Enable / Disable State

(function() {
 var uploader = new MultipleUpload('#demo', {
 uploadUrl: '/api/upload',
 multiple: true
 });
 document.getElementById('toggle-btn').addEventListener('click', function() {
 if (uploader.isEnabled()) {
 uploader.disable();
 document.getElementById('state-label').textContent = 'Disabled';
 } else {
 uploader.enable();
 document.getElementById('state-label').textContent = 'Enabled';
 }
 });
})();

Turning the control off and on

disable() and enable() are methods on the instance rather than options, because this is a state that changes while the page is open. Disabling blocks new selections and drops; enabling restores them.

What it is usually wired to

A form that is mid-submit, a quota that has been reached, a plan limit, or a step in a wizard the user has not got to yet. The point is that the reason is visible: pair the call with a message saying why, because a control that simply stops responding reads as a bug.