core-bundle/src/Resources/contao/dca/tl_files.php
public function uploadFile($row, $href, $label, $title, $icon, $attributes)
	{
		if (!$GLOBALS['TL_DCA']['tl_files']['config']['closed'] && !$GLOBALS['TL_DCA']['tl_files']['config']['notCreatable'] && Contao\Input::get('act') != 'select' && isset($row['type']) && $row['type'] == 'folder')
		{
			return '<a href="'.$this->addToUrl($href.'&amp;pid='.$row['id']).'" title="'.Contao\StringUtil::specialchars($title).'" '.$attributes.'>'.Contao\Image::getHtml($icon, $label).'</a> ';
		}

		return ' ';
	}
public function uploadFile($row, $href, $label, $title, $icon, $attributes)
	{
		if (!$GLOBALS['TL_DCA']['tl_files']['config']['closed'] && !$GLOBALS['TL_DCA']['tl_files']['config']['notCreatable'] && Contao\Input::get('act') != 'select' && isset($row['type']) && $row['type'] == 'folder')
		{
			return '<a href="'.$this->addToUrl($href.'&amp;pid='.$row['id']).'" title="'.Contao\StringUtil::specialchars($title).'" '.$attributes.'>'.Contao\Image::getHtml($icon, $label).'</a> ';
		}

		return ' ';
	}
Return the upload file button

@param array  $row
@param string $href
@param string $label
@param string $title
@param string $icon
@param string $attributes

@return string