public function getParentFolder($force = FALSE) {
		
		if(!isset($this->parentFolder) || $force) {
			
			$parentPath = realpath($this->path . '..');
			
			// flag parentFolder property, when $this is already the root folder
			
			if($parentPath === $this->path) {
				$this->parentFolder = FALSE;
			}

			else {
				$this->parentFolder = self::getInstance($parentPath);
			}

		}

		// return NULL (instead of FALSE) when there is no parent folder

		return $this->parentFolder ?: NULL;
		
	}
public function getParentFolder($force = FALSE) {
		
		if(!isset($this->parentFolder) || $force) {
			
			$parentPath = realpath($this->path . '..');
			
			// flag parentFolder property, when $this is already the root folder
			
			if($parentPath === $this->path) {
				$this->parentFolder = FALSE;
			}

			else {
				$this->parentFolder = self::getInstance($parentPath);
			}

		}

		// return NULL (instead of FALSE) when there is no parent folder

		return $this->parentFolder ?: NULL;
		
	}
public function getParentFolder ( $ force = FALSE ) { if ( ! isset ( $ this -> parentFolder ) || $ force ) { $ parentPath = realpath ( $ this -> path . '..' ) ; // flag parentFolder property, when $this is already the root folder if ( $ parentPath === $ this -> path ) { $ this -> parentFolder = FALSE ; } else { $ this -> parentFolder = self :: getInstance ( $ parentPath ) ; } } // return NULL (instead of FALSE) when there is no parent folder return $ this -> parentFolder ? : NULL ; }
return parent FilesystemFolder of current folder
returns NULL, when current folder is already the root folder

@param boolean $force
@return FilesystemFolder
return parent FilesystemFolder of current folder returns NULL when current folder is already the root folder