core-bundle/src/Resources/contao/classes/FileUpload.php
public function generateMarkup()
	{
		$return = '
  <div>
    <input type="file" name="' . $this->strName . '[]" class="tl_upload_field" onfocus="Backend.getScrollOffset()" multiple required>
  </div>';

		if (isset($GLOBALS['TL_LANG']['tl_files']['fileupload'][1]))
		{
			$return .= '
  <p class="tl_help tl_tip">' . sprintf($GLOBALS['TL_LANG']['tl_files']['fileupload'][1], System::getReadableSize(static::getMaxUploadSize()), Config::get('gdMaxImgWidth') . 'x' . Config::get('gdMaxImgHeight')) . '</p>';
		}

		return $return;
	}
public function generateMarkup()
	{
		$return = '
  <div>
    <input type="file" name="' . $this->strName . '[]" class="tl_upload_field" onfocus="Backend.getScrollOffset()" multiple required>
  </div>';

		if (isset($GLOBALS['TL_LANG']['tl_files']['fileupload'][1]))
		{
			$return .= '
  <p class="tl_help tl_tip">' . sprintf($GLOBALS['TL_LANG']['tl_files']['fileupload'][1], System::getReadableSize(static::getMaxUploadSize()), Config::get('gdMaxImgWidth') . 'x' . Config::get('gdMaxImgHeight')) . '</p>';
		}

		return $return;
	}
Generate the markup for the default uploader

@return string