JavaScript从target = _blank提交表单中检索窗口句柄

Question

I'm trying to create an automated script that lets me download various files from a website, then upload them to a new website. The script will let multiple users copy content from the old site to the new one at the same time.

I initially attempted to use AJAX to download one file at a time, and store the file(s) data in variables, then upload this variable (file data) to the second domain. The download worked fine, but the PHP page on the second domain always threw back a 500 request error message AFTER uploading, despite setting various file size parameters and processing time parameters in PHP. This meant I couldnt even see what was echoed by the PHP page to debug, and continue developing that method.

After spending a long time trying to fix this (and failing miserably), I decided to just let the users download the old files normally, then use a form to upload the files. As I want the script to continue to run whilst the file is uploading, I've decided to set the forms target to "_blank" to open a new tab (which uploads the file).

How can I retrieve the windows handle that's opened with the target="_blank" form, to test when the window is closed? I don't need to access the windows HTML, I just want to check when it closes. The page that's opened by the form is not on the same domain as the form that opens it, but the "Access-Control-Allow-Origin" header is set to "*" on the second domains PHP page.

Answer 1

I don't think you can retrieve the window handle, but you can use Javascript to keep a reference to the window and check whether the window is closed or not. You would have to open your window with Javascript like this

var uploadWindow = window.open("http://www.google.com");

Then you can use a function on a timer to monitor if the window has closed or not:

var interval = 250;
setTimeout(checkClose, interval);

function checkClose() {
    if (uploadWindow.closed) {
        // Code to run when window is closed
    }
    else {
        setTimeout(checkClose, interval);
    }
}

I hope this can be of help