Zend FR

function downloadAction()
    {
        $id=$this->checkId();
        $this->_helper->layout->disableLayout();
        $documents = Table_Document::getInstance();
        $row=$documents->findRowSimple($id);
        $filePath=$row->document_path;
        $fullPath=$_SERVER['DOCUMENT_ROOT']."/".$filePath;

        if (file_exists($fullPath)) {
            $file = file_get_contents($fullPath);
            $this->view->row = $row;
            $this->view->file = $file;
        }else{
            $this->redirectFileNotFound();
        }
    }

<?php if(isset($this->row)){
    header('Content-type: '.$this->row['document_type']);
    header('Content-Disposition: attachment; filename="'.$this->row['document_name'].'"');
    echo $this->file;
}else{
    echo "Error : File not found on the server";
}
?>