progress bar

gistfile1.txt

---- download action -----
 $session = new Session();
        $session->set('downloadPercent',0);
        $filesize = filesize($filePath);

        $handle = fopen($filePath, 'rb');

        header( 'Content-Disposition: attachment; filename="' .$fallbackFilename . '"' );
        header( 'Pragma: no-cache' );

        $curr_kb=0;
        while($chunk = fread($handle, 1000)) // chunk size may depend on your filesize
        {
            echo $chunk;
            flush();
            $curr_kb+=1000;
            $percent = ceil(($curr_kb / $filesize) * 100);
             $session->set('downloadPercent',$percent);
        }

        fclose($handle);
        
        
---- progress action ----
/**
     * @Route("/getProgress", name="getDownloadProgress")
     * @Template()
     */
    public function getDownloadProgressAction()
    {
        $session = new Session();
        $response = new Response(json_encode( $session->get('downloadPercent')));
        $response->headers->set('Content-Type', 'application/json');
        return $response;
    }
    
    
---- ajax & html -----    

 <div id="downloadBar"  class="progress progress-striped" style="display:none; margin-top: 20px;margin-bottom: 20px">
                        <div id="progress-bar" class="progress-bar progress-bar-info" style="width: 0%"></div>
                    </div>
                    
<script>
    function GetProgress() {
        $.ajax({
            url: "{{ path("getDownloadProgress") }}",
            success: function (data) {
                $("#progress-bar").css('width', Math.round(data) + '%')

                if (Math.round(data) >= 100) {
                    isDone = true;
                    $("#downloadBar").hide();
                } else {
                    setTimeout(GetProgress(), 2000);
                }
            }
        });
    }


    $(".downloadHref").click(
            function() {
                $("#downloadBar").show();
                GetProgress();
            }
    );

</script>