TYPO3 Core

<?php
namespace WIRO\WiroBase\ViewHelpers;

 /**
  * DownloadViewHelper
  */
class DownloadViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractTagBasedViewHelper {

    /**
     * @var string
     */
    protected $tagName = 'a';

    /**
     * Arguments Initialization
     *
     * @return void
     * @see http://docs.typo3.org/typo3cms/ExtbaseFluidBook/8-Fluid/8-developing-a-custom-viewhelper.html#creating-xml-tags-using-tagbasedviewhelper
     */
    public function initializeArguments() {
        $this->registerUniversalTagAttributes();
    }

    /**
     * Generates a secured download link (unlike getPublicUrl this will always result in a download)
     *
     * Usage:
     * <code>
     *     {namespace wiroBase=WIRO\WiroBase\ViewHelpers}
     *
     *     <wiroBase:download resourceObject="{model.file.originalResource.originalFile}" title="Download" class="myDownload">
     *      <div>...</div>
     *     </wiroBase:download>
     *
     *     <a data-download="{wiroBase:download(resourceObject: '{model.file.originalResource.originalFile}', asUri: 1)}">
     *      <div>...</div>
     * </a>
     * </code>
     *
     * @param TYPO3\CMS\Core\Resource\FileInterface $resourceObject File or ProcessedFile
     * @param bool $absolute If set, the URI of the rendered link is absolute
     * @param bool $asUri Return a URI instead <a> tags
     * @return string Rendered link
     * @see \TYPO3\CMS\Core\Resource\ResourceStorage::getPublicUrl()
     */
    public function render(\TYPO3\CMS\Core\Resource\FileInterface $resourceObject, $absolute = FALSE, $asUri = FALSE) {

        $queryParameterArray = array('eID' => 'dumpFile', 't' => '');
        if ($resourceObject instanceof \TYPO3\CMS\Core\Resource\File) {
            $queryParameterArray['f'] = $resourceObject->getUid();
            $queryParameterArray['t'] = 'f';
        } elseif ($resourceObject instanceof \TYPO3\CMS\Core\Resource\ProcessedFile) {
            $queryParameterArray['p'] = $resourceObject->getUid();
            $queryParameterArray['t'] = 'p';
        }

        $queryParameterArray['token'] = \TYPO3\CMS\Core\Utility\GeneralUtility::hmac(
            implode('|', $queryParameterArray),
            'resourceStorageDumpFile'
        );

        $uriBuilder = $this->controllerContext->getUriBuilder();
        $uri = $uriBuilder
            ->reset()
            ->setArguments($queryParameterArray)
            ->setCreateAbsoluteUri($absolute)
            ->uriFor();

        if ($asUri) {
            return $uri;
        }

        $this->tag->addAttribute('href', $uri);
        $this->tag->setContent($this->renderChildren());
        $this->tag->forceClosingTag(TRUE);
        return $this->tag->render();
    }
}