Is it possible to catch browser's File Open/Save dialog event using Javascript
Yes! You can take advantage that most browsers (Tested okay on Chrome, Firefox, and IE) fire the beforeunload event just before the Individual-file Download dialog opens.
So code like this will work:
$(window).bind ("beforeunload", function (zEvent) {
// PERFORM DESIRED ACTIONS HERE.
/* This code will fire just before the Individual-file Download
dialog opens.
Note that it will also fire before the tab or window is closed,
but that should not be a problem for this application.
*/
} );
Open and run this snippet to see it in action:
$(window).bind ("beforeunload", function (zEvent) {
$("#dwnldStatus").text ("This code runs just before the file open/save dialog pops up.");
} );
$("#directDwnload").click ( function () {
fireDownload ();
} );
$("#ResetTimer").click ( function () {
$("#dwnldStatus").html (
'Download will start in <span id="timeleft">3</span> seconds.'
);
fireTimer (3);
} );
function fireDownload () {
window.location.assign (
"//phs.googlecode.com/files/Download%20File%20Test.zip"
);
}
function fireTimer (secondsLeft) {
this.secondsLeft = secondsLeft || 30;
this.countdownTimer = this.countdownTimer || null;
if ( ! this.countdownTimer) {
this.countdownTimer = setInterval ( function() {
this.secondsLeft--;
$("#timeleft").text (this.secondsLeft);
if (this.secondsLeft <= 0) {
clearInterval (this.countdownTimer);
this.countdownTimer = null;
fireDownload ();
}
},
1000
);
}
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<p>Activate one of the download buttons. The timer button is just like any other javascript initiated download, no additional click is needed.</p>
<p>The javascript detects when the File/Save dialog pops up and changes the status to "This code runs just before the file open/save dialog pops up.".</p>
<p>Note that it is not necessary to download the file. You can cancel the download.</p>
<div id="dwnldStatus"></div>
<button id="ResetTimer">Set timer to 3 seconds.</button>
<button id="directDwnload">Download the file now.</button>Note that beforeunload will also fire before the tab or window is closed, so plan accordingly. That should not be an issue for this question as stated.
No, there is no event for that.