KnockoutJS binding with Twitter Bootstrap's modal dialog

ko.bindings.modal.js

ko.bindingHandlers.modal = {
    init: function (element, valueAccessor, bindingsAccessor, viewModel, bindingContext) {
        var $element = $(element);
        $element.addClass('hide modal');
        $element.modal({
            show: false
        });

        var bindings = bindingsAccessor();
        if (bindings.modalOptions) {
            if (bindings.modalOptions.beforeClose) {
                $element.on('hide', function () {
                    return bindings.modalOptions.beforeClose();
                });
            }
        }

        return ko.bindingHandlers['with'].init.apply(this, arguments);
    },
    update: function (element, valueAccessor, bindingsAccessor, viewModel, bindingContext) {
        var value = ko.utils.unwrapObservable(valueAccessor());
        var returnValue = ko.bindingHandlers['with'].update.apply(this, arguments);

        var $element = $(element);
        if (value) {
            $element.modal('show');
            setTimeout(function () {
                $element.find('input').filter(':first').focus();
            }, 200);
        }
        else
            $element.modal('hide');

        return returnValue;
    }
};