core-bundle/src/Resources/contao/widgets/Upload.php
protected function validator($varInput)
	{
		$strUploadTo = 'system/tmp';

		// Specify the target folder in the DCA (eval)
		if (isset($this->arrConfiguration['uploadFolder']))
		{
			$strUploadTo = $this->arrConfiguration['uploadFolder'];
		}

		return $this->objUploader->uploadTo($strUploadTo);
	}
protected function validator($varInput)
	{
		$strUploadTo = 'system/tmp';

		// Specify the target folder in the DCA (eval)
		if (isset($this->arrConfiguration['uploadFolder']))
		{
			$strUploadTo = $this->arrConfiguration['uploadFolder'];
		}

		return $this->objUploader->uploadTo($strUploadTo);
	}
Trim values

@param mixed $varInput

@return mixed