main_api.lib.php

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	return $url;
}
/**
* Returns a difficult to guess password.
* @param int $length, the length of the password
* @return string the generated password
*/
function api_generate_password($length = 8)
{
	$characters = 'abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789';
	if ($length < 2)
	{
		$length = 2;
	}
	$password = '';
	for ($i = 0; $i < $length; $i ++)
	{
		$password .= $characters[rand() % strlen($characters)];
	}
	return $password;
}
/**
* Checks a password to see wether it is OK to use.
* @param string $password
* @return true if the password is acceptable, false otherwise
*/
function api_check_password($password)
{
	$lengthPass = strlen($password);
	if ($lengthPass < 5)
	{
		return false;
	}
	$passLower = strtolower($password);
	$cptLettres = $cptChiffres = 0;
	$consecutif = 0;
	$codeCharPrev = 0;
	for ($i = 0; $i < $lengthPass; $i ++)
	{
		$codeCharCur = ord($passLower[$i]);
		if ($i && abs($codeCharCur - $codeCharPrev) <= 1)
		{
			$consecutif ++;
			if ($consecutif == 3)
			{
				return false;
			}
		}
		else
		{
			$consecutif = 1;
		}
		if ($codeCharCur >= 97 && $codeCharCur <= 122)
		{
			$cptLettres ++;
		}
		elseif ($codeCharCur >= 48 && $codeCharCur <= 57)
		{
			$cptChiffres ++;
		}
		else
		{
			return false;
		}
		$codeCharPrev = $codeCharCur;
	}
	return ($cptLettres >= 3 && $cptChiffres >= 2) ? true : false;
}
/**
 * Clear the user ID from the session if it was the anonymous user. Generally
 * used on out-of-tools pages to remove a user ID that could otherwise be used
 * in the wrong context.
 * This function is to be used in conjunction with the api_set_anonymous()
 * function to simulate the user existence in case of an anonymous visit.
 * @param	bool	database check switch - passed to api_is_anonymous()
 * @return	bool	true if succesfully unregistered, false if not anonymous. 
 */
function api_clear_anonymous($db_check=false)
{
	global $_user;
	if(api_is_anonymous($_user['user_id'],$db_check))
	{
		unset($_user['user_id']);
		api_session_unregister('_uid');
		return true;
	}
	else
	{
		return false;
	}
}

/**
 * truncates a string
 *
 * @author Brouckaert Olivier
 * @param  string text - text to truncate
 * @param  integer length - length of the truncated text
 * @param  string endStr - suffix
 * @param  boolean middle - if true, truncates on string middle
 */
function api_trunc_str($text, $length = 30, $endStr = '...', $middle = false)
{
	if (strlen($text) <= $length)
	{
		return $text;
	}
	if ($middle)
	{
		$text = rtrim(substr($text, 0, round($length / 2))).$endStr.ltrim(substr($text, -round($length / 2)));
	}
	else
	{
		$text = rtrim(substr($text, 0, $length)).$endStr;
	}
	return $text;
}
// deprecated, use api_trunc_str() instead
function shorten($input, $length = 15)
{
	$length = intval($length);
	if (!$length)
	{
		$length = 15;
	}
	return api_trunc_str($input, $length);
}
/**
 * handling simple and double apostrofe in order that strings be stored properly in database
 *
 * @author Denes Nagy
 * @param  string variable - the variable to be revised
 */
function domesticate($input)
{
	$input = stripslashes($input);
	$input = str_replace("'", "''", $input);
	$input = str_replace('"', "''", $input);
	return ($input);
}

/*
==============================================================================
		FAILURE MANAGEMENT
==============================================================================
*/

/*
 * The Failure Management module is here to compensate
 * the absence of an 'exception' device in PHP 4.
 */
/**
 * $api_failureList - array containing all the failure recorded
 * in order of arrival.
 */
$api_failureList = array ();
/**
 * Fills a global array called $api_failureList
 * This array collects all the failure occuring during the script runs
 * The main purpose is allowing to manage the display messages externaly
 * from the functions or objects. This strengthens encupsalation principle
 *
 * @author Hugues Peeters <[e-mail]>
 * @param  string $failureType - the type of failure
 * @global array $api_failureList
 * @return bolean false to stay consistent with the main script
 */
function api_set_failure($failureType)
{
	global $api_failureList;
	$api_failureList[] = $failureType;
	return false;
}

/**
 * Sets the current user as anonymous if it hasn't been identified yet. This 
 * function should be used inside a tool only. The function api_clear_anonymous()
 * acts in the opposite direction by clearing the anonymous user's data every
 * time we get on a course homepage or on a neutral page (index, admin, my space)
 * @return	bool	true if set user as anonymous, false if user was already logged in or anonymous id could not be found
 */
function api_set_anonymous()
{
	global $_user;
	if(!empty($_user['user_id']))
	{
		return false;
	}
	else
	{
		$user_id = api_get_anonymous_id();
		if($user_id == 0)
		{
			return false;
		}
		else
		{
			api_session_unregister('_user');
			$_user['user_id'] = $user_id;
			$_user['is_anonymous'] = true;
			api_session_register('_user');
			$GLOBALS['_user'] = $_user;
			return true;
		}
	}
}

/**
 * get the last failure stored in $api_failureList;
 *
 * @author Hugues Peeters <[e-mail]>
 * @param void
 * @return string - the last failure stored
 */
function api_get_last_failure()
{
	global $api_failureList;
	return $api_failureList[count($api_failureList) - 1];
}
/**
 * collects and manage failures occuring during script execution
 * The main purpose is allowing to manage the display messages externaly
 * from functions or objects. This strengthens encupsalation principle
 *
 * @author Hugues Peeters <[e-mail]>
 * @package dokeos.library
 */
class api_failure
{
	/*
	 * IMPLEMENTATION NOTE : For now the $api_failureList list is set to the
	 * global scope, as PHP 4 is unable to manage static variable in class. But
	 * this feature is awaited in PHP 5. The class is already written to minize
	 * the change when static class variable will be possible. And the API won't
	 * change.
	 */
	public $api_failureList = array ();
	/**
	 * Pile the last failure in the failure list
	 *
	 * @author Hugues Peeters <[e-mail]>
	 * @param  string $failureType - the type of failure
	 * @global array  $api_failureList
	 * @return bolean false to stay consistent with the main script
	 */
	function set_failure($failureType)
	{
		global $api_failureList;
		$api_failureList[] = $failureType;
		return false;
	}
	/**
	 * get the last failure stored
	 *
	 * @author Hugues Peeters <[e-mail]>
	 * @param void
	 * @return string - the last failure stored
	 */
	function get_last_failure()
	{
		global $api_failureList;
		return $api_failureList[count($api_failureList) - 1];
	}
}

/*
==============================================================================
		CONFIGURATION SETTINGS
==============================================================================
*/
/**
* DEPRECATED, use api_get_setting instead
*/
function get_setting($variable, $key = NULL)
{
	global $_setting;
	return api_get_setting($variable, $key);
}


/**
* Returns the value of a setting from the web-adjustable admin config settings.
*
* WARNING true/false are stored as string, so when comparing you need to check e.g.
* if(api_get_setting("show_navigation_menu") == "true") //CORRECT
* instead of
* if(api_get_setting("show_navigation_menu") == true) //INCORRECT
* @param	string	The variable name
* @param	string	The subkey (sub-variable) if any. Defaults to NULL
* @author Rene Haentjens
* @author Bart Mollet
*/
function api_get_setting($variable, $key = NULL)
{
	global $_setting;
	return is_null($key) ? (!empty($_setting[$variable])?$_setting[$variable]:null) : $_setting[$variable][$key];
}

/**
 * Returns an escaped version of $_SERVER['PHP_SELF'] to avoid XSS injection
 * @return	string	Escaped version of $_SERVER['PHP_SELF']
 */
function api_get_self()
{
	return htmlentities($_SERVER['PHP_SELF']);
}

/*
==============================================================================
		LANGUAGE SUPPORT
==============================================================================
*/

/**
* Whenever the server type in the Dokeos Config settings is
* set to test/development server you will get an indication that a language variable
* is not translated and a link to a suggestions form of DLTT.
*
* @return language variable '$lang'.$variable or language variable $variable.
*
* @author Roan Embrechts
* @author Patrick Cool
*/
function get_lang($variable, $notrans = 'DLTT')
{
	$ot = '[='; //opening tag for missing vars
	$ct = '=]'; //closing tag for missing vars
	if(api_get_setting('hide_dltt_markup') == 'true')
	{
		$ot = '';
		$ct = '';
	}
	if (api_get_setting('server_type') != 'test')
	{
		$lvv = isset ($GLOBALS['lang'.$variable]) ? $GLOBALS['lang'.$variable] : (isset ($GLOBALS[$variable]) ? $GLOBALS[$variable] : $ot.$variable.$ct);
		if (!is_string($lvv))
			return $lvv;
		return str_replace("\\'", "'", $lvv);
	}
	if (!is_string($variable))
		return $ot.'get_lang(?)'.$ct;
	global $language_interface, $language_files;
	//language file specified in tool
    $langpath = api_get_path(SYS_CODE_PATH).'lang/';
	if (isset ($language_files))
	{
		if (!is_array($language_files))
		{
			@include ($langpath.$language_interface.'/'.$language_files.'.inc.php');
		}
		else
		{
			foreach ($language_files as $index => $language_file)
			{
				@include ($langpath.$language_interface.'/'.$language_file.'.inc.php');
			}
		}
	}
	@ eval ('$langvar = $'.$variable.';'); // Note (RH): $$var doesn't work with arrays, see PHP doc
	if (isset ($langvar) && is_string($langvar) && strlen($langvar) > 0)
	{
		return str_replace("\\'", "'", $langvar);
	}
	@ eval ('$langvar = $lang'.$variable.';');
	if (isset ($langvar) && is_string($langvar) && strlen($langvar) > 0)
	{
		return str_replace("\\'", "'", $langvar);
	}
	if ($notrans != 'DLTT')
		return $ot.$variable.$ct;
	if (!is_array($language_files))
	{
		$language_file = $language_files;
	}
	else
	{
		$language_file = implode('.inc.php',$language_files);
	}
	return $ot.$variable.$ct."<a href=\"http://www.dokeos.com/DLTT/suggestion.php?file=".$language_file.".inc.php&amp;variable=$".$variable."&amp;language=".$language_interface."\" style=\"color:#FF0000\"><strong>#</strong></a>";
}

/**
 * Gets the current interface language
 * @return string The current language of the interface
 */
function api_get_interface_language()
{
	global 	$language_interface;
	return $language_interface;
}

/*
==============================================================================
		USER PERMISSIONS
==============================================================================
*/
/**
* Check if current user is a platform administrator
* @return boolean True if the user has platform admin rights,
* false otherwise.
*/
function api_is_platform_admin($allow_sessions_admins = false)
{
	if($_SESSION['is_platformAdmin'])
		return true;
	else
	{
		global $_user;
		if($allow_sessions_admins && $_user['status']==SESSIONADMIN)
			return true;
	}
	return false;
}
/**
 * Check if current user is allowed to create courses
* @return boolean True if the user has course creation rights,