Detect the File Open/Save dialog

by BrockA

HTML

<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>

JavaScript

$(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
        );
    }
}