code: private function applyLegacyLogic($strUrl, $strParams)
  	{
  		// Decode sprintf placeholders
  		if (strpos($strParams, '%') !== false)
  		{
  			@trigger_error('Using sprintf placeholders in URLs has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);
  
  			$arrMatches = array();
  			preg_match_all('/%([sducoxXbgGeEfF])/', $strParams, $arrMatches);
  
  			foreach (array_unique($arrMatches[1]) as $v)
  			{
  				$strUrl = str_replace('%25' . $v, '%' . $v, $strUrl);
  			}
  		}
  
  		// HOOK: add custom logic
  		if (isset($GLOBALS['TL_HOOKS']['generateFrontendUrl']) && \is_array($GLOBALS['TL_HOOKS']['generateFrontendUrl']))
  		{
  			@trigger_error('Using the "generateFrontendUrl" hook has been deprecated and will no longer work in Contao 5.0.', E_USER_DEPRECATED);
  
  			foreach ($GLOBALS['TL_HOOKS']['generateFrontendUrl'] as $callback)
  			{
  				$strUrl = System::importStatic($callback[0])->{$callback[1]}($this->row(), $strParams, $strUrl);
  			}
  
  			return $strUrl;
  		}
  
  		return $strUrl;
  	}
docs: Modifies a URL from the URL generator.
  
  @param string $strUrl
  @param string $strParams
  
  @return string