Boostrap multiselect knockout bindings for objects.

ko.boostrap-multselect.js

    if (typeof ko !== 'undefined' && ko.bindingHandlers && !ko.bindingHandlers.multiselect) {
        ko.bindingHandlers.multiselect = {
            after: ['options', 'value', 'selectedOptions', 'enable', 'disable'],
            preprocess: function (value, name, addBindingCallback) {
                var option = eval('(' + value + ')') || {};
                if (option.observableKey) {
                    addBindingCallback('optionsAfterRender', 'function(option, item) { ko.applyBindingsToNode(option, { attr: { "data-key": (item || {})["' +
                        option.observableKey +
                    '"] } }, item) }');
                }

                return value;
            },
            init: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
                var $element = $(element);
                var config = ko.toJS(valueAccessor());

                $element.multiselect(config);

                if (allBindings.has('options')) {
                    var options = allBindings.get('options');
                    if (ko.isObservable(options)) {
                        ko.computed({
                            read: function () {
                                options();
                                setTimeout(function () {
                                    var ms = $element.data('multiselect');
                                    if (ms)
                                        ms.updateOriginalOptions();//Not sure how beneficial this is.
                                    $element.multiselect('rebuild');
                                }, 1);
                            },
                            disposeWhenNodeIsRemoved: element
                        });
                    }
                }

                //value and selectedOptions are two-way, so these will be triggered even by our own actions.
                //It needs some way to tell if they are triggered because of us or because of outside change.
                //It doesn't loop but it's a waste of processing.
                if (allBindings.has('value')) {
                    var value = allBindings.get('value');
                    if (ko.isObservable(value)) {
                        ko.computed({
                            read: function () {
                                value();
                                setTimeout(function () {
                                    $element.multiselect('refresh');
                                }, 1);
                            },
                            disposeWhenNodeIsRemoved: element
                        }).extend({ rateLimit: 100, notifyWhenChangesStop: true });
                    }
                }

                //Switched from arrayChange subscription to general subscription using 'refresh'.
                //Not sure performance is any better using 'select' and 'deselect'.
                if (allBindings.has('selectedOptions')) {
                    var selectedOptions = allBindings.get('selectedOptions');
                    if (ko.isObservable(selectedOptions)) {
                        ko.computed({
                            read: function () {
                                // Added to handle knockout binding to an object...not just a value
                                // multiselect needs the selected property on the options, else it wont show them on refresh
                                if ((config.optionsKey !== undefined) &&
                                    (config.optionsKey !== null) &&
                                    (config.optionsKey.length > 0) &&
                                    (config.observableKey !== undefined) &&
                                    (config.observableKey !== null) &&
                                    (config.observableKey.length > 0)) {
                                    var observableKey = config.observableKey;
                                    var selectedValues = selectedOptions()
                                        .map(function(selectedOption) {
                                            return ko.isObservable(selectedOption[observableKey])
                                                ? selectedOption[observableKey]()
                                                : selectedOption[observableKey];
                                        });
                                    setTimeout(function () {
                                        $element.multiselect('rebuild');
                                    }, 1);
                                    if (selectedValues.length) {
                                        setTimeout(function () {
                                            $element.multiselect('select', selectedValues);
                                        }, 1);
                                    }
                                }

                            },
                            disposeWhenNodeIsRemoved: element
                        }).extend({ rateLimit: 100, notifyWhenChangesStop: true });
                    }
                }

                var setEnabled = function (enable) {
                    setTimeout(function () {
                        if (enable)
                            $element.multiselect('enable');
                        else
                            $element.multiselect('disable');
                    });
                };

                if (allBindings.has('enable')) {
                    var enable = allBindings.get('enable');
                    if (ko.isObservable(enable)) {
                        ko.computed({
                            read: function () {
                                setEnabled(enable());
                            },
                            disposeWhenNodeIsRemoved: element
                        }).extend({ rateLimit: 100, notifyWhenChangesStop: true });
                    } else {
                        setEnabled(enable);
                    }
                }

                if (allBindings.has('disable')) {
                    var disable = allBindings.get('disable');
                    if (ko.isObservable(disable)) {
                        ko.computed({
                            read: function () {
                                setEnabled(!disable());
                            },
                            disposeWhenNodeIsRemoved: element
                        }).extend({ rateLimit: 100, notifyWhenChangesStop: true });
                    } else {
                        setEnabled(!disable);
                    }
                }

                ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                    $element.multiselect('destroy');
                });
            },

            update: function (element, valueAccessor, allBindings, viewModel, bindingContext) {
                var $element = $(element);
                var config = ko.toJS(valueAccessor());

                $element.multiselect('setOptions', config);
                $element.multiselect('rebuild');
            }
        };
    }