TCPDF Progress Bar - php

Question

I am using php and TCPDF to generate a custom PDF file from several MySQL queries. Once the user clicks the "Generate PDF" button a new tab opens and the PDF process starts. It takes, on average, about 10 seconds to build the PDF. Once the file is ready the browser closes the blank page and displays the save as dialog window.
I'd like to display some type of message to the user while the PDF is creating. I am somewhat of a noob when it comes to AJAX/JQUERY, but have tried to implement several solutions without success.
Things to note:
The backend is Joomla!
Using $pdf->Output('example.pdf','D') to generate the pdf
Using ob_end_clean prior to $pdf-Output to avoid the "TCPDF: Data already output" error.
I have tried the method that adds a <div> to the end of my page as well as some jQuery/CSS that would show an animated gif while the page is loading. It did not work, and I somehow get the feeling this is either caused by the ob_end_clean or the Joomla! framework.

Answer 1

1) for progress bar you must run the script via ajax
2)you have pdf page count...on each page creating you can change progress bar value
3)you must use php output control function for each pages of pdf created
php have a list of good function for this
i dont see your code but you must do some thing like this
$i = 1;
while($i< PDF_PAGE_COUNT){
ob_start();
pdf_create_page($i);
echo $i/PDF_PAGE_COUNT;
ob_flush();
flush();
$i++;
}
p.s : for better answer please paste your code here!

Answer 2

$(document).ready(function(){
$("#PDF").click(function(){
/*-------------- validate filters -------------------------------*/
if(!(validarFecha(fecha_ymd(rj.Get('#TxtFechaIni').value())))){Warn2.show();return false; }
if(!(validarFecha(fecha_ymd(rj.Get('#TxtFechaFin').value())))){Warn3.show();return false; }
if(Date.parse(fecha_ymd(rj.Get('#TxtFechaIni').value()))>=Date.parse(fecha_ymd(rj.Get('#TxtFechaFin').value()))){Warn.show();return false; }
/* is alll right */
else {
/* show a message while generating report*/
WinSnd.Message({type:'info', title:'generating report', value:'Please, wait ...', buttons:' '}).show();
/* url with params to send */
var url="report.php?&slash="+'<?php echo(isset($_POST['slash'])?#$_POST['slash']:#$_GET['slash']);?>'+"&module="+'<?php echo (isset($_POST['module'])?#$_POST['module']:#$_GET['module']);?>'
+"&TxtCheck=excel"
+"&TxtFechaIni="+rj.Get('#TxtFechaIni').value()
+"&TxtFechaFin="+rj.Get('#TxtFechaFin').value()
+"&LkpTdoc="+rj.Get('#LkpTdoc').value();
var filename = <?php echo '"'.$gSave.'"';?>; /* name for report, i set*/
var xhr = new XMLHttpRequest();
xhr.responseType = 'blob';
xhr.onload = function(){
WinSnd.hide(); /* hide message */
var a = document.createElement('a');
a.href = window.URL.createObjectURL(xhr.response); // xhr.response es un blob file
a.target = '_blank';
a.download = filename; // file name
a.style.display = 'none';
document.body.appendChild(a);
a.click(); // action
delete a; //
};
xhr.open('GET', url);
xhr.send();
}// fin validaciones
});//fin function
});// fin