It appears no one has yet found a way to detect the post return in the browser itself, but there is another possibility using AJAX. It is a bit more involved though:
<script type="text/javascript">
$(function () {
$('#submitbtn').click (function () {
window.setTimeout (dldone, 100);
return true;
});
function dldone () {
$.get ("/downloadstatus?rand="+$('#rand').val (), function (data) {
if (data == 'done') {
// data generation finished, do something
} else {
window.setTimeout (dldone, 100);
}
});
}
});
</script>
<form action="/generatedata" method="post">
<input type="hidden" id="rand" value="[RANDOMVALUE]">
<input type="submit" id="submitbtn" value="Download Data">
</form>
On the server, you would have to do some inter-process-communication to signal when the data generation is done. Since I already have a database, I did it like this:
public function downloadstatusAction () {
if ($this->db->fetchOne ("SELECT rand FROM dlstatus WHERE rand = ?", (int) $_GET["rand"])) {
$db->delete ("dlstatus", array ("rand = ?" => (int) $_GET["rand"]));
print "done";
} else {
print "loading";
}
}
public function generatedataAction () {
// generate data
$this->db->insert ("dlstatus", array ("rand" => (int) $_POST["rand"]));
// output data
}
I am sure there are more elegant ways to do this, but you get the idea. This appears to work fine in all browsers I tested.
