application.js

//= require bootbox.min

custom.js

$(document).ready(function() {
	$.rails.allowAction = function(element) {
	var message = element.data('confirm'),
		answer = false, callback;
	if (!message) { return true; }

	if ($.rails.fire(element, 'confirm')) {
		myCustomConfirmBox(message, function() {
			callback = $.rails.fire(element,
				'confirm:complete', [answer]);
				if(callback) {
					var oldAllowAction = $.rails.allowAction;
					$.rails.allowAction = function() { return true; };
					element.trigger('click');
					$.rails.allowAction = oldAllowAction;
				}
			});
		}
		return false;
	}

	function myCustomConfirmBox(message, callback) {
		bootbox.confirm(message, "Cancel", "Yes", function(confirmed) {
			if(confirmed){
				callback();
			}
		});
	}
});