData['subscribe'];
			$_course['unubscribe_allowed']   = $cData['unsubscribe'];
        }
        return $_course;			
	}
	else
	{
		global $_course;
		return $_course;
	}
}

/*
==============================================================================
		DATABASE QUERY MANAGEMENT
==============================================================================
*/
/**
 * Executes an SQL query
 * You have to use addslashes() on each value that you want to record into the database
 *
 * @author Olivier Brouckaert
 * @param  string $query - SQL query
 * @param  string $file - optional, the file path and name of the error (__FILE__)
 * @param  string $line - optional, the line of the error (__LINE__)
 * @return resource - the return value of the query
 */
function api_sql_query($query, $file = '', $line = 0)
{
	$result = @mysql_query($query);

	if ($line && !$result)
	{
			$info = '<pre>';
			$info .= '<b>MYSQL ERROR :</b><br/> ';
			$info .= mysql_error();
			$info .= '<br/>';
			$info .= '<b>QUERY       :</b><br/> ';
			$info .= $query;
			$info .= '<br/>';
			$info .= '<b>FILE        :</b><br/> ';
			$info .= ($file == '' ? ' unknown ' : $file);
			$info .= '<br/>';
			$info .= '<b>LINE        :</b><br/> ';
			$info .= ($line == 0 ? ' unknown ' : $line);
			$info .= '</pre>';
			//@ mysql_close();
			//die($info);
			echo $info;
	}
	return $result;
}
/**
 * Store the result of a query into an array
 *
 * @author Olivier Brouckaert
 * @param  resource $result - the return value of the query
 * @return array - the value returned by the query
 */
function api_store_result($result)
{
	$tab = array ();
	while ($row = mysql_fetch_array($result))
	{
		$tab[] = $row;
	}
	return $tab;
}

/*
==============================================================================
		SESSION MANAGEMENT
==============================================================================
*/
/**
 * Start the Dokeos session.
 * 
 * The default lifetime for session is set here. It is not possible to have it
 * as a database setting as it is used before the database connection has been made.
 * It is taken from the configuration file, and if it doesn't exist there, it is set
 * to 360000 seconds
 *
 * @author Olivier Brouckaert
 * @param  string variable - the variable name to save into the session
 */
function api_session_start($already_installed = true)
{
	global $storeSessionInDb;
	global $_configuration;
	
	/* causes too many problems and is not configurable dynamically
	 * 
	if($already_installed){
		$session_lifetime = 360000;
		if(isset($_configuration['session_lifetime']))
		{
			$session_lifetime = $_configuration['session_lifetime'];	
		}
		session_set_cookie_params($session_lifetime,api_get_path(REL_PATH));
		
	}*/
	if (is_null($storeSessionInDb))
	{
		$storeSessionInDb = false;
	}
	if ($storeSessionInDb && function_exists('session_set_save_handler'))
	{
		include_once (api_get_path(LIBRARY_PATH).'session_handler.class.php');
		$session_handler = new session_handler();
		@ session_set_save_handler(array (& $session_handler, 'open'), array (& $session_handler, 'close'), array (& $session_handler, 'read'), array (& $session_handler, 'write'), array (& $session_handler, 'destroy'), array (& $session_handler, 'garbage'));
	}
	session_name('dk_sid');
	session_start();
	if ($already_installed)
	{
		if (empty ($_SESSION['checkDokeosURL']))
		{
			$_SESSION['checkDokeosURL'] = api_get_path(WEB_PATH);
		}
		elseif ($_SESSION['checkDokeosURL'] != api_get_path(WEB_PATH))
		{
			api_session_clear();
		}
	}
}
/**
 * save a variable into the session
 *
 * BUG: function works only with global variables
 *
 * @author Olivier Brouckaert
 * @param  string variable - the variable name to save into the session
 */
function api_session_register($variable)
{
	global $$variable;
	session_register($variable);
	$_SESSION[$variable] = $$variable;
}
/**
 * Remove a variable from the session.
 *
 * @author Olivier Brouckaert
 * @param  string variable - the variable name to remove from the session
 */
function api_session_unregister($variable)
{
	if(isset($GLOBALS[$variable]))
	{
		unset ($GLOBALS[$variable]);
	}
	
	if(isset($_SESSION[$variable]))
	{
		$_SESSION[$variable] = null;
		session_unregister($variable);		
	}	
}
/**
 * Clear the session
 *
 * @author Olivier Brouckaert
 */
function api_session_clear()
{
	session_regenerate_id();
	session_unset();
	$_SESSION = array ();
}
/**
 * Destroy the session
 *
 * @author Olivier Brouckaert
 */
function api_session_destroy()
{
	session_unset();
	$_SESSION = array ();
	session_destroy();
}

/*
==============================================================================
		STRING MANAGEMENT
==============================================================================
*/
function api_add_url_param($url, $param)
{
	if (empty ($param))
	{
		return $url;
	}
	if (strstr($url, '?'))
	{
		if ($param[0] != '&')
		{
			$param = '&'.$param;
		}
		list (, $query_string) = explode('?', $url);
		$param_list1 = explode('&', $param);
		$param_list2 = explode('&', $query_string);
		$param_list1_keys = $param_list1_vals = array ();
		foreach ($param_list1 as $key => $enreg)
		{
			list ($param_list1_keys[$key], $param_list1_vals[$key]) = explode('=', $enreg);
		}
		$param_list1 = array ('keys' => $param_list1_keys, 'vals' => $param_list1_vals);
		foreach ($param_list2 as $enreg)
		{
			$enreg = explode('=', $enreg);
			$key = array_search($enreg[0], $param_list1['keys']);
			if (!is_null($key) && !is_bool($key))
			{
				$url = str_replace($enreg[0].'='.$enreg[1], $enreg[0].'='.$param_list1['vals'][$key], $url);
				$param = str_replace('&'.$enreg[0].'='.$param_list1['vals'][$key], '', $param);
			}
		}
		$url .= $param;
	}
	else
	{
		$url = $url.'?'.$param;
	}