asyncDdownloader

Download from async process without popups

Situation

You have to get a download url from a service like s3 once the response comes back with the url you need to use window.open to initiate the download.

Problem 1

window.open creates an orphaned window/tab on some browsers

Problem 2

Because of the async process to get the url window.open is called from the main event loop not a direct user action, thus a popup blocker is initiated

Problem 3

I need to download many files at once with one click

Solution

Immediately open a hidden iFrame window with no url once the async response to fetch the download url returns we can call window.open on this remoteWindow with our download url this call magically retains user level privileges, hence no popup blocker. This works for any number of files at the same time just create a new instance for each.

Usage

• 1. get a new downloader instance var asyncDl = asyncDownloader();
• 2. in some async callback call download with your href asyncDl.download(href);
• 3. no matter what happens call cleanup asyncDl.cleanup();