The enabled() method, called without any parameters, will return the current enabled state of the Upload component.
The enabled(bool) method is used to update the Upload enabled/disabled state. Passing true will enable and false will disable the widget.

<input type="file" name="files" id="files" />

<script type="text/javascript">
    jQuery(function ($) {
            async: {
                enabled: true,
                save: {
                    url: "/upload/save"
                remove: {
                    url: "/upload/remove"

        // disable the upload