Symfony 1.x http header for PDF with DOMPDF

dummy.php

<?php 
class showDocumentAction extends sfActions
{
    /**
     * Make sure that no other content will be output
     */
    public function preExecute()
    {
        $this->setLayout(false);
        sfConfig::set('sf_web_debug', false);
        $this->getResponse()->clearHttpHeaders();
    }
    
    /**
     * @param sfRequest $request
     * @return int|string
     * @throws Exception
     * @throws sfException
     */
    public function execute($request)
    {
        $this->environment = sfConfig::get('sf_environment');

        $module = $request->getParameter('type');
        $action = $request->hasParameter('handler') ? $request->getParameter('handler') : 'print';

        $html = $this->getController()->getPresentationFor($module, $action);
        $baseKey = 'mod_' . $module . '_' . $action . '_';
        $config  = sfConfig::has($baseKey . 'config') ? sfConfig::get($baseKey . 'config') : false;

        if($request->hasParameter('debug') && $this->environment == 'dev')
        {
            return $this->renderText($html);
        }

        $document = new PluginPrefixDomPdf;
        $output   = $this->apply($document->generateFrom($html), $config);

        // The PDF document should not be saved on the filesystem
        if($output == 'stream')
        {
            $this->renderText($document->stream($action));

            return sfView::NONE;
        }

        $document->setTargetFile($action);

        if($request->hasParameter('overwrite') && file_exists($document->getFile()) && $this->environment == 'dev')
        {
            unlink($document->getFile());
        }

        if(!file_exists($document->getFile()))
        {
            $document->save();
        }

        return $this->output($document->getFile());
    }

    /**
     * @param DOMPDF $document
     * @param        $overrides
     * @return string
     */
    protected function apply(DOMPDF $document, $overrides)
    {
        if($overrides == false || !is_array($overrides))
        {
            return 'save';
        }

        extract($overrides);

        if(isset($width) && isset($height))
        {
            $document->set_paper(array(0, 0, $width, $height));
        }

        if(isset($paper) && isset($orientation))
        {
            $document->set_paper($paper, $orientation);
        }

        return isset($output) ? $output : 'save';
    }
    
    /**
     * @param $filePath
     * @return int
     * @throws sfError404Exception
     */
    protected function output($filePath)
    {
        $this->forward404Unless(file_exists($filePath));

        $this->getResponse()->setHttpHeader('Pragma', 'public');
        $this->getResponse()->setContentType(mime_content_type($filePath));
        $this->getResponse()->setHttpHeader('Content-Length', filesize($filePath));
        $this->getResponse()->setHttpHeader('Content-Transfer-Encoding', 'binary');
        $this->getResponse()->setHttpHeader('Content-Description', 'File Transfer');
        $this->getResponse()->setHttpHeader('Cache-Control', 'public, must-revalidate');
        $this->getResponse()->setHttpHeader('Content-Disposition', 'inline; filename="' . basename($filePath) . '"');
        $this->getResponse()->sendHttpHeaders();

        ob_end_flush();
        $this->getResponse()->setContent(readfile($filePath));

        return sfView::HEADER_ONLY;
    }
}