code: public function deleteAll()
  	{
  		if ($GLOBALS['TL_DCA'][$this->strTable]['config']['notDeletable'])
  		{
  			throw new InternalServerErrorException('Table "' . $this->strTable . '" is not deletable.');
  		}
  
  		/** @var Session $objSession */
  		$objSession = System::getContainer()->get('session');
  
  		$session = $objSession->all();
  		$ids = $session['CURRENT']['IDS'];
  
  		if (!empty($ids) && \is_array($ids))
  		{
  			$ids = $this->eliminateNestedPaths($ids); // see #941
  
  			foreach ($ids as $id)
  			{
  				$this->delete($id); // do not urldecode() here (see #6840)
  			}
  		}
  
  		$this->redirect($this->getReferer());
  	}
docs: Delete all files and folders that are currently shown
  
  @throws InternalServerErrorException