For the alert about whether or not folder upload is supported it makes sense to externalize that and detect it ahead of time i.e. with modernizr.

We could probably do something special when a folder has been added via one of the listeners, i.e. as in the alert above.

FYI I did get a dropzone dev environment setup and realized that the queue modification broke about 10 unit tests, this is when I reevaluated the patch and understood what processQueue was doing and reimplemented it with the the help of their listeners. Basically processQueue starts the processing and with parallel processing set to 1 after each file completes and if there are more process the next one until a there are no more files and a queuecomplete event is emitted.

FYI I have suggested something similar in https://github.com/enyo/dropzone/issues/528

> The only thing I miss from my previous changes is an alert that I programmed when a folder is dropped in a non-compatible browser.

My suggestion would be to submit this as an upstream pull-request or an upstream issue to the Dropzone.js:

https://github.com/enyo/dropzone/issues

Thank you so much for this change! This is much better than before and updating dropzone to 3.8.4 fixes some issues I had to manage by my own.

The only thing I miss from my previous changes is an alert that I programmed when a folder is dropped in a non-compatible browser. When adding a file, if a folder is dropped and the browser does not support it, all these three conditions happens:

if ((!file.size) && (!file.type) && (!file.fullPath))
{
alert("Folder upload is not supported by your current browser. Currently, only Chrome 21 or upper allows it.");
}

This worked in the three major browsers I tested it (Firefox, Chrome and Internet Explorer). Currently this change is not in the code and a folder dropped in the dropzone fails silently. Don't you think that an alert for users would be useful here?