EDIT: There is now a queuecomplete
event that you can use for exactly that purpose.
Previous answer:
Paul B.'s answer works, but an easier way to do so, is by checking if there are still files in the queue or uploading whenever a file completes. This way you don't have to keep track of the files yourself:
Dropzone.options.filedrop = {
init: function () {
this.on("complete", function (file) {
if (this.getUploadingFiles().length === 0 && this.getQueuedFiles().length === 0) {
doSomething();
}
});
}
};