core-bundle/src/Resources/contao/elements/ContentMedia.php
public function generate()
	{
		if ($this->playerSRC == '')
		{
			return '';
		}

		$source = StringUtil::deserialize($this->playerSRC);

		if (empty($source) || !\is_array($source))
		{
			return '';
		}

		$objFiles = FilesModel::findMultipleByUuidsAndExtensions($source, array('mp4', 'm4v', 'mov', 'wmv', 'webm', 'ogv', 'm4a', 'mp3', 'wma', 'mpeg', 'wav', 'ogg'));

		if ($objFiles === null)
		{
			return '';
		}

		// Display a list of files in the back end
		if (TL_MODE == 'BE')
		{
			$return = '<ul>';

			while ($objFiles->next())
			{
				$objFile = new File($objFiles->path);
				$return .= '<li>' . Image::getHtml($objFile->icon, '', 'class="mime_icon"') . ' <span>' . $objFile->name . '</span> <span class="size">(' . $this->getReadableSize($objFile->size) . ')</span></li>';
			}

			$return .= '</ul>';

			if ($this->headline != '')
			{
				$return = '<'. $this->hl .'>'. $this->headline .'</'. $this->hl .'>'. $return;
			}

			return $return;
		}

		$this->objFiles = $objFiles;

		return parent::generate();
	}
public function generate()
	{
		if ($this->playerSRC == '')
		{
			return '';
		}

		$source = StringUtil::deserialize($this->playerSRC);

		if (empty($source) || !\is_array($source))
		{
			return '';
		}

		$objFiles = FilesModel::findMultipleByUuidsAndExtensions($source, array('mp4', 'm4v', 'mov', 'wmv', 'webm', 'ogv', 'm4a', 'mp3', 'wma', 'mpeg', 'wav', 'ogg'));

		if ($objFiles === null)
		{
			return '';
		}

		// Display a list of files in the back end
		if (TL_MODE == 'BE')
		{
			$return = '<ul>';

			while ($objFiles->next())
			{
				$objFile = new File($objFiles->path);
				$return .= '<li>' . Image::getHtml($objFile->icon, '', 'class="mime_icon"') . ' <span>' . $objFile->name . '</span> <span class="size">(' . $this->getReadableSize($objFile->size) . ')</span></li>';
			}

			$return .= '</ul>';

			if ($this->headline != '')
			{
				$return = '<'. $this->hl .'>'. $this->headline .'</'. $this->hl .'>'. $return;
			}

			return $return;
		}

		$this->objFiles = $objFiles;

		return parent::generate();
	}
Return if there are no files

@return string